A report by an ad hoc Committee established by the Ad-visory Council for the National Institute of Neurologicaland Communicative Disorders and Stroke, NationalInstitutes of Health, Bethesda, Maryland 20014.
Reprint requests should be addressed to: Stroke Pro-gram, National Institute of Neurological and Com-municative Disorders and Stroke, National Institutes ofHealth, Bethesda, Maryland 20014.
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A CLASSIFICATION AND OUTLINEOF CEREBROVASCULAR DISEASES II
Table of Contents
Introduction S66Classification of Cerebrovascular Diseases
Part i . Clinical Stage 567Part II . Pathophysiological Mechanisms 568Part III. Anatomy 571Part IV. Pathology 576Part V. Clinical Phenomena (History, Physical Examination, Laboratory Examination,
Roentgen Examination, Other) 584Part VI . Status of Patient (Performance and Placement) 592
Outline of Cerebrovascular Diseases 594Definitions and descriptions of clinical stages 594
troencephalogram, isotope brain scan, x-rays of chest and head, cervical-cerebralangiography) 606
Special proceduresComputerized soft tissue tomography (EMI scanner, ACTA scanner, etc.) 610Cerebral blood flow measurements, thermography and thermometry, retinal
photography, etc 610Appendix
Abbreviated classification (more frequently occurring categories) 613The World Federation of Neurology Code for Grading Atherosclerosis 616Wagener and Keith Classification of Retinal Vascular Disease 616
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CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
Introduction*• The purpose of this "Classification and Outline ofCerebrovascular Diseases II" is: (1) to place inclassified form the known types of cerebrovasculardisease in such a manner that all or a portion of theclassification will be of value to clinicians,pathologists, physiatrists as well as other disciplines;(2) to give practical meaning to the classification bydefining the terms so they can be employed in-terchangeably by clinicians and investigators invarious parts of the country; and (3) to set down inorganized fashion the salient diagnostic criteria for anumber of clinical entities.
Since the time of the deliberations of the first adhoc Committee on Cerebrovascular Disease ofNINDB, there has been considerable expansion of thebody of knowledge concerning cerebrovascular dis-ease. It continues to be evident that in such a complexset of clinical-pathophysiological phenomena somestandard reference language or set of definitionsshould be used or the literature of investigation will beuninterpretable. An example of this: Does the term"transient ischemic attack" include diffuse ischemia(syncope) or is the term limited to episodes of focalischemia? Follow-up data about the frequency ofstroke in patients with the former are entirely differentthan follow-up data concerning patients with thelatter! The second ad hoc Committee onNomenclature of Cerebrovascular Diseases welcomedthe opportunity to continue the task of producing alucid, usable and acceptable classification and set ofdefinitions and diagnostic criteria for standard use. Asin the first "Classification and Outline ofCerebrovascular Diseases," it is recognized that manyof the statements on the following pages are only ten-
*By Clark H. Millikan, M.D., Professor of Neurology, MayoMedical School, Rochester, Minnesota 55901, and Chairman,NINCDS ad hoc Committee on Cerebrovascular Diseases;and committee members: Raymond B. Bauer, M.D., Pro-fessor of Neurology, Wayne State University School of Medi-cine, Detroit, Michigan 48201; John Goldschmidt, M.D.,Professor of Physical Medicine and Rehabilitation, JeffersonMedical College, Philadelphia, Pennsylvania 19100; Murray Gold-stein, D.O., Associate Director, NINCDS, Bethesda, Maryland20014; Albert Heyman, M.D., Professor of Neurology, DukeUniversity School of Medicine, Durham, North Carolina 27706;John Stirling Meyer, M.D., Professor of Neurology, Baylor Collegeof Medicine, Houston, Texas 77025; John Moossy, M.D., Professorof Neuropathology, University of Pittsburgh School of Medicine,Pittsburgh, Pennsylvania 15213; Lester Mount, M.D., Professor ofNeurosurgery, College of Physicians and Surgeons, ColumbiaUniversity, New York, New York 10032; Robert G. Siekert, M.D.,Professor of Neurology, Mayo Medical School, Rochester,Minnesota 55901; Reuel Stallones, M.D., Professor of PublicHealth, University of Texas School of Public Health, Houston,Texas 77025; James F. Toole, M.D., Professor of Neurology, Bow-man Gray School of Medicine, Winston-Salem, North Carolina27103.
Special Consultants: O. M. Reinmuth, M.D., Professor ofNeurology, University of Miami School of Medicine, Miami,Florida 33152; Peritz Scheinberg, M.D., Professor of Neurology,University of Miami School of Medicine, Miami, Florida 33152.
tative ones and, as understanding of mechanisms andcauses increases, some of these statements will need tobe changed.
By the term "cerebrovascular" we denote all dis-orders in which there is an area of brain transiently orpermanently affected by ischemia or bleeding, or inwhich one or more brain blood vessels are primarilyinvolved in a pathological process, or a combinationof the two. The former includes such phenomena as asudden change in cardiac rhythm causing a decreasedarterial perfusion pressure to the brain, the temporaryredistribution of blood in "hemiplegic migraine," etc.,while under pathological process are included abnor-malities of the blood vessel wall, stenosis or occlusionby thrombus or embolus, and altered permeability toplasma and blood cells.
The term "cerebrovascular" is now well es-tablished and designates this whole category of dis-eases. "Cerebrovascular" and "cerebral" are used inthe original Latin sense, referring to the whole brainand not merely to the hemispheres of the forebrain.
BASIS OF THE CLASSIFICATION
The Basis of the Classification has been changed as itis no longer possible to fill the spectrum of clinical andresearch needs with a classification which is limited topathology. As the Committee reviewed the first"Classification and Outline of CerebrovascularDiseases," it was apparent that a different approachwould be required in order to classify: (a) the temporalprofile of development of a cerebrovascular abnor-mality, (b) such transient pathophysiologicalmechanisms as vasospasm, changes in cardiacrhythm, systemic hypotension, hypercapnia, etc., (c)anatomical parameters of the blood vessel system orof the brain and spinal cord, (d) neurological clinicalphenomena whether history, physical examination,laboratory results, etc., and (e) the performancecapabilities of the patient related to the placement re-quirements of the patient when changing care status,whether hospital to home, nursing home, etc.
Therefore, the revised Classification is based ondivision into six parts: Part I. Clinical Stage, Part II.Pathophysiological Mechanisms, Part III. Anatomy(blood vessels, brain), Part IV. Pathology (bloodvessels, brain), Part V. Clinical Phenomena, and PartVI. Status of Patient (Performance and Placement).This division into six parts makes it possible to classifyany cerebrovascular problem, at any point in time,and also makes it possible for individuals with somespecial interest or need concerning one or two parts tofulfill those selective needs. As is so often true inclinical medicine, sequential reclassification in Part I(Clinical Stage) will often be necessary as a patient'sproblem proceeds through progressing cerebral infarc-tion to completed cerebral infarction. Various com-binations, of course, may occur. Part VI (PatientStatus) may not be used until some time into apatient's hospital course, and Part V (Clinical
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Phenomena) may be only partially completed in manyinstances. The idea of "thinking through" the entireclassification, as the busy physician deals with apatient problem, is paramount as the Classificationprovides an orderly format for proceeding fromclinical stage to pathophysiological mechanism —anatomical locus of the process — pathology —clinical phenomena including neurovascular examina-tion and laboratory evaluation to the patient'scapability status with or without need for specialplacement. In certain instances, a process or diseasehad to be listed under more than one major category,i.e., thrombosis under Pathophysiological Mech-anisms and Pathology, and embolism in the same twosubdivisions.
An attempt has been made to make theClassification, or some portion of it, serviceable to thevarious disciplines dealing with clinical service, train-ing or research concerning the CerebrovascularDiseases. In the interest of practicability and to assistthe student, bold-faced type has been used for thecommon disorders. References to the location of itemsin the Outline are included in the Classification.
Part I. Clinical StageINTRODUCTION
The primary purpose of this section of theClassification is to provide a framework for thedescription of the current status of the patient inreference to the temporal profile of the disease withoutregard to other factors, such as etiology, pathology,neural deficit and the like, all of which are described inseparate sections.
As the condition of the patient may be changing,sometimes rapidly, a static description presents cer-tain problems, particularly as to the exact time when apatient is categorized. In general, a patient is placedinto one of the categories at the time he is studied insufficient detail so as to permit a reasonably certainclinical diagnosis. Because of the evolution of thedeficit, it is likely that patients will be in differentcategories at different times; in these instances, astatement must be made to indicate the time ofcategorization. It is possible, also, that some deficitswill be stable while other deficits are evolving; in theseinstances, appropriate comments will need to bemade. By using more than one category, an accuratedescription of a complex temporal profile can be built(e.g., a patient who has transient ischemic attacksfollowed by a completed stroke with a permanentresidual neurological deficit and who subsequentlyagain has transient ischemic attacks would beclassified as I.B.I., I.B.3., and later I.B.I.).
It is obvious that an infinite number of variationscan be discerned among the patterns of cerebro-vascular disease; thus, any classification is somewhatarbitrary. Furthermore, the purist may note somemixing of clinical description with pathological en-tities. The Committee recognized that the rate of
change might be important, but to describe this fullywould lead to too complex a Classification.
Part I. Clinical StageA. Asymptomatic
This category is for cerebrally asymptomatic in-dividuals who are found to have evidence whichmay potentially be important as predisposing tofuture cerebrovascular disease. Such evidence islisted in detail in Part II. Some of the factors inthis evidence have been termed the "Stroke ProneProfile."
B. Focal cerebral dysfunctionThis category refers to focal brain dysfunctionregardless of the nature of the vascular pathology(e.g., ischemic disease, intracranial hemorrhage,arteritis).*1. Transient attacks (transient ischemic attacks)
These are episodes of temporary and focalcerebral dysfunction of vascular origin, whichare variable in duration, commonly lastingfrom 2 to 15 minutes, but occasionally lastingas long as a day (24 hours). They leave no per-sistent neurological deficit. These attacks areusually called transient ischemic attacks (TIA)because their pathogenesis is believed to beischemic. However, in rare instances, it is possi-ble that such attacks may be associated withother types of vascular pathophysiology. (Forcomplete description, see Outline ofCerebrovascular Diseases.)
Many factors might be included todescribe the characteristics of the change or therate of change in each individual attack or thepattern in many attacks. These factors are dealtwith in I.B.2.
2. Actively changing neurological deficitThis category refers to a patient whoseneurological deficit is actively changing inamount during the period of observation(specify duration from time of onset). Thedeficit may be getting more severe or lesssevere.a. Improvingb. Worsening (also known as "stroke-in-
evolution" or "progressing stroke")3. Prolonged neurological deficit
This category refers to a relatively stableneurological deficit, that is, during the period ofobservation for categorization (specify duration
•Migraine syndrome. The aura of migraine (e.g.. scintillatingscotoma) is commonly attributed to focal cerebral ischemia owingto vasoconstriction. In some instances more severe neurologicaldeficits precede the headache and may include hemiparesis.dysphasia and homonymous hemianopia and in the great majorityof instances these deficits are transitory, only rarely persisting longenough to produce a cerebral infarct. The temporal profile may beclassified under "Clinical Stage" while the word "migraine" is un-der II.A.5.b.
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from time of onset) little or no change in thedeficit is occurring.a. Duration more than 24 hours and less than
three weeks (sometimes referred to as areversible ischemic neurological deficit orRIND)
b. Duration more than three weeks; often per-manent (commonly known as "completedstroke")
C. General cerebral dysfunctionThis category refers to general cerebral ischemia,which results from reduction in blood supply to thebrain, yet is applicable also to lesions of othercauses. This category does not imply the presenceor absence of disease of the cerebral arteries.f1. Transient
Brief episodes of general cerebral ischemia, theclassic example of which is simple fainting. It ispossible that loss of consciousness may resultfrom ischemia of focal areas of the brain, areaswhose integrity is required for maintenance ofconsciousness; in those instances in which adecision can be made that such episodes are infact focal, the patient should be categorized un-der I.B.
Part II. Pathophysiological MechanismsINTRODUCTION
Clinicians continuously ponder questions aboutmechanisms as they watch events unfold in the courseof an illness. If the mechanisms (pathogenesis) of afocal abnormality of blood supply to the brain can bedetermined, corrective measures often can be in-
tln the present state of our knowledge, chronic dementia of theelderly without clinical or pathological evidence of neurologicaldeficits of vascular origin is rarely caused by cerebralatherosclerosis alone. Although these patients are frequentlydiagnosed as having "arteriosclerotic dementia," "cerebralatherosclerosis with dementia," or "chronic brain syndrome withcerebral atherosclerosis," their conditions are often confused withother toxic, metabolic or degenerative diseases (e.g., Alzheimer'sdisease or senile dementia).
A patient with a focal neurological deficit of vascular origin,e.g., hemiparesis plus a defect in mentation, should be classified un-der I.B.
stituted. There are processes which produce no specifictissue change which ultimately can be identified by thepathologist. These include such common items asthrombosis with lysis, embolism with fragmentation,vasospasm, hypotension, abnormalities of cardiacrhythm, and many others. Consideration of these fac-tors is vital to the formulation of an outline of themechanisms in a specific patient problem. In certaininstances, it may be necessary to list more than onemechanismt e.g., cerebral embolism from a cardiacsource, hypotension and myocardial infarction.
Section E, possible predisposing factors, is in-cluded to record the role of these abnormalities as"risk factors."
As the pathologist works with the problem ofclassifying autopsy findings, he may find it helpful tobe able to use this section on PathophysiologicalMechanisms in instances where the clinical recordcontains such evidence as cholesterol retinal emboliand atrial fibrillation; while the autopsy findings in-clude no cause for a hemorrhagic cerebral infarction.This section may stimulate more detailed search forevidence of some causes of stroke.
Part II. Pathophysiological Mechanisms
A. Primary abnormalities of cerebral circulation(specify transient or persistent)1. Thrombosis
a. Lysisb. Recannulationc. Collateral flow
2. Embolisma. Intraluminal sourceb. Cardiac sourcec. Other source
3. Hemorrhage (specify — see Anatomyand Pathology)
4. Compressiona. Change of position of head, neck or arm
1) Osteoarthritis of cervical vertebrae2) Atlas to axial joint3) Fibrous bands4) Kinks5) Loops6) Fracture
' b. Expanding mass
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2. Hypertension (specify transient or persistent) [See Appendix for grading of retinal changes — Wagenerand Keith Classification]a. Unknown cause, including essentialb. Endocrinec. Medicationd. Renale. Emotionalf. Physical exertiong. Toxemia of pregnancy
C. Alterations in blood1. Viscosity
a. Dehydrationb. Overhydrationc. Other (specify)
2. Cellular constituentsa. Erythrocytes
1) Anemia2) Polycythemia3) Hemoglobinopathy
a) Sicklemiab) Hemoglobin C
b. Leukocytesc. Thrombocytes (e.g., thrombocytosis, thrombocytopenia)
3. Clotting defectsa. Hypercoagulability (specify cause when known, including medication)b. Hypocoagulability (specify cause when known, including medication)
4. Proteinsa. Macroglobulins (specify type if known)b. Cryoglobulinsc. Hyperfibrinogenemiad. Other
5. Lipidsa. Cholesterolb. Triglyceridesc. Lipoproteind. Other
Anatomical structures are considered in two majorsubdivisions: (A) blood vessels (arteries and arterialanastomoses important for collateral circulation,arterial anomalies, arterioles, veins, venules and
capillaries); and (B) central neural parenchyma (brainor spinal areas to which blood is supplied or fromwhich it is drained; peripheral and autonomic nervoussystems are not included).
The nomenclature of Nomina Anatomica (N.A.)1966 and the Standard Nomenclature of Diseases andOperations (S.N.) 1961 are used as much as possible.More detailed anatomy of some vessels and neuralstructures can be found in N.A., e.g., thalamus,hypothalamus, brain stem, cerebellum, cranial nerves,spinal cord. S.N. lists left or right side only for certainstructures. When these are of importance but notspecifically designated, the small-case letters 1. and r.will, in this Classification, indicate left and right,respectively. The small-case letter a. is used as an ab-breviation for artery, aa. for arteries, v. for vein, w.for veins, s. for venous sinus.
Although conventional anatomical subdivisionsare used as much as possible, practical considerationshave resulted in some exceptions, e.g., the subclavianartery is divided into three parts which are differentfrom the three or four parts of some anatomy texts.All known branches of a specific artery are not in-cluded in the Classification but only those consideredimportant in cerebrovascular and spinovascular dis-ease or those known to have important anastomoses.A strict order of arterial origin is not always followed,e.g., in the case of branches of the anterior cerebralartery. Arterial anastomoses are not separately listedbut may be described by indicating specific arterialsystems and branches involved.
Under "Brain and spinal cord," major sub-divisions of "Hemisphere" and "Brain stem" havebeen introduced, as these anatomical terms are com-monly used by clinicians and investigators workingwith cerebrovascular disease.
Part III. AnatomyA. Blood vessels
1. Arteriesa. Ascending aortab. Aortic arch
1) Brachiocephalic a. (innominate a.)2) Common carotid a. (specify r. or 1.)
a) External carotid a. (specify r. or 1.)(1) Superior thyroid a.(2) Lingual a.(3) Facial a. (external maxillary)(4) Occipital a.
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
5) Central white matter (specify by lobe)6) Internal capsule
a) Anterior limbb) Genuc) Posterior limb
7) Thalamus8) Inferior and medial hemisphere surfaces
a) Hippocampal gyrusb) Corpus callosumc) Other (specify)
9) Corpus striatuma) Caudate nucleusb) Lentiform nucleus
(1) Putamen(2) Globus pallidus
10) Hypothalamus11) Insula12) Other (specify)
b. Brain stem1) IYlidbrain
a) Tectumb) Tegmentumc) Cerebral peduncle
2) Ponsa) Tegmentumb) Basis
3) Medulla oblongataa) Dorsalb) Ventral
c. Cerebellum1) Vermis2) Cerebellar hemisphere3) Cerebellar nuclei4) Superior cerebellar peduncle5) Middle cerebellar peduncle
Part IV. Pathology
INTRODUCTION
Pathological alterations are considered in two majorsubdivisions: (A) blood vessels (arteries, arterioles,capillaries, venules, veins, and combined arterial,venous and capillary lesions); and (B) neuralparenchymatous lesions.
The etiological classification of the StandardNomenclature of Diseases and Operations (S.N.)1961 and the "Classification and Outline ofCerebrovascular Disease" (Neurology, Volume 8,
6) Inferior cerebellar peduncled. Cranial nerves
1) Olfactory n. (I)2) Optic n. (II)
a) Optic diskb) Prechiasmatic portionc) Optic chiasmd) Optic tract
3) Oculomotor n. (Ill)4) Trochlear n. (IV)5) Trigeminal n. (V)
a) Ophthalmic n.b) Maxillary n.c) Mandibular n.d) Gasserian ganglion
6) Abducens n. (VI)7) Facial n. (VII)8) Acoustic n. (VIII) (vestibulocochlear n.)
a) Cochlear divisionb) Vestibular division (labyrinthine division)
9) Glossopharyngeal n. (IX)10) Vagus n. (X)11) Accessory n. (XI) (spinal accessory n.)12) Hypoglossal n. (XII)
e. Cerebral ventricles1) Lateral ventricle (specify r. or 1.)2) Third ventricle
a) Choroid plexus3) Cerebral aqueduct (Sylvius)4) Fourth ventricle
Number 5, May 1958) are used whenever possible.Some additions, deletions and modifications havebeen made but the main portions of the Classificationcan be compared with the S.N. and the 1958Classification. In the sections concerned with lesionsof capillaries, the word petechiae is used since it con-notes hemorrhages which are small enough to berecognized as presumably of capillary origin, althoughsuch hemorrhagic lesions may also be of arteriolarand venular origin.
The World Federation of Neurology code forgrading atherosclerosis is in the Appendix.
Part IV. PathologyA. Pathological alterations in vessels
1. Arteries (and arterioles, when applicable)a. Congenital, developmental and inherited lesions
1) Absence of artery (aplasia)2) Hypoplasia of artery3) Anomaly of artery (fetal form)
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4) Anomaly of artery (unspecified)5) Redundancy (loops), dilatation, elongation; congenital, of artery6) Aneurysm, congenital
a) Ruptured, aneurysm, congenital7) Genetically determined defects in arteries
a) Marfan's syndrome (arachnodactyly)b) Ehlers-Danlos syndromec) Pseudoxanthoma elasticumd) Others
b. Inflammatory lesions (arteritides)1) Infectious arteritides
a) Septic embolismb) Syphilitic arteritisc) Pyogenic arteritisd) Tuberculous arteritise) Infectious arteritides of other types0 Complications of infectious arteritides
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
b) Rupture of atherosclerotic plaque(1) Atheromatous embolization
c) Thrombosisd) Embolization due to foreign materials (cotton fibers, etc.)
4) Trauma due to surgerya) Reconstructive and reparative arterial surgery
(1) Embolization by thrombotic fragments(2) Atheromatous or tissue embolization(3) Embolization due to foreign materials (cotton fibers, etc.)(4) Thrombosis(5) Thrombosis in arterial anastomosis(6) Thrombosis in arterial grafts
(a) Natural grafts(b) Synthetic grafts
(7) Aneurysm(8) Stenosis
b) Other surgical procedures(1) Occlusion (ligation, clamp, etc.)(2) Rupture or accidental division(3) Intramural hemorrhage
(a) With dissection(4) Rupture of atherosclerotic plaque
(a) Atheromatous embolization(5) Thrombosis
5) Trauma of artery due to brain herniation(transtentorial, subfalcial, foramen magnum, etc.)a) Thrombosisb) Hemorrhage
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
b) Sympathomimetic amines (specify)c) Heavy metals (arsenic, etc.; specify)
3) Calcificationa) Hypervitaminosis D
g. Arterial embolism due to cardiac disease and diseases of extracerebral vessels1) Cardiac arrhythmias (specify basic disease)2) Valvular disease (endocarditis)
a) Septic (specify)b) Aseptic (specify)
3) Myocardial infarction4) Atherosclerosis plus thrombosis5) Ulcerated atheroma6) Paradoxical embolism
a) Congenital heart diseaseb) Systemic venous thrombosis
(1) Aseptic(2) Septic
7) Pulmonary venous thrombosish. Arterial lesions associated with neoplastic disease
1) Thrombosis associated with neoplasm (specify)a) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
2) Hemorrhage associated with neoplasm (specify)a) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
3) Embolism associated with neoplasm (specify)a) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
i. Arterial lesions due to unknown causes1) Atherosclerosis
a) Atherosclerotic stenosis(1) Thrombosis
b) Atherosclerotic occlusion(1) Thrombosis
c) Ulceration of atherosclerotic plaque(1) Atheromatous embolization
d) Atherosclerotic dilatation, ectasia or aneurysm (fusiform)(1) With rupture
e) Atherosclerotic hemorrhage,f) Intramural hemorrhage in plaqueg) Calcification of atherosclerotic plaque
b) Remote effects(1) Fat embolization(2) Bone marrow embolization(3) Air embolization
2) Trauma due to angiographya) Intramural hemorrhage
(1) With dissectionb) Extramural hemorrhagec) Thrombosis
(1) With embolizationd) Embolization due to foreign materials (cotton fibers, etc.)
3) Trauma due to intravenous procedures, diagnostic and therapeutica) Intramural hemorrhageb) Extramural hemorrhagec) Thrombosis
(1) With embolizationd) Embolization due to foreign materials (cotton fibers, etc.)
4) Trauma due to surgerya) Surgery involving veins
(1) Embolization by thrombotic fragments(2) Tissue embolization(3) Embolization due to foreign materials (cotton fibers, etc.)(4) Thrombosis(5) Thrombosis in venous anastomosis(6) Thrombosis in venous grafts
(a) Natural grafts(b) Synthetic grafts
b) Other surgical procedures(1) Occlusion (ligation, clamp, etc.)(2) Rupture or accidental division(3) Intramural hemorrhage(4) Thrombosis
(a) With embolization5) Trauma of veins due to brain herniation (transtentorial, subfalcial, foramen magnum, etc.)
a) Thrombosisb) Hemorrhage
6) Radiation effects
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2) Hemorrhagea) Anticoagulants (specify)b) Heavy metals (specify)
3) Calcificationa) Hypervitaminosis D
g. Venous lesions associated with neoplastic disease1) Thrombosis associated with neoplasm (specify)
a) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
2) Hemorrhage associated with neoplasma) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
3) Embolism associated with neoplasm (specify)a) Intracranial neoplasm (primary or secondary)b) Extracranial neoplasm
h. Venous lesions due to unknown cause1) Phlebosclerosis2) Phlebolith3) Mineralization (ferrugination, calcification, siderocalcific change) in parenchymal vein (and
venules of CNS)a) Nonfamilialb) Familial calcification ("of basal ganglia")c) Other
4) Varix3. Capillaries
a. Inflammatory lesions1) Infectious capillary purpura2) Noninfectious capillary lesions
a) Thrombotic microangiopathy (thrombotic thrombopenia; TTP)b) Allergic capillary purpura
b. Trauma and physical agents1) External trauma
a) Petechiae2) Trauma by adjacent structures
a) Petechiae3) Remote effects of external trauma
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CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
a) Petechiae due to fat embolizationb) Petechiae due to bone marrow embolizationc) Petechiae due to air embolization
4) Trauma due to angiographya) Petechiae due to radiopaque contrast mediumb) Capillary thrombosis due to radiopaque contrast mediumc) Petechiae due to atheromatous embolizationd) Petechiae due to embolization by foreign materials (cotton fibers, etc.)
5) Trauma due to cardiac catheterization and other diagnostic and therapeutic intravascularproceduresa) Petechiae due to atheromatous embolizationb) Petechiae due to embolization by foreign materials (cotton fibers, etc.)
6) Trauma due to surgerya) Petechiae
7) Trauma of capillaries due to brain herniation (transtentorial, subfalcial, foramen magnum, etc.)a) Petechiae
8) Heat stroke (sunstroke)a) Petechiae with heat stroke
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
g. Capillary lesions associated with neoplastic disease1) Thrombosis associated with neoplasm [See II.A.8.]2) Petechiae (hemorrhage) [See H.A.8.]
h. Capillary lesions due to unknown cause1) Idiopathic brain purpura2) Mineralization (ferrugination, calcification, siderocalcific change) in capillaries of CNS
a) Nonfamilialb) Familial calcification ("of basal ganglia")c) Other
i. Capillary lesions associated with hypertension (specify type, etiology, or associated disease)1) Hyalinization and fibrosis of capillary
4. Combined arterial, venous and capillary abnormalitiesa. Congenital, developmental and inherited lesions
1) Arteriovenous fistula, congenital2) Arteriovenous fistula due to ruptured congenital aneurysm3) Vascular malformations (hamartomas, angiomas)
a) Telangiectasisb) Cavernous (venous) angioma (hemangioma)c) Arteriovenous angioma
4) Vascular malformations with the phakomatosesa) Lindau's diseaseb) Sturge-Weber's diseasec) Others
b. Inflammatory lesions1) Infectious
a) Arteriovenous aneurysm due to infectionb) Calcification of vessels due to congenital rubella
c. Trauma1) Trauma due to external forces, bony anomalies, fractures, dislocations, degenerative bone dis-
ease, fibrosisa) Arteriovenous fistula, traumatic
d. Metabolic abnormalities1) Avitaminosis (specify type)
e. Lesions due to unknown causes1) Arteriovenous fistula due to ruptures2) Arteriosclerotic aneurysm
B. Pathological alterations in brain1. Infarction (pale, hemorrhagic and mixed)
a. Without vessel stenosis or occlusionb. With arterial stenosis or occlusion due to:
1) Congenital, developmental and inherited lesions of arteries [See IV.A.I.a.]2) Inflammatory lesions of arteries [See IV.A.l.b.]3) Trauma and physical agents [See IV.A.I.e.]4) Blood dyscrasias [See IV.A.l.d.]5) Metabolic abnormalities [See IV.A.l.e.]6) Drugs, etc. [See IV.A.l.f.]7) Cardiac and extracerebral vessel disease [See IV.A.l.g.]8) Neoplastic disease [See IV.A.l.h.l9) Unknown causes (chiefly atherosclerosis) [See IV.A.l.i.]
10) Hypertension [See IV.A.l.j.]11) Other
c. With venous stenosis or occlusion due to:1) Congenital, developmental and inherited lesions [See IV.A.2.a.]2) Inflammatory lesions [See IV.A.2.b.]3) Trauma and physical agents [See IV.A.2.C.]4) Blood dyscrasias [See IV.A.2.d.]5) Metabolic abnormalities [See IV.A.2.e.]6) Drugs, etc. [See IV.A.2X]
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d. With capillary lesions [See IV.A.3.]e. With combined arterial, venous and capillary lesions [See IV.A.4.]Hemorrhage (intracranial, intracerebral, etc.)a. Without vessel type identifiedb. Of arterial origin
(list as under Pathological Alterations in vessels, or use anatomical and etiological terms as follows)1) Anatomical site
a) Intracerebral(1) With hypertension(2) Without hypertension
b) Subarachnoidc) Subdurald) Intraventricular
2) Etiologya) Congenital, developmental and inherited lesions of arteries [See I V.A.I.a.]b) Inflammatory lesions of arteries [See IV.A.l.b.]c) Trauma and physical agents [See IV.A.l.c]d) Blood dyscrasias [See IV.A.l.d.]e) Metabolic abnormalities [See IV.A.l.e.]f) Drugs, etc. [See IV.A.l.f.]g) Cardiac and extracerebral vessel disease [See IV.A.l.g.]h) Neoplastic disease [See IV.A.l.h.]i) Unknown causes [See IV.A.l.i.]j) Hypertension [See IV.A.l.j.]k) Other
c. Of venous origin1) Congenital, developmental and inherited lesions of arteries [See IV.A.2.a.]2) Inflammatory lesions [See IV.A.2.b.]3) Trauma and physical agents [See IV.A.2.C.]4) Blood dyscrasias [See IV.A.2.d.]5) Metabolic abnormalities [See IV.A.2.e.]6) Drugs, etc. [See IV.A.2.f.]7) Neoplastic disease [See IV.A.2.g.]8) Unknown causes [See IV.A.2.h.]
d. With capillary lesions [See IV.A.3.]e. With combined arterial, venous and capillary lesions [See IV.A.4.]
Part V. Clinical Phenomena (History,Physical Examination, Laboratory Ex-amination, Roentgen Examination,Other)INTRODUCTION
Part V (Clinical Phenomena) is designed to ac-complish classification or codification of materialfrom the patient's history, physical examination,laboratory examination and procedures which includeangiography, cerebral blood flow determinations andmany others. The physician caring for an individualpatient may not wish to formally use this portion ofthe Classification but may find it valuable as a form of"check list" or "reminder" concerning symptoms,physical signs and many laboratory and specialprocedures. Epidemiologists and clinical investigatorswill find special aid from Part V for assistance in con-
structing protocols and forms for systematicallyrecording clinical phenomena.
The subdivisions on Demography, FamilyHistory, and Past History are self-explanatory.
In using the subdivision "4. Present illness," it isimportant to refer to the definitions in Part I (ClinicalStage) — definitions which clearly describe the mean-ing of such categories as Transient Attacks (TIA) andActively Changing Neurological Deficit (progressingstroke). The definition of TIA includes comments con-cerning individual symptoms (i.e., vertigo, etc.) whichare not to be designated as TIA. Although the arterialsystem involved is classified under Part III(Anatomy), the anatomical site of TIA, etc., is also in-cluded in Part V as a convenience to the person usingthe Classification.
The first two categories of subdivision "B.
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Physical examination" are traditional ones: " 1 .General" and "2. Neurological." However, the thirdcategory "Vascular" includes much new materialwhich allows classification of the results of theneurovascular examination. In the "Outline" portionof the document is descriptive material concerningbruits, the findings from ophthalmoscopic examina-tion and the technique of ophthalmodynamometry.
The subdivision "C. Laboratory examination"contains many standard types of test. In the ap-propriate portion of the "Outline" are comments con-cerning the relative importance of many of these tests.Certain arbitrary decisions are necessary, i.e., placing"Echoencephalography" and "Brain scan" in thiscategory rather than under "E. Special procedures."
Because of the importance of cranial
angiography, a special subdivision "D. Roentgen ex-amination" is provided. Discussion of indications forangiography is included in the appropriate portion ofthe "Outline."
"E. Special procedures" provides a place forlisting a number of items which will be done only incenters where special clinical investigations ofcerebrovascular disease are done. Computerized axialtomography* (computerized tomography, computedtomography) is placed first; this appears to be an im-portant noninvasive technique for the differentialdiagnosis of cerebral infarction, intracerebralhemorrhage and intracranial neoplasm, and is becom-ing available in more and more localities.
*Commercial equipment: EMI scanner, ACTA scanner, etc.
Part V. Clinical Phenomena (History, Physical Examination, Laboratory Examina-tion, Roentgen Examination, Other)A. History
1. Demographica. Sexb. Age (specify date of birth) (day, month, year)c. Race, ethnic origin, and other related informationd. Occupation and/or socioeconomic statuse. Educationf. Environment (urban or rural)
2. Family historya. Cerebrovascular diseaseb. Hypertensionc. Diabetesd. Coronary artery diseasee. Other vascular diseasef. Other
1) Number (specify)2) Date of first attack3) Date of most recent attack4) Frequency
a) Becoming more frequentb) Becoming less frequentc) No change
5) Duration (describe)6) Precipitating factors
a) Position of body (describe)b) Change of position of head, neck or arm (describe)c) Exercise (describe)d) Hypotensione) Cardiac arrhythmia0 Emotiong) Other (specify)
7) Content of typical transient ischemic attack (symptoms)The following list of symptoms is not meant to be inclusive of all neurological phenomena. The listmay be used as a framework or check list. The content of a typical attack or of several attacks mayneed to be described in narrative form and an indication of sequence of occurrence of several symp-toms and of their severity may need to be indicated (specify site, type and degree). These items will beapplicable for all subsequent categories of clinical stage.a) Impaired consciousnessb) Confusionc) Amnesiad) Visual disturbance
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
(1) Focal(2) Generalized
r) Other8) Arterial system
a) Carotidb) Vertebrobasilarc) Mixedd) Uncertain
b. Actively changing neurological deficit (progressing stroke)1) Time of onset (specify date and hour)2) Duration of change (progression) (specify time)3) Predisposing factors [See II.E.]4) Precipitating factors [See V.A.4.a.6)]5) Symptoms [See V.A.4.a.7)]6) Arterial system
c. Prolonged neurological deficit (reversible ischemic neurological deficit [RIND] and completed stroke)Please make a distinction between RIND and long course as defined in I.B.3.1) Time of onset (specify date and number of minutes or hours from first symptom to maximum
d. Blood pressure Left RightPostural change (specify)
e. Cardiac status (describe if abnormal)f. Bowel status (describe if abnormal)g. Bladder status (describe if abnormal)
2. Neurologicala. State of consciousness (It is recognized that there are many ways of describing this item. It is important
that the user of this Classification construct a standard system of description of state of consciousness,such as:)1) Normal2) Semi-stupor (lethargy — response slowed)3) Stupor (appropriate response to verbal stimulus)4) Deep stupor (purposeful response to noxious stimulus)5) Semicoma (nonspecific response to pain)6) Coma (above reflexes present — no response to pain)7) Deep coma (absent DTRs, pupillary reactions and corneal reflexes — no response to pain)
b. Mental function1) Normal2) Impairment of intellect
a) Memoryb) Recallc) Calculation
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a) Bicepsb) Tricepsc) Brachioradialisd) Hoffmanne) Kneef) Hamstringg) Ankleh) Other
2) Cutaneousa) Abdominalb) Other
3) Miscellaneousa) Plantar (Babinski)b) Graspc) Snoutd) Suckinge) Other
f. Motor function1) Gait (describe)2) Posture (describe)3) Strength (grade each muscle if appropriate)
a) Normalb) Mild impairment of strength (fair). Full range of motion against resistancec) Moderate impairment of strength (poor). Full range of motion antigravityd) Severe impairment of strength (combine polio classification "trace" and "poor"). Full range of
motion with gravity eliminatede) No strength
4) Coordination (limb)a) Ataxia (faulty synergistic action throughout movement)b) Dysmetria (faulty in measuring to the object)c) Rebound phenomena
5) Praxis and alternate motion rate (AMR) (describe)6) Adventitious movements (describe)7) Other phenomena disturbing motor function (describe)
a) Contracturesb) Muscle tone
8) Evaluation of the function of groups of musclesa) Upper extremity (patient sitting)
(1) Normal (4+) (No impairment of function)(2) Good (3+) (Mild impairment of function) Normal except for skilled acts and endurance(3) Fair (2+) (Moderate impairment of function) Shoulder abduction and extension of elbow +
grasp and release of hand + supination-pronation of forearm through full range of motionbut with impaired speed, coordination and strength
(4) Poor (1+) (Severe impairment of function) Has shoulder abduction and extension but notthrough full range of motion
(5) Bad (0) (No function)b) Lower extremity
(1) Normal(2) Mild impairment of function
(a) Knee extension normal(b) Hip and knee flexion good(c) Dorsiflexion of ankle poor(d) Walks well — lacks full skill and endurance
(3) Moderate impairment of function(a) Knee extension present(b) Knee and hip flexion poor(c) Dorsiflexion of ankle out(d) Walks — much trouble
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e. Ophthalmodynamometry (record as listed) [See Outline]1) Position of patient
a) Sitting .b) Lying.c) Standing-
2) Value (systolic/diastolic)a) Rightb) Left
f. Neurological signs produced by position1) Head turning2) Standing up3) Sitting up
g. Veins (specify pertinent abnormalities)
•The value of carotid compression tests relative to the information gained compared to the risk to the patient limits the use of the test tolaboratories where careful monitoring of the patient (with ECG, EEG, etc.) is possible.
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C. Laboratory examination1. Urinalysis (specify abnormality)2. Blood
Hemoglobin, red blood count, white blood count, hematocrit, viscosity, volume, cholesterol, lipids, serumenzymes, sugar, blood urea nitrogen, uric acid, creatinine, sedimentation rate, coagulation studies, plateletcount, total thyroxine, serologic test for syphilis, L. E. cell preparation
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
Part VI . Status of Patient (Performanceand Placement)INTRODUCTION
At many points in the natural history of stroke, it isdesirable to estimate the performance ability of thepatient. In this section, a classification of performanceability and placement potential is presented. Suchassessment of the status of the patient serves as asignificant guide to the course the disease process hastaken, the management effort required, and the selec-tion of a life-situation to which the patient can ap-propriately return. Ability of the patient to performsatisfying and productive activity in a supportive en-vironment is a resultant of many intrinsic and extrin-sic factors. Intrinsic factors may include suchelements as the degree of general and focal cerebraldamage, the residual neurological function, the in-tegration of adaptive and substitute patterns of func-tion, the pre-existing level of development of intellectand skill, and developed attitudes and emotions. Ex-trinsic factors are even more varied and numerous andinclude such influences as the nature of the physicalenvironment and living arrangements, the degree offamily involvement and support, interpersonalrelationships, the social and economic resources, andeven attitudes of the family, friends, potentialemployers and the community at large. Prescriptionfor continuing management in and outside of thehealth care facility must be based on informationderived in detail from all available clinical and socialsources. Classification of performance and placementprovides a gross characterization of what life-tasks thepatient is able to do and how he will be able to live.
PERFORMANCE
In the context used in this Classification, performanceis defined as the execution of set tasks. The design of atask can be structured in formal testing or can bevariably determined by environmental or situationalcircumstances of the life-setting. The nature of thetask determines the action to be taken by the patient.The patient must be able to recognize the demandsmade on him by the task, to select the appropriate ac-tion to accomplish the task and then to successfullycarry out the selected action. Because the broad rangeof life-situations sets innumerable variations of taskrequirement, only generally recognized descriptions ofperformance that are of key significance in the care ofthe stroke patient form the basis of this Classification.It is further recognized that performance in a test set-ting varies according to test conditions and socialsituations and may not necessarily predict perfor-mance in other social contexts such as in the house, atwork, or in the community at large. These con-siderations color but do not negate the value ofclassification by test and observation.
For purposes of this Classification, three descrip-tors of life-situations are selected as indices of perfor-mance status. These are: (a) activities of daily living
(ADL), (b) avocational activities, and (c) occupationalactivities.
Activities of daily living (ADL) — a battery oftasks designed to provide an index of ability toperform self-sustaining activities that meet personal re-quirements in each day's life-experience. These essen-tial activities are basic in everyone's day, relatively in-dependent of geographic locale, physical environment,or .social situation. They include such common ac-tivities as dressing, washing, eating and traveling fromplace to place; they involve fundamental actions ofbody and limb movement, sitting balance, changingbody position, standing, reaching, grasping, holding,and the like.
Avocational activities — those active pursuits ofliving not directly related to one's primary life workfrom which the individual gains significant par-ticipatory, creative or productive satisfaction. Theseare not essential requirements of everyday living buthave value in bringing purpose and fulfillment to theindividual, his family and circle of friends. They in-volve multifaceted behavior patterns and at timesemploy complex hierarchies of physical and mentalactivities. Avocational activities include such pursuitsas hobbies, travel, recreation, socializing and the like.
Occupation — the primary life-work to which theindividual devotes the major portion of time, skill,energy, thought and effort and from which the in-dividual derives role and status, physical and mentalsatisfaction and economic support. In addition torecognized modes of remunerative employment, oc-cupation includes homemaking, student life, retire-ment and other primary life-pursuits. In thisClassification all such pursuits engaged in at the timeof onset of stroke are considered the primary occu-pation.
PLACEMENT
The goal of care is ultimate return of the recoveredpatient to an optimal physical, mental, social,vocational and economic condition consistent with thepatient's remaining performance abilities and re-quirements for continued health maintenance.Suitable physical environment, living arrangements,and social, economic and health care support must beselected. Medical status, performance ability and con-ditions in available environmental settings arevariables that determine the placement status. Amongthe critical considerations leading to optimal place-ment are the suitability of the architecture and sur-rounding environment, the kind and frequency of per-sonal supervision and direction required, and the levelof requirement for continuing medical-nursing care.Possibilities for placement vary widely but may in-clude placement in full competitive employment,placement in sheltered or selected work situations,resumption of homemaker duties, retirement from thework market, independent living in personal residencewith full management responsibility, home care with
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family supervision, home care with outside assistance,domiciliary care, convalescent care, custodial care, orcontinued rehabilitation center or hospital care.
Part VI. Status of Patient (Performanceand Placement)PERFORMANCE
Class I. No Significant Impairment — fullyindependent acts of daily living (ADL), pursues usualavocational activities, and returns to previous livingsite and occupation without modification.
Class II. Mildly Impaired — semidependent (re-quiring some assistance) in activities of daily living,and/or slight restriction of avocational activities,and/or able to return to previous occupation withsome modification of the latter.
Class III. Moderately Impaired — semidepen-dent (requiring lifting assistance) in activities of dailyliving, and/or considerable restriction of avocational
activities, and/or unable to return to previous occupa-tion and must seek selective occupation.
Class IV. Severely Impaired — fully dependent inconduct of activities of daily living, and/or unable toparticipate in avocational activities, and/or unable tocarry out any occupation.
PLACEMENT
Class A. No Limitation.Class B. Mild Limitation — requires occasional
supervision, and/or modified environment and/or oc-casional medical care.
Class C. Moderate Limitation — requires muchsupervision, and/or physical assistance or outsidehelpers and/or regularly available medical care.
Class D. Severe Limitation — requires constantor nearly constant attendance and/or immediatelyavailable medical-nursing care.(Continued on p 594)
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Outline of Cerebrovascular DiseasesVascular disorders affecting the brain have a variety ofcomponents:
1. The basic pathophysiological process whichconsists of: decreased perfusion pressure because of acardiac or systemic circulatory problem, abnor-malities of the blood (polycythemia, etc.) or abnor-malities directly impairing the vessel's transport ofblood (atherosclerosis, embolism, thrombosis,arteritis, etc.), singly or in a variety of combinations.As a result of these processes, the metabolic substratefor normal brain function is not supplied.
2. The pathophysiological change in brainparenchyma metabolism (commonly focal) which maybe of short duration (as in a transient focal cerebralischemic attack) and reversible, or may be infarction ifimpaired circulation persists, or may be hemorrhage ifa vessel ruptures.
3. The neurological abnormality which resultsfrom the focal deficit in brain metabolism. The tem-poral profile of the neurological abnormality variesgreatly — from a brief event (TIA) to permanentsevere brain damage (completed stroke) producinghemiplegia, etc., or death.
The "Outline" is to assist all health professionals;it deals with the problems posed by individual patientsand thus starts with "Clinical Stage." The "Outline"contains a full definition of each category under"Clinical Stage" as well as mixing concepts from"Pathophysiological Mechanisms," "Anatomy" and"Pathology" just as the physician must simulta-neously mix these concepts as he attempts to solve thediagnostic and treatment dilemma presented by a pa-tient.
OutlinePart I. Clinical StageThe primary purpose of this section of theClassification is to provide a framework for thedescription of the current status of the patient inreference to the temporal profile of the disease withoutregard to other factors, such as etiology, pathology,neural deficit and the like, all of which are described inseparate sections.
As the condition of the patient may be changing,sometimes rapidly, a static description presents cer-tain problems, particularly as to the exact time when apatient is categorized. In general, a patient is placedinto one of the categories at the time he is studied insufficient detail so as to permit a reasonably certainclinical diagnosis. Because of the evolution of thedeficit, it is likely that a patient will be in differentcategories at different times; in these instances a state-ment must be made to indicate the time of categoriza-tion. It is possible, also, that some deficits will bestable while other deficits are evolving; in these in-stances, appropriate comments will need to be made.By using more than one category, an accurate descrip-
tion of a complex temporal profile can be built (e.g., apatient who has TIAs followed by a completed strokewith a permanent residual neurological deficit andsubsequently again has TIAs would be classified asI.B.I., I.B.3., and later I.B.I.).
It is obvious that an infinite number of variationscan be discerned among the patterns of cere-brovascular disease; thus any classification is some-what arbitrary. Furthermore, the purist may notesome mixing of clinical description with pathologicalentities. The Committee recognized that the rate ofchange might be important but to describe this fullywould lead to too complex a classification.
A. AsymptomaticThis category is for cerebrally asymptomatic in-
dividuals who are found to have evidence which maypotentially be important as predisposing to futurecerebrovascular disease. Such evidence is listed indetail in Part II. Some of the factors in this evidencehave been termed the "Stroke Prone Profile."
B. Focal cerebral dysfunctionThis category refers to focal brain dysfunction
regardless of the nature of the vascular pathology(e.g., ischemic disease, intracranial hemorrhage,arteritis).*
1. Transient ischemic attacksThese are episodes of temporary and focal
cerebral dysfunction of vascular origin, rapid in onset(no symptoms to maximal symptoms in less than fiveminutes and usually less than a minute), which arevariable in duration, commonly lasting from 2 to 15minutes but occasionally lasting as long as a day (24hours). The resolution or disappearance of eachepisode is swift (ordinarily a few minutes at most). Aprolonged attack may take longer to clear. Each at-tack leaves no persistent neurological deficit. It iscommon practice to define these events as related tothe carotid arterial system or the vertebrobasilararterial system, meaning that the clinical locus ofischemia is in the customary distribution of one or theother of these arterial systems. There may be only oneattack or there may be multiple attacks at varying in-tervals. One must recall that there are unusual in-stances which fall outside of this standard definition.This definition is constructed in arbitrary fashion in anattempt to provide a common basis for collectinggroups of TIA patients. The contents of TIA arecoded under Part V. Clinical Phenomena, 4. Presentillness, a. Transient attacks.
•Migraine syndrome. The aura of migraine (e.g., scintillatingscotoma) is commonly attributed to focal cerebral ischemia owingto vasoconstriction. In some instances more severe neurologicaldeficits precede the headache and may include hemiparesis,dysphasia and homonymous hemianopia and in the great majorityof instances these deficits are transitory, only rarely persisting longenough to produce a cerebral infarct. The temporal profile may beclassified under "Clinical Stage" while the word "migraine" is un-der II.A.5.b.
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The typical history for a TIA in the carotidsystem is a swift (no symptoms to maximal symptomsin less than five minutes, usually less than twominutes) onset of:
1. Motor defect (weakness, paralysis, poor use,or clumsiness of one extremity or of both extremitieson the same side).
2. Sensory defect (numbness including loss ofsensation or paresthesias involving one or both ex-tremities on the same side).
3. Aphasia (speech and/or language disturbancewhich may be only a minor defect or may be globaland may or may not include difficulty in reading,writing, or performing calculations).
4. Loss of vision in one eye or in part of one eyewhen vision in both eyes was intact (amaurosis fugax).
5. Homonymous hemianopia.6. Combinations of the above.These clinical phenomena generally represent a
decrease or absence of function. When there is a sen-sory event, it is commonly described as coming on allat once, that is, without a march.
The typical history of a TIA in the vertebro-basilar arterial system is a swift (no symptoms tomaximum symptoms in less than five minutes, usuallyless than two minutes) onset of:
1. Motor defect (weakness, clumsiness, orparalysis of any combination of extremities up toquadriplegia, sometimes changing from one side toanother in different attacks).
2. Sensory defect (numbness, including loss ofsensation or paresthesias in any combination of ex-tremities including all four or involving both sides ofthe face or mouth. This is frequently bilateral troubleor the distribution may change from side to side indifferent attacks).
3. Loss of vision, complete or partial in bothhomonymous fields (bilateral homonymous hemi-anopia).
4. Homonymous hemianopia.5. Ataxia, imbalance, unsteadiness, or dysequi-
librium not associated with vertigo.6. Either vertigo (with or without nausea and
vomiting), diplopia, dysphagia, or dysarthria is not tobe considered as a TIA when any of these symptomsoccurs alone, but in combination with one another orwith any of the above (numbers 1, 2, 3 and 4) the at-tacks should be considered a TIA.
7. Combinations of the above.These clinical phenomena generally represent a
decrease or absence of function. At times, the motor,sensory or visual defect constituting the content of avertebrobasilar attack will be unilateral. It becomesdifficult in such instances to make a distinctionbetween whether the locus of ischemia is in the carotidarterial system or in the vertebrobasilar arterialsystem. In the list above, "drop attacks" is omitted.Fainting (syncope) is frequently confused with a "dropattack," so the latter should be included in the
vertebrobasilar profile only when the patient's descrip-tion of the "drop attack" is absolutely clear. Thevariety of manifestations included in the vertebro-basilar profile makes the potential pattern of symp-toms considerably more variable and complex thanthat in the carotid system.
The diagnosis of TIA rests on the history of theattacks; the skill with which the history is taken andthe interpretation of the history, except for thoserelatively few instances where the physician is with thepatient at the time of the attack. The criteria for mak-ing the diagnosis will vary depending on whether anindividual physician is working with an individualpatient or whether the purpose is the screening of apopulation for TIAs. A problem is created, as in muchof medical diagnosis, because of the relative weight orsignificance of some historical phenomena comparedto other phenomena. The symptom "numbness"(mentioned above) is an example. If the question is,"Have you ever had a numb hand?," the answer frommost adults will be "yes." This question is almostcompletely non-selective (non-diagnostic) and must befollowed by a series of questions to establish the mean-ing and significance of the "numbness." In contrast,another phenomenon, when present, is simple andrelatively much more significant than "numbness;"i.e., "Have you ever had painless blindness in one eyewhich came on very quickly (seconds) and lasted onlya few minutes (5 to 20)?" is a question which, ifanswered "yes," is reasonably specific. Anothersimilar but less specific question is "Have you everhad the sudden onset of a 5 to 20-minute duration at-tack of severe weakness of one side of the body (armand leg)?" Another is "Have you ever suddenly lostthe ability to speak (5 to 20 minutes' duration) or tounderstand the speech of others?" These questions il-lustrate the importance of understanding that differentquestions may have relatively different complexity andimportance.
The matter of relative significance of differentsymptoms is important in the vertebrobasilar systemas it is in the carotid system. For instance, if one asksthe question, "Have you ever had any dizziness?,"almost all adults will answer "yes." This question isalmost completely non-selective (non-diagnostic) andif answered affirmatively must be followed by a seriesof direct and branching questions to establish themeaning and significance of the original phenomenon— "dizziness." A diagnosis of a TIA in the vertebro-basilar system should not be made on the basis of ahistory of a few minutes of vertigo as the only symp-tom. This is emphasized since vertigo is the most com-mon symptom in the vertebrobasilar system; how-ever, a diagnosis of vertebrobasilar TIA is made onlywhen there is concurrently with vertigo (dizziness) anadditional symptom or symptoms.
In some instances, patients with carotid systemTIAs may have physical signs of appropriate arterialdisease. These include diminished pulsation in the
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carotid artery, a bruit over the carotid artery or eye,emboli in the retinal vessels, or other signs of ischemicretinopathy and relative hypotension in the retinalartery as measured with the ophthalmodynamometer.These are only signs of arterial disease and may bepresent in the absence of a history of TIAs. In certaininstances, bruits signifying compromise of flow in theinnominate artery, either subclavian artery, or at theorigin of either vertebral artery may be present;however, the absence or presence of such sounds doesnot weigh heavily in the diagnosis of vertebrobasilarTIA since it is again emphasized that the diagnosis isdependent upon the history of the attack, not uponmorphological evidence of change in patterns of bloodflow.
Certain symptoms may appear in a TIA in eitherarterial system. The most important of these are:
1. Dysarthria, if it occurs alone, and2. Homonymous hemianopia, if it occurs alone.The occurrence of certain symptoms in solitary
fashion constitutes an attack which is an "uncertainTIA." An attack which consists solely of each of thefollowing symptoms should be categorized as an un-certain TIA:
For the sake of clarity, the following symptoms, tran-sient or prolonged, are not to be included as TIA:
1. Unconsciousness including syncope2. Tonic and/or clonic activity3. March of a sensory defect4. Vertigo alone5. Dysphagia alone6. Dysarthria alone7. Incontinence of bowel or bladder8. Dizziness or wooziness alone9. Loss of vision associated with alteration of
consciousness10. Focal symptoms associated with migraine11. Scintillating scotomata12. Confusion alone13. Amnesia aloneThe differential diagnosis of TIAs includes
"hemiplegic" migraine, focal convulsive events (oftendue to neoplasm and producing either sensory ormotor phenomena), Meniere's disorder, sensoryphenomena associated with hyperventilation, andfinally some unknown mechanism. The differentiationof "hemiplegic" migraine is a semantic and practicalproblem. In those instances where the aura ofmigraine is associated with a definitely focalneurological event, the latter may well be the result oftransient focal cerebral ischemia but the implicationsare different than the usual TIA. To establish adiagnosis of the migraine association, there is or-dinarily a positive family history, characteristic uni-lateral headache with nausea and sometimes vomiting,
and onset of the attacks several decades ahead of theage at which TIAs commonly begin. Very carefulhistory-taking ordinarily delineates the transient focalevents associated with brain neoplasm from TIAs andthis is also true of the other items in the differentialdiagnosis.
Many factors might be included to describe thecharacteristics of the change or rate of change in eachindividual attack or the pattern in many attacks.These factors are dealt with in I.B.2.
2. Actively changing neurological deficitThis category refers to a patient whose
neurological deficit is actively changing in amountduring the period of observation (specify durationfrom time of onset). The deficit may be getting moresevere or less severe.
a. Improvingb. Worsening (also known as "progressing
stroke" or "stroke-in-evolution")This category represents the common cir-
cumstance where focal ischemia is worsening and theprocess of infarction is beginning or extending. (In un-usual instances slow onset bleeding may produce asimilar temporal profile.) This subdivision is dividedinto those situations where the focal pathology is inthe characteristic territory supplied by the carotidarterial system and where the supply is through thevertebrobasilar arterial system. As mentioned earlier,because of the evolution of the deficit, it is likely thatpatients will be in different categories at differenttimes. For instance, a patient seen at 10 A.M. with mildleft upper extremity weakness (history of onset at 9A.M. the same day), re-examined at 11 A.M. and foundto have paralysis of that extremity, would be classifiedas "progressing stroke," but if the deficit had dis-appeared at 11 A.M., the categorization would be"transient ischemic attack."
Description of the neurological findings mostoften characteristic of a focal deficit in specific arterialterritories will be found under Part V.B.2.
This category refers to a relatively stableneurological deficit, that is, during the period of obser-vation for categorization (specify duration from timeof onset), little or no change in the deficit is occurring.
a. Duration more than 24 hours — less thanthree weeks (sometimes referred to as a reversibleischemic neurological deficit or RIND).
b. Duration more than three weeks — often per-manent (commonly known as "completed stroke").
THROMBOTIC INFARCTION
Thrombotic infarction is divided into those situa-tions where there is infarction in the characteristicterritory supplied by the carotid arterial system orwhere the supply is through the vertebrobasilararterial system. Those infarctions occurring in thecarotid arterial distribution often come on rather
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abruptly over a matter of many minutes to a very fewhours. The neurological deficit may become maximumduring sleep and, therefore, may be maximum whenfirst discovered or may require several hours to aday to evolve. In a significant percentage of cases,there will have been warning TIAs. While theremay be some head discomfort, violent headache israre. There is relative preservation of consciousnessand at times there may be rapid improvement. Thecerebrospinal fluid (CSF) commonly remains clearand there is often associated evidence ofatherosclerosis elsewhere in the coronary andperipheral vessels. The clinician searches for thepresence of disorders commonly associated withatherosclerosis (hypertension, diabetes mellitus, gout,various forms of heart disease and xanthomatosis).The neurological examination reveals weakness ornumbness limited to one side of the body. If the domi-nant hemisphere is involved, there may be aphasia or,which is more common, a dysphasia which will vary asfar as its precise content is concerned. It is interestingto note that in this type of "stroke" the visual fielddefects will generally be homonymous, and it is rarefor there to be simultaneous evidence of complete uni-lateral retinal ischemia and focal brain ischemia onthe same side. As a clinician looks at the temporalprofile of the disorder, he must attempt to decidewhether the cerebral infarction is still progressing, asevidenced by, an increasing neurological deficit, orwhether the "stroke" is essentially completed, mean-ing that there is no further progression of theneurological deficit. This decision can be made only byrelating the history of the preceding few minutes orhours to the existing findings or by picking up the tem-poral profile at the point where the patient is first seenand carefully re-examining the situation every fewminutes or hours.
As in TIAs there may be, with the overt evidenceof a focal neurological defect, signs which suggestgeneral or local vascular disease. Hypertension andvarious forms of cardiac abnormality relate to theformer, while bruits over the carotid bifurcation,retinal emboli, other evidence of ischemic retinopathyand a unilateral decrease of retinal artery pressuredemonstrated by the use of the ophthalmo-dynamometer exemplify the latter. The differenti-ation of thrombosis in the vertebrobasilar system fromintracerebral hemorrhage is not difficult, but there is asignificant problem concerning the differentialdiagnosis of thrombosis in the carotid system and in-tracerebral hemorrhage. Table 1 lists the principaldifferences.
INTRACEREBRAL HEMORRHAGE
The absence of a history of TIAs is mentioned firstsince, if a history of such episodes is obtained, thediagnosis of intracerebral hemorrhage is almosteliminated from differential consideration. Symptomsassociated with intracerebral hemorrhage generally
TAILI1
Differences Between Clinical Picture of Cerebral Infarc-tion and Intracerebral Hemorrhage
Infarct lntrac«r«bral h«morrhag*
Often TIAOften onset at restMinimal cranial discomfort
(often none)Focal neurological deficit
without change inconsciousness. Oftenparalysis of a functionwith normal mentation
Moderate HBP(occasionallynormotensive)
Clear CSF
No TIAOnset during activityHeadache (sometimes
severe)Rapidly changing
neurological deficitincluding state ofconsciousnessalternating to coma
Severe HBP (occasionallymoderatehypertension)
Bloody CSF
TIA = transient ischemic attack, HBPCSF = cerebrospinal fluid.
high blood pressure,
come on during activity, and if the patient issufficiently conscious to report his symptoms, the ex-istence of head discomfort (sometimes described asvery severe headache) is commonly related. There is arapid evolution of focal neurological phenomena overmany minutes or a few hours with hemiplegia beingthe most frequently observed neurological deficit. Thisrapid evolution, unfortunately, progresses to a statewhere there is involvement of consciousness going onquickly to coma. It is uncommon for a discreteparalysis of a function with normal mentation to bethe physical picture. Usually the blood pressure ismarkedly elevated; in infrequent instances there maybe only moderate hypertension. In 75% to 85% ofpatients with intracerebral hemorrhage, there will begrossly bloody CSF.
CEREBRAL INFARCTION SECONDARY TO EMBOLIC ARTERIALOCCLUSION (CARDIAC SOURCE)
It is now important to make the distinction betweenan embolus which comes from a relatively distantsource, such as the heart or lungs, and the embolus oremboli which originate in an artery to the brain suchas the carotid, vertebral or basilar arteries. This dis-cussion has to do with the traditional source of em-bolus, principally the heart.
The most characteristic component of the clinicalpicture of cerebral infarction secondary to embolicarterial occlusion (cardiac source) is the extraor-dinarily sudden development of focal neurologicalsymptoms and signs. The patient is often struck downwithin seconds or at most a few minutes, meaning thatthere is progression to maximum neurological deficitin this very swift fashion. Frequently there is no com-plaint of pain along with the relative preservation ofnormal consciousness. There is an absence of historyof antecedent TIAs, ordinarily a clear CSF, and,generally, a discrete and clearly focal neurological
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constellation of physical abnormalities. Most impor-tant to this diagnosis is the demonstration of a sourceof emboli, usually in the heart. This "source" com-monly consists of either a cardiac arrhythmia,valvular heart disease, or myocardial infarction. In aminority of instances, the basic pathology may be sub-acute bacterial endocarditis. Concurrent with thesearch for a source of emboli is the search for evidenceof recent embolism in other organs: spleen, kidney,lungs or extremities. Usually, the CSF is clear. Rapidimprovement may take place.
CEREBRAL INFARCTION SECONDARY TO EMBOLIC ARTERIALOCCLUSION (EMBOLI FROM AN INTRA-ARTERIAL SOURCE)
When emboli consist of thrombus which has formedon an atherosclerotic plaque or of material from an ul-cerated atherosclerotic plaque, the source is called"intra-arterial." The temporal profile of the clinicalevents may be variable from quite swift (many secondsto a few minutes) to hours. Particularly in the carotidsystem, a history of previous attacks of amaurosisfugax with or without transient focal cerebral ischemicattacks favors an embolic cause, while a loud longsystolic or systolic-diastolic carotid bifurcation bruit,cholesterol retinal emboli or ipsilateral decrease inretinal arterial pressure is important evidence for thecarotid origin of emboli.
"PRIMARY" SUBARACHNOID HEMORRHAGE
This term refers to a situation where initially thebleeding occurs directly into the subarachnoid spaceand thus a distinction is made between this disorderand the condition subtending when an intracerebralhemorrhage breaks either into the subarachnoid spaceor into a ventricle.
The characteristic clinical picture of "primary"subarachnoid hemorrhage begins with the extraor-dinarily sudden onset of severe headache. These twoitems, the suddenness of onset and the severity of pain,are commonly dramatic. The suddenness means a sec-ond or two of time to a minute and the headache is im-mediately so intense that it alters the pattern of thepatient's activity. In some instances, there is an im-mediate or almost immediate disturbance of con-sciousness (including unconsciousness with recoveryof consciousness in a few minutes). Often there isabsence or a poverty of definite focal neurologicalsigns. The somewhat frequent exception to this is theappearance of a partial oculomotor nerve palsy. In afew minutes there is commonly nausea and may bevomiting. The patient may complain of a stiff neck orextension of the cranial discomfort into the posteriorcervical region. On physical examination, particularlyif the patient is not in extremis, there is a stiff neck onforward bending and there may be Kernig's or Brud-zinski's signs as evidence of meningeal irritation.Subhyaloid (pre-retinal) hemorrhages may bedetected within a few minutes of onset of the symp-
toms. Mandatory to the diagnosis is the presence ofgross bleeding into the CSF. The clinical diagnosiscannot be substantiated without this finding. Theprecise source of the bleeding, as well as the genesis ofthe defect in the arterial wall, often are not predictedaccurately on the basis of clinical examination.Subsequent arteriography has demonstrated that themost common defect is the rupture of a saccularaneurysm but in some situations there is noarteriographic evidence of any abnormality. Rarely, aneoplasm may be the source of bleeding but with thewhole clinical picture the differential diagnosis can bemade with a high degree of accuracy. If there are ahistory of previous convulsive phenomena, a patient inthe second, third or fourth decades of life, a cranialbruit, and particularly a characteristic calcificationwhich appears in x-rays of the head, the existence ofan arteriovenous malformation is likely.
INTRACRANIAL HEMORRHAGE FROM A VASCULAR MALFORMATION
While subarachnoid hemorrhage results from a defectin the wall of an intracranial vascular malformationand the onset of symptoms may be sudden, there isseldom the drama of swiftness and severity commonlyassociated with subarachnoid hemorrhage from othersources.
As mentioned above, there is generally a historyof preceding convulsive phenomena and in some in-stances there is a story of focal cerebral symptoms.When subarachnoid bleeding with a mild focalneurological deficit and gross blood in the CSF is thesequence of events in an individual in the second, thirdor fourth decades, the rupture of an intracranialarteriovenous malformation should be suspected. In20% to 25% of instances, a cranial bruit is present.Some subhyaloid (pre-retinal) hemorrhages maydevelop, and particular attention is paid to the detec-tion of retinal angiomas since vascular malformationsmay occur in multiple sites (the retina as well as thebrain). X-rays of the head may show calcification,which sometimes is characteristic evidence for thepresence of an arteriovenous abnormality. As impliedabove, the CSF contains gross blood which is not dueto a "mechanically bloody cerebrospinal fluid tap"and the observation of blood in the spinal fluid sec-ondary to an intracranial or intraspinal pathologywhich has produced the bleeding.
EXTRADURAL AND SUBDURAL HEMORRHAGE
Intracranial bleeding due to head trauma is notordinarily thought of as a "stroke." However, it is in-cluded here because of the frequency with which thequestion of diagnosis of traumatic intracerebralhemorrhage arises in instances where the history is in-adequate or where the patient has fallen and injuredhimself at the time of onset of the "stroke." Acute ex-tradural and subdural hemorrhage must always beconsidered in the patient who has had any kind of head
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injury or an abrupt ictus under known circumstances,whether the spinal fluid is bloody or clear.
It is particularly important that acute in-tracerebellar hemorrhage be considered in thedifferential diagnosis when there is sudden onset of asevere focal cerebellar deficit with progression whichoften includes nausea and vomiting, cranial nervepalsies, drowsiness and subsequent further change inconsciousness. Appropriate neurosurgical treatmentmay be lifesaving.
Chronic subdural hemorrhage may occur withouta history of trauma, and the clinical picture ofheadache with some drowsiness, mental confusion andoccasionally mild focal neurological deficit, especiallyin the elderly, may be incorrectly diagnosed ascerebral infarction. Acute extradural hemorrhage,acute subdural hemorrhage, and chronic subduralhematoma must be thought of constantly; thereshould be no hesitation in proceeding to placediagnostic burr holes in instances where subduralbleeding cannot be appropriately excluded.
OTHER CAUSES OF INTRACRANIAL HEMORRHAGE
Hematological disorders which may give rise tointracranial bleeding are leukemia, aplastic anemiaand thrombocytopenic purpura. Any portion of thebrain may be involved and frequently the lesions aremultiple. When cerebral hemorrhage occurs, there isoften evidence of previous abnormal bleedingelsewhere in the body (skin, mucous membrane,kidney, or bowel). Rarely, an intracerebralhemorrhage may be associated with chronic liver dis-ease and intracranial bleeding is a rare complicationof anticoagulant therapy.
Brain stem hemorrhage secondary to herniationof a portion of the temporal lobe through the tentorialnotch is all too frequent a complication of an expand-ing supratentorial lesion such as neoplasm, abscess,primary intracerebral hemorrhage or massive cerebralinfarction. This type of hemorrhage is in the midbrainand pons, and constitutes a serious complication oftemporal lobe herniation, almost always resulting inirreversible coma and death. These hemorrhages aregiven the name of Duret, who was one of the firstworkers to observe and describe them.
Hemorrhage into primary and secondary braintumors is an uncommon complication of these lesions.In rare instances, the first clinical phenomenonproduced by the basic pathological lesion will be thesudden occurrence of a focal neurological deficit. Inthese unusual instances, the clinical picture is that of astroke. In some situations, the clue that the bleeding issecondary and not primary is provided either by theknown presence of neoplastic lesions or by the historyof the gradual onset of a focal neurological lesionpreceding the sudden change occasioned by thehemorrhage.
Septic embolism from the lesions of acute or sub-acute bacterial endocarditis may produce cerebral in-
farction with a considerable amount of hemorrhagicreaction in the infarct. A mycotic aneurysm, resultingfrom local inflammation and destruction of the wall ofan artery at the site of arrested septic material, mayrupture with severe bleeding resulting. At autopsy, noaneurysmal dilatation may be found, only the edge ofthe torn vessel. Mycotic aneurysms commonly are atthe bifurcation of small vessels, close to or in the sub-arachnoid space.
HYPERTENSIVE ENCEPHALOPATHY
The use of this term is specifically reserved for asyndrome in which there is a stereotyped sequence ofevents of serious import and dramatic development.This syndrome occurs in persons with moderate orsevere hypertension and is characterized by the in-crease in severity of the hypertension over a few hours'time, severe progressive headache often associatedwith nausea and/or vomiting proceeding to alterationsof consciousness (apathy progressing to coma), andconvulsions. There is generally severe hypertensiveretinopathy and there may or may not be evidence ofvarious degrees of the renal involvement so frequentlyassociated with hypertension. The CSF pressure is in-creased but the fluid is commonly otherwise normal.This is the classical basic syndrome of hypertensiveencephalopathy.
To these events and physical signs occasionallymay be added the history of the development of focalneurological signs and these signs are present on ex-amination. It is emphasized that the addition of thesefocal neurological signs (in order for the primarydiagnosis of hypertensive encephalopathy to beseriously considered) must be in the context of beingadded onto the syndrome described above. Otherwise,the clinician will be repeatedly making a diagnosis (inthe absence of the basic syndrome) of hypertensiveencephalopathy when the disorder is simply someother type of "stroke."
VASCULAR MALFORMATIONS AND DEVELOPMENTALABNORMALITIES: ANEURYSM
The principal effect of saccular or berry aneurysmsresults from rupture of the lesion with the productionof subarachnoid hemorrhage and brain damage.
Fusiform, diffuse and globular aneurysms consistof varieties of enlargement of the entire circumferenceof the artery. Fusiform aneurysms are tortuous,relatively circumscribed dilatations most commonlyinvolving the basilar artery or the internal carotidarteries within or near the cavernous sinus. The dis-tinction between fusiform aneurysms and diffuseaneurysms is probably of little importance. Globularaneurysms are a group in which there is markedspherical dilatation with the parent vessel coming inone side and leaving from the other side of the lesion.Any of these aneurysms may produce symptoms byexerting pressure on neighborhood structures or by be-ing the site of thrombosis.
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A localized degeneration of the cerebral cortex isfound in association with a port-wine stain (capillaryangioma) in the distribution of the first division of thetrigeminal nerve in the face. The cerebral cortex adja-cent to the angioma often contains calcium andproduces a double contour opacity on x-ray of thehead. These cerebral lesions may be associated withmental retardation, convulsive disorders and focalneurological deficits, although the lesions seldombleed.
CONGENITAL ABNORMALITIES IN THE ANATOMICAL PATTERN OFCEREBRAL ARTERIES
Many variations in the relative size of the vesselsmaking up the circle of Willis have been described.Deviations from the "normal pattern" are present inalmost half of the specimens which have been ex-amined. These deviations from "normal" areprobably only of clinical importance when vessels areeither absent or of threadlike size. Rarely, one or bothinternal carotid arteries are missing — occasionallyone is only rudimentary in size. Carotid-basilaranastomosis via the cavernous sinus rarely occurs.
INFLAMMATORY DISEASE OF ARTERIES
The arteritides form clinical manifestations byproducing varieties of metabolic encephalopathy orcerebral infarction.
INFECTIONS AND INFESTATIONS
Meningovascular syphilis is now a relativelyuncommon cause of stroke. Neurosyphilis produces achronic meningitis and the blood vessels of the brainand spinal cord, lying within the meninges, become in-volved. If the arteritic change involves the intima,thrombosis may result, producing cerebral infarction.These infarcts are characteristically small in size. Ifthere has not been previous antiluetic therapy, theCSF will invariably show an increased cell count andan elevation of the protein level. False-positive testsfor syphilis in the CSF are essentially nonexistent.
Pyogenic meningitis (influenza, staphylococcus,pneumococcus) and tuberculous meningitis oc-casionally cause cerebral arteritis and thrombosis.Generally, the primary diagnosis will already havebeen made; the initial clinical abnormality is rarely thesudden onset of a focal brain lesion.
Rare instances of arteritis may occur with typhus,schistosomiasis mansoni, mucormycosis, malaria andtrichinosis. Papillary and arterial changes andperivascular inflammatory cells may be present in thenervous system in typhus and other rickettsial dis-eases. The abnormal chemistry underlying the con-fusional psychoses, convulsions and coma which mayoccur with these lesions is not understood.Schistosomiasis mansoni infection may be associatedwith occlusion of small arteries and multiple cerebral
infarcts. In rare instances, diabetes mellitus may becomplicated by mucormycosis and occlusion of the in-ternal carotid artery.
A clinical state called "cerebral malaria" may oc-cur with malaria of the malignant or falciparumvariety. There is acute onset of hyperpyrexia, con-vulsions, somnolence deepening to coma, and oftendeath. If the patient lives, there may be focal brain in-volvement with hemiparesis, aphasia, etc. Thecerebral infarction is caused by the occlusion ofcerebral capillaries and arterioles by masses of redblood cells.
ARTERITIDES OF UNDETERMINED CAUSE
Cranial arteritis (temporal arteritis) uncommonlycauses the sudden onset of a focal brain lesion.However, the differential diagnosis of this disorder isextremely important since there is effective treatment(steroids) which will prevent the unilateral or bilateralblindness which occurs in more than one-third of thecases. In this disorder the branches, mainly of the ex-ternal carotid artery (especially the temporal arteries),are involved by subacute inflammation which maylead to thrombosis. There are generally some kind ofcranial or scalp discomfort, lassitude and malaise, andwithout treatment almost always marked elevation ofthe erythrocyte sedimentation rate. In some instances,the syndrome of amaurosis fugax has been caused bycranial arteritis.
Systemic lupus erythematosus produces arteriticchanges in the central nervous system (also at timesthe peripheral nervous system) which may cause aform of metabolic encephalopathy characterized bydelirium, confusional states and convulsions withdrowsiness, sometimes progressing to coma. In rareinstances, the effective inflammatory pathologyappears to be limited to one area so that a cerebral in-farct occurs. More commonly, micro infarcts andsometimes petechial hemorrhages are multiple andwidely scattered. In other instances where there issevere kidney involvement, intracerebral hemorrhageor hypertensive encephalopathy may occur. Veryrarely embolic occlusion of large and small brainarteries secondary to verrucous endocarditis (Libman-Sacks) happens.
Rheumatic arteritis is an uncertain specific entity.In acute rheumatic fever or in chronic endocarditis ofrheumatic origin, brain embolism may take place.Lupus erythematosus and rheumatic fever are closelyinterrelated, and it may be that lesions of the latter areactually those of the former.
Polyarteritis nodosa (panarteritis) directly in-volves the cerebral arteries in less than 10% of cases.The neurological picture produced is not commonlythat of the acute onset of cerebral infarction, althoughsuch may happen. There is more likely to be the oc-currence of a more general cerebral syndrome inwhich headache, confusional reactions and con-vulsions are present. The coexistence of mononeuritis
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multiplex may assist greatly in establishing a clinicaldiagnosis. Hypertension is commonly present and ifthere is renal involvement it may become so severe asto lead to hypertensive intracerebral hemorrhage orhypertensive encephalopathy.
Idiopathic granulomatous arteritis (Takayasu'sdisease) of the aorta and its major branches, includingthe common and internal carotid arteries, occurs fromtime to time in all countries, although it was originallydescribed in Japan. It is frequently referred to as the"pulseless disease" due to the occlusion of carotid andlimb arteries produced. Along with various types ofemboli and angioma, this disorder should be con-sidered in the differential diagnosis of unexplainedstroke in young adults.
Moyamoya (a Japanese expression for somethinghazy like a wisp of fog drifting in the air) disease is arare one, which in its fully developed form ischaracterized by an angiographical picture showingocclusion or stenosis at the carotid bifurcation with anetlike cluster of vessels intracranially on the sameside. In children, the disorder is commonly charac-terized by attacks of paroxysmal hemiplegia, while inthe adult the onset may be sudden with seizures andsubarachnoid hemorrhage.
Thromboangiitis obliterans (Winiwarter andBuerger) is not included; its existence as an entity isuncertain.
DURAL SINUS AND CEREBRAL VENOUS THROMBOSES
In everyday practice, intracranial phlebothrombosisand thrombophlebitis are uncommon and do not oftencause confusion in the differential diagnosis of stroke.With inflammation in these structures, blood may bedammed back into small venules and capillaries,obstructing venous drainage so that local brainischemia occurs sometimes followed by cerebraledema and hemorrhagic infarction. Focal convulsiveevents may occur.
Vein and sinus thromboses were much more com-mon in the pre-antibiotic era and were secondary topyogenic infections of the mastoid, paranasal sinusesor face. The inflammatory process sometimes travelsto the larger veins directly or may come about fromthe production of a local osteomyelitis, or by produc-ing thrombophlebitis of small diploic vessels whichcarry the infection intracranially.
Thrombosis of cerebral veins may be seen shortlyfollowing childbirth or a surgical operation. Theformer may be due to hypercoagulability of the blood(hyperfibrinogenemia or increased blood plateletcount).
The manifestations greatly depend upon the siteand severity of the cerebral pathological process. Con-vulsions and/or hemiparesis may occur; the CSF maybe bloody. Weakness involving only a leg or an arm(sparing the face) is likely due to a lesion adjacent tothe sagittal sinus, the common site of infarction, ifocclusion of the sagittal sinus has taken place. If the
sagittal sinus is occluded, another clinical picture isthat of bilateral neurological signs. With this and/orocclusion of the transverse sinuses, there may be an in-crease in intracranial pressure which can be associatedwith headache, choked disks and visual obscurations.The changes in the CSF are variable, from a mild in-crease in the white blood cell count and rise in thepressure of modest degree to bloody CSF under highpressure if extensive hemorrhagic infarction has takenplace. In those instances where the venous thrombosisis secondary to a purulent meningitis, the charac-teristic CSF findings of the latter will be present.
THE CLINICAL NEUROLOGICAL PICTURE
The clinical neurological picture is determined by thesite of the brain damage (infarction or hemorrhage). Itis now common practice to divide the brain bloodsupply into two major categories: (1) the carotidsystem, and (2) the vertebrobasilar system.
Internal Carotid Artery
Occlusion of the internal carotid artery in the neckdoes not produce any characteristic clinical picture. Inthe presence of adequate intracranial collateral cir-culation, internal carotid artery occlusion mayproduce no symptoms or signs. At the other end of thespectrum, in instances where the collateral circulationis faulty, there may be infarction of a major portion ofthe ipsilateral hemisphere with contralateral hemi-plegia, hemianesthesia, homonymous hemianopia andaphasia (if the dominant hemisphere is involved).Stupor may come quickly, particularly if there is brainswelling with compression of the brain stem. Withocclusion of the internal carotid artery in the neck,there is very seldom a simultaneous onset of perma-nent blindness in the ipsilateral eye together with thecontralateral hemiplegia, hemianesthesia, andaphasia. Likewise, occlusion of the internal carotidartery in the neck is seldom a direct cause of perma-nent ipsilateral blindness (without hemispheric signs).Much more common than the very severe syndromeoutlined above is the circumstance where there isatherosclerotic occlusive disease in the internal carotidartery in the neck and an associated distal arterialocclusive event which produces only a fragment of theneurological defect which would occur if all theterritory supplied by the carotid artery were infarcted.Thus, the neurological picture may range from amonoparesis to hemiparesis with or without ahomonymous defect in vision, a variety of im-pairments of speech and language, different types ofagnosia and a complete range of partial to full sensoryabnormalities. A cervical internal carotid lesion isparticularly to be suspected as a pathogenetic sourceof a sudden-onset hemispheric neurological defectwhen there have been antecedent characteristic TIAs(particularly amaurosis fugax) or a long systolic orsystolic-diastolic bruit at the take-off of the ipsilateralinternal carotid artery, ipsilateral decrease in retinal
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artery pressure or cholesterol or fibrin-platelet emboliin the appropriate eye.
Middle Cerebral Artery
The most significant clinical subdivision of theinternal carotid artery system is the middle cerebralartery (MCA) or what might be more appropriatelycalled the middle cerebral arterial system. Occlusionof the first portion of the MCA is almost alwaysassociated with the production of a neurologicaldefect. Such a lesion is more distal in the total carotidarterial system and occurs at a site where a chance forcollateral supply via the circle of Willis is no longerpresent. Occlusion of the artery is said tocharacteristically produce a contralateral hemiplegia,hemihypesthesia or hemianesthesia, homonymoushemianopia and aphasia if the defect is in the domi-nant hemisphere. However, occlusive disease in themiddle cerebral arterial system more commonlyproduces a portion or fragment of this total picture,the variations in the neurological findings providing abroad spectrum of abnormalities. If the infarct is verylarge, there is more likely to be brain edema withbrain stem compression and stupor a few hours afterthe onset. Depending on the pattern of collateral bloodsupply and the actual artery or arteries occluded in themiddle cerebral system, there will be such variationsas: from hemiplegia to a mild paresis of one side of theface alone, mild weakness of one upper extremityalone, etc. If the focal impairment of blood supply isin the posterior portion of the middle cerebral system,there is more likely to be homonymous hemianopia ora partial homonymous visual field defect, aphasia ordysphasia. If penetrating branches of the MCA arethe only vessels occluded, the defect may be onlymotor, or if arteries to sensory cortex are the onlyones involved a cortical-type hypesthesia will result. Itis emphasized that there is a wide spectrum ofneurological abnormalities (including many variationson the parietal lobe syndrome) which may occur withocclusive disease in the middle cerebral arterialsystem.
Anterior Cerebral Artery
Occlusive events in the main stem of the anteriorcerebral artery or its various branches also areassociated with the production of a variety of clinicalevents. No solitary syndrome has been delineated ascharacteristic of occlusion; this is because of thevariety of patterns of branches of the vessels and par-ticularly the variety of patterns of collateral supplyavailable. When there is paralysis or severe weaknessof the opposite lower extremity with mild or no in-volvement of the opposite arm, a lesion in the distribu-tion of the anterior cerebral artery is likely. Mentalchange, often subtle and mild but sometimes severeenough to be called dementia, dyspraxia or apraxia ofthe use of an extremity or in walking, grasping andsucking reflexes, and problems with maintenance of
continence of bowel and bladder may be associatedwith infarction of the brain in this distribution.
Vertebrobasilar Arterial SystemThe vertebrobasilar system supplies blood to themedulla, pons, cerebellum, mesencephalon, thalamus,occipital lobes, and even portions of the temporal-occipital and parieto-occipital junctions. The mostcommon defects include abnormalities of motorfunction: weakness, clumsiness, or paralysis of anycombination of extremities up to quadriplegia withappropriate pyramidal tract signs combined with uni-lateral or sometimes bilateral cranial nerve palsies,particularly oculomotor defects or signs of trigeminalnerve or facial nerve involvement. A so-called"crossed" defect (motor or sensory on one side of theface and the opposite side of the body) is evidence of abrain stem lesion until proved otherwise. Involvementof sensory function is common and this may be in anycombination of extremities including all four or maybe in both sides of the face or mouth. If the occipitallobes are the site of ischemia, there will be loss of vi-sion, complete or partial in both homonymous fields(bilateral homonymous hemianopia). Ataxia, im-balance, unsteadiness or dysequilibrium notnecessarily associated with vertigo may occur becauseof labyrinthine system or cerebellar system defects.Vertigo, particularly in such instances as the lateralmedullary syndrome, is a very common complaint andwhen produced by brain stem infarction is usuallyassociated with one of several types of nystagmus.Dysphagia and/or dysarthria may occur in combina-tion with any of the abnormal neurological signsalready mentioned. The most important evidence for abrain stem locus of the ischemia is the bilaterality ofsensory or motor abnormalities coupled with definiteevidence of cranial nerve (III to IX) involvement. Im-pairment of consciousness early in the course of eventsis unusual. If nystagmus alone is noted, it may be im-possible to decide whether the lesion is in thevestibular-cerebellar system in the brain stem or in aperipheral portion of the vestibular system. However,if the nystagmus has added to it impaired ocular rota-tion or some evidence of an upper motor neuron defectin one or more extremities or some abnormality suchas dysarthria or dysphagia, the anatomical site of theischemia is identified as brain stem. The neurologicalsyndrome in vertebrobasilar system acute occlusivedisease develops during hours or a few days withprogression frequently in stuttering or stepwisefashion. These repeated steps of progression may oc-cur over a period of 72 to 96 hours and there is,therefore, the possibility of presuming that theprogression has been "completed" only to find thatthis is not true.
Posterior Cerebral Artery
As has already been mentioned for other maincerebral arteries, the posterior cerebral artery supply
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actually constitutes a subdivision of the vertebro-basilar system. The neurological abnormality pro-duced by occlusive disease in this system depends onthe site of the occlusion or stenosis and on the effec-tiveness of the available collateral flow. If the occlu-sion is distal, a homonymous hemianopia or evenquadrantanopia may result. There may be variationsin the position of the "watershed" between theposterior portion of the middle cerebral system supplyand the anterior portion of the posterior cerebralsupply so that a lesion in the posterior cerebral arteryon the dominant side may produce dyslexia,dyscalculia, and a variety of speech and language ab-normalities, while on the nondominant side portionsof a parietal lobe syndrome defect may occur. If theocclusion is more proximal in the posterior cerebralarterial system, there may be a contralateralhemiparesis (cerebral peduncle), third nerve palsy(oculomotor), or a contralateral thalamic syndrome(posterior thalamus). Cortical blindness and varietiesof visual-verbal agnosia may be produced if both oc-cipital lobes are affected because of impaired bloodflow to the territories of both posterior cerebralarteries. The patient may be unaware that vision isaffected or may have strange variations in behavior.
Vertebral Artery
Although it is now common practice to use the phrasevertebrobasilar system, it has been demonstrated thatocclusion of a vertebral artery at or near the origin ofthe posterior inferior cerebellar artery will produce alateral medullary syndrome (Wallenberg's syndrome)which is characterized by the sudden onset of severerotational vertigo, nausea and vomiting, dysphagia,ipsilateral cerebellar ataxia, ipsilateral Homer's syn-drome and involvement of pain and temperature senseon the ipsilateral face with contralateral loss or im-pairment of sensation for pain and temperature on theextremities and trunk. When there is severe stenosis orocclusion of a subclavian artery, there may be reversalof flow in the ipsilateral vertebral artery. This has notbeen consistently associated with any neurologicalsymptoms or signs. When one vertebral artery is verysmall and the other unusually large, occlusion of theprincipal vertebral artery may be associated withsymptoms and signs usually occurring with main stembasilar artery occlusive events.
C. General cerebral dysfunctionThis category refers to general cerebral ischemia,
which results from reduction in blood supply to thebrain, yet is applicable also to lesions of other causes.This category does not imply the presence or absenceof disease of the cerebral arteries.*
*In the present state of our knowledge, chronic dementia of theelderly without evidence (clinical or pathological) of neurologicaldeficits of vascular origin is rarely caused by cerebral athero-sclerosis alone. Although these patients are frequently diagnosed ashaving "arteriosclerotic dementia," "cerebral atherosclerosis withdementia," or "chronic brain syndrome with cerebral
1. TransientThese are brief episodes of general cerebral
ischemia, the classic example of which is simple faint-ing. It is possible that loss of consciousness may resultfrom ischemia of focal areas of the brain, areas whoseintegrity is required for maintenance of consciousness;in those instances in which a decision can be made thatsuch episodes are in fact focal, the patient should becategorized under I.B.
2. ProlongedThe acute onset of generalized brain ischemia is
most commonly a result of cardiac arrest or somecause of great decrease in cardiac output.Consciousness may be lost or impaired for theremainder of the patient's life. If the decreased bloodsupply is of very short duration, there may be perma-nent damage to higher intellectual function. Agradually progressive onset is uncommon in cerebro-vascular disease per se; it is more likely to beassociated with some change in the blood, i.e., per-nicious anemia, azotemia, hepatic disease, etc.
Part V. Clinical Phenomena (History,Physical Examination, Laboratory Ex-amination, Roentgen Examination,Other)
A. HistoryThe family history may contain significant infor-
mation about hypertension, diabetes and cardiac dis-ease. The past history of the patient may contain rele-vant material about these same items as well as otheritems, including previous stroke.
In reviewing the history of the present illness, thephysician must probe for answers (direct or by in-ference) relevant to different sections of thisClassification of Cerebrovascular Diseases. If thecomplaints have been transient, the circumstances ofonset, including activity being performed, physicalposition of the patient, quickness of development ofthe symptoms, and duration as well as the listing ofthe complaints must be described. In the history theremay be important information concerning thepathophysiological mechanism, i.e., cardiac source foremboli or intracarotid source for emboli if there hasbeen amaurosis fugax. The story of rapid onset andprogression of a focal neurological deficit withheadache against a background of untreated hyperten-sion may point the way to a diagnosis of intracerebralhemorrhage. Antecedent TIAs statistically stronglyfavor a diagnosis of cerebral infarction rather thancerebral hemorrhage. These are but a few examples ofthe fashion in which history-taking should be designed
atherosclerosis," their conditions are often confused with other tox-ic metabolic or degenerative diseases (e.g., Alzheimer's disease orsenile dementia).
A patient with focal neurological deficit of vascular origin, e.g.,hemiparesis plus a defect in mentation, should be classified underI.B.
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to bring out information concerning "Clinical Stage,Pathophysiological Mechanisms, Anatomy, andPathology."
B. Physical examination1. GeneralIn the general physical examination the emphasis
is directed toward detecting evidence of any pathologyin the cardiovascular system — evidence which maybe of great importance, such as severe arterialhypotension with a cardiac arrhythmia, or evidencewhich may be of minimal importance, such as a bloodpressure level of 150/90 mm Hg. Attention should begiven to heart rate, rhythm and size, blood pressure inboth upper extremities, heart sounds, peripheralpulses and detection of congestive failure includingdyspnea, venous engorgement, hepatomegaly, ascites,pedal edema and pulmonary congestion or edema.
Skin lesions such as ecchymosis and petechiamay suggest processes which produce similar lesionsin the brain. Skin tumors as well as masses in othersites may be the origin of intracranial metastases.
2. NeurologicalThe neurological examination and the interpreta-
tion of the neurological findings often make feasiblethe diagnosis of the site of the nervous system lesion orlesions. Certain combinations of neurological signsalmost establish a diagnosis, i.e., lateral medullarysyndrome, bilateral homonymous hemianopia, etc.Often the accurate inspection of a patient with "con-fusion" will detect aphasia and the physician thenknows that the neuropathology is focal rather thandiffuse. The reader is referred to one or several of themany textbooks which describe the neurological ex-amination.
3. Vascular (largely neurovascular) examinationIn order to place special emphasis on the impor-
tance of certain abnormal physical signs, certain por-tions of the examination have been grouped togetherunder this term. These include: (a) inspection ofvessels, (b) palpation (including carotid sinus massageand carotid compression), (c) auscultation at cervicaland cranial sites, (d) ophthalmoscopy (including in-spection of the retina for emboli, cotton-wool patches,vascular occlusions, hemorrhage and ischemicretinopathy), and (e) ophthalmodynamometry.
a. Inspection of vesselsCranial arteritis is an unusual cause of stroke.
However, accurate diagnosis is vital to correct treat-ment and significant arterial change may be detectedby thoughtful viewing of superficial temporal arteries,coupled with palpation.
b. PalpationPalpation of cervical-cerebral vessels should be
done gently. Minor differences in pulse between sidesare difficult to interpret and it may be impossible todistinguish a pulse coming from the first portion of theinternal carotid artery or from the external carotidartery. Patients suspected of having atherosclerosis ofcervical vessels may have ulcerated plaques or early
thrombus forming; both are situations wheremanipulation of the arteries could dislodge emboli.Similarly carotid compression tests and carotidmassage have inherent danger in patients withcervical-cerebrovascular disease. These importantdangers include dislodging emboli, temporarilydecreasing carotid flow and production of a significantchange in cardiac rhythm. If the "sick sinus" syn-drome is suspected, massage should be performedonly with continuous ECG, EEG and blood pressuremonitoring as well as with personnel and equipmentavailable for the care of a cardiac emergency.
c. AuscultationAuscultation of the cervical vessels often provides
important evidence concerning the pattern of bloodflow. A bell-type stethoscope is most easily applied inthe supraclavicular fossa and over the eyes withoutusing physical pressure which may produce artifac-tual noise. The bell of the stethoscope is first placedover the aortic valve and then moved (1 cm or less at atime) superiorly. This progressive movement of thestethoscope is necessary to distinguish transmittedcardiac sounds from sounds arising in the innominate,subclavian, common carotid or internal carotidarteries. A neutral position (patient sitting or lyingwith face straightforward) is less likely to createsounds difficult to interpret than a variety of twistedneck positions. If respiratory (tracheal) soundsobscure auscultation, the patient is requested to"stop" breathing for a few seconds; then "start"breathing is the instruction. Bruits should be gradedfor loudness, the scale being 1 (least) to 6 (loudest);i.e., 1/6 is barely audible, 6/6 is the loudest. The tim-ing (systolic, diastolic, systolic-diastolic), duration(short, medium, long) and quality (rough, soft,smooth, etc.) should be described. A bruit of 1/6loudness is of little significance, while one of 2/6 to3/6 loudness, long systolic-diastolic duration, andtiming of fairly high pitch over the origin of the inter-nal carotid artery means high-grade carotid stenosisuntil proved otherwise. A soft (1/6 to 2/6) diastolicsound, varying with slight change in neck position, iscommonly an unimportant venous hum. Soft,sometimes almost continuous cervical bruits are fairlycommon in children and ordinarily do not indicate thepresence of significant pathology. By carefully re-cording the description of bruits and correlating thiswith arteriographical and other findings, the examinerwill quickly learn to correctly interpret such sounds.
If the patient's history suggests the presence of aneoplasm or arteriovenous malformation, ausculta-tion over the cranial vault and orbits should be done.When there is a complaint of a rhythmic head noise,particular attention is directed to auscultation of thelocus of the sound. It may be necessary to wet the hairof the patient to eliminate artifactual noise. Ausculta-tion of the orbit is performed by instructing the patientto close the eyes, placing the bell of the stethoscopeover the eye and having the patient open the eyes to
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eliminate artifactual muscle sounds. Soft bruits overthe cranial vault of children are of little importance.Loud bruits may be caused by angiomas,arteriovenous shunt and, rarely, brain neoplasms. Acontinuous, almost machinery-like murmur or bruitover the orbit is most commonly caused by a carotidcavernous arteriovenous shunt. Noises heard over theorbit have been of little help in establishing the siteand severity of lesions of the internal carotid artery.
d. OphthalmoscopyOphthalmoscopy provides an opportunity to
directly inspect small blood vessels, blood vesselswhich are a direct continuation of the internal carotidarterial system. In office and hospital practicerelatively little use is made of this simple, safe methodof acquiring important data concerning the cervical-cerebral portion of the circulation. The retina shouldbe inspected for arterial or venous occlusion, emboli(cholesterol, platelet-fibrin, calcific, mixed, foreignbody), hemorrhages, cotton-wool patches, venousstasis, microaneurysms, changes associated witharterial hypertension, papilledema and ischemicretinopathy.
1) Retinal emboliIn the last two decades the importance of detect-
ing (with the ophthalmoscope) a retinal embolus oremboli has been demonstrated. The most commonemboli are made up of cholesterol crystals. Theseappear as shiny orange-yellow plaques often situatedat the bifurcation of retinal arterioles. The plaque mayappear to be wider than the arteriole; one sees the out-er dimension of the column of red blood cells ratherthan the wall of the arteriole. Pressure on the eye oftenchanges the position of the embolus slightly — thematerial may appear to glint or change shade, acharacteristic sometimes referred to as a heliographicreflection. The blood flow in the arteriole is oftenseemingly unimpeded by these bright orange-yellowplaques. These emboli may move distally and oftendisappear in a few days. The presence of one or morecholesterol retinal emboli indicates that there is or hasbeen an ulcerated atheromatous carotid (internal) le-sion until proved otherwise.
Another important type of embolus in retinalvessels consists of gray-white material, thought toconsist of blood platelets and fibrin. These emboli maybe long and seen to move through an arteriole but arecommonly stationary; pressing on the eye does notmove the embolus, and there is no heliographic reflec-tion. Blood does not appear to flow past these emboli;there may be infarction of the retina. Special studiesshow that some of these emboli have a high lipid con-tent. In many instances the source of these emboli isan atheromatous lesion at the origin of the internalcarotid artery. Particles of calcium are another type ofretinal embolus. These are white, generally short, andstationary. Calcium emboli commonly come fromheart valve lesions.
Septic emboli, talc and cornstarch emboli as well
as others may be seen in the retina but are less com-mon than those already described.
e. OphthalmodynamometryOphthalmodynamometry is a procedure for
measuring the arterial systolic and diastolic pressuresin the main retinal branch or branches of theophthalmic artery. The convex foot-plate of the in-strument is applied to the conjunctiva over the inser-tion of the lateral rectus muscles in a horizontalmanner so that the instrument points directly towardthe opposite eye. When measurements are being madein the patient's right eye, the instrument is held in theobserver's left hand and the ophthalmoscope is held inthe right hand. To measure pressure in the left retinalartery, the observer holds the ophthalmodyna-mometer in the right hand and the ophthalmoscope inthe left. When the instrument is in position, theobserver must bring the central artery on the disk intofocus through the ophthalmoscope. The instrumentthen is pressed gradually against the eye to raise theintraocular pressure sufficiently to exceed the diastoliclevel of the blood pressure in the retinal artery. Thediastolic pressure is that level which produces the firstcollapsing pulsation of the artery. At this point afinger is applied to the brake on the instrumentand the reading is taken from the scale. The oph-thalmodynamometer is reapplied and several morereadings are taken to insure accuracy. The sys-tolic pressure is obtained by increasing the force ofapplication of the instrument still further. The visiblearterial pulsation gradually diminishes as the pressureincreases, and when pulsation ceases, the reading onthe instrument is the systolic blood pressure.
Ophthalmodynamometry is ordinarily useless un-less the arterial pressures are measured in both eyes. Itcannot be performed unless the patient is cooperative.It is helpful to instill a mydriatic; this should not bedone if there is glaucoma. The test should not be donesoon after cataract extraction, recent retinal detach-ment, etc.
The clinical significance of the retinal arterialpressures is dependent on comparing the values in thetwo eyes. A difference of 15% to 20% almost always isa sign of stenosis or occlusion of the internal carotidartery ipsilateral to the lower pressure. The arterialpressure may be equal and/or normal in the presenceof unilateral carotid stenosis or occlusion because ofthe development of collateral blood supply.Immediately following acute occlusion of an internalcarotid artery the ipsilateral retinal arterial pressuredrops. Return of the pressure to that of the con-tralateral eye depends on the speed with whichcollateral circulation develops. A marked decrease inthe retinal arterial pressure (brachial arterial pressureremaining normal) when the patient moves from thesupine position to the upright position (ocularorthostatism) is important evidence of carotidocclusive disease.
A suction ophthalmodynamometer requiring a
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source of electric power is available. It is safe andhighly accurate, but unhandy.
f. Neurological signs produced by positionIf the patient describes phenomena which are
precipitated by certain positions of the head and/ortorso, it is wise to carefully try to reproduce the symp-toms and simultaneously search for physical signs ofdysfunction. Thus, extension of the neck may beassociated, in the patient's history, with the onset of"dizziness;" have the patient reproduce the motionand observe for nystagmus. The history provides aclue to the existence of orthostatic hypotension. Theseare examples of a variety of such phenomena.
C. Laboratory examinationThere are a number of laboratory tests which are
of aid in the diagnosis and management ofcerebrovascular disease, but none of them can ap-proach in general usefulness a careful history andphysical examination.
1. Urinalysisa. SugarUnder usual circumstances, there is no glucose in
the urine. This is a crude but very useful screening testfor abnormal glucose metabolism.
b. ProteinNormally, on qualitative evaluation, there is no
protein in the urine. This is a crude but valuable screenfor either abnormal substances coming through thekidney or for abnormal kidney function.
c. Sediment microscopyThis examination may give valuable information
about such things as the presence of vasculitis and in-flammatory disease of the kidney as well as being acrude screen of renal function in patients withhypertensive vascular disease.
d. OtherA wide variety of tests for substances including
those for vanilmandelic acid, porphobilinogen,cyanide-nitroprusside test for homocystinuria,aldosterone, lead, metanephrines, etc., may be done inselected instances but are only rarely of help in themanagement of a stroke patient.
2. Blooda. Test for syphilis, such as VDRL, etc.In the 1970s, meningovascular lues, or luetic
vasculitis, is not a common cause of stroke; however, ablood screening test for syphilis should still be in-cluded in the laboratory profile.
b. Red blood count, white blood count, bloodhemoglobin, hematocrit, and differential blood count
These tests frequently give valuable informationconcerning the presence of hemoconcentration sec-ondary to dehydration, the presence of polycythemiavera which in turn may be associated with thrombosisor with hemorrhage, and other forms of polycythemia.The differential blood count may suggest the existenceof or the beginning of an inflammatory process andthe peripheral blood film provides the opportunity toestimate the number and types of platelets.
c. Erythrocyte sedimentation rate (ESR)While it is relatively uncommon for a form of
vasculitis (temporal arteritis, giant cell arteritis, lupuserythematosus, polyarteritis nodosa, etc.) to bedirectly a cause of stroke, such an etiology may be oftremendous importance and the diagnosis may be im-mediately suggested by the marked elevation of theESR which is so commonly present in acute vascular(collagen) disorders such as those referred to.
d. Fasting blood sugar or casual blood sugarThis is an excellent screening test for the detec-
tion of diabetes mellitus and, in certain patients whoare acutely ill, hypoglycemia of a variety of originsmay be significant.
e. Creatinine or ureaEither is a reasonably good screening test for
renal disease, especially when coupled with urinalysis.If either creatinine or urea is normal in the blood andurinalysis is normal, significant renal disease generallyis not present.
f. Cholesterol — triglyceridesSlight or moderate elevations of cholesterol
and/or triglycerides are probably of little significanceat the time a stroke actually occurs. However,elevated blood cholesterol has been identified as alikely risk factor for occlusive cerebrovascular diseasein persons under 50 years of age. Elevation oftriglycerides has been indicated as a risk factor in thedevelopment of coronary heart disease. Thus, one orboth substances may be important to the prevention offurther focal cerebral ischemia in a person with TIAsor in a patient who has had a completed cerebral in-farct. When there is marked elevation of the values, asin familial hyperlipidemia, the risk of cerebral infarc-tion is definitely increased.
g. Prothrombin timeIn certain selected instances anticoagulant
therapy may be initiated early in the course ofocclusive cerebrovascular disease; in such instances itis important to have the results of this test for"baseline" purposes.
h. Uric acidThere is little direct importance of mild to
moderate hyperuricemia with the practical manage-ment of an acute progressing stroke or even a com-pleted stroke. However, hyperuricemia has beenassociated with atherosclerosis of the coronary,peripheral and cerebral arteries and, therefore, may besomewhat distantly related to the profile of "risk fac-tors for stroke" and may be obtained in the work-upfor this reason.
i. OtherHere included are numerous tests which may be
important in the care of selected patients but are notconsidered in the usual list for essentially all patientsthought to have some form of cerebrovascular disease.These include: acid-base balance, bilirubin, brom-sulphalein dye retention, calcium, catecholamine,chloride, clot retraction, whole blood coagulation
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time, plasma coagulation time, partial thromboplastintime, plasma fibrinogen, euglobulin lysis time, serumosmolality, arterial oxygen saturation, oxygen tension(air), potassium, protein electrophoresis, sodium, freeand/or total thyroxine, enzymes, partial pressure ofcarbon dioxide and pH. It may be that tests of plateletadhesiveness and ability to aggregate may becomeclinically important.
3. Cerebrospinal fluidThis examination should be performed when the
clinician has a serious problem in establishing thedifferential diagnosis of the intracranial pathology —bleeding, focal ischemia or inflammatory disease. Thefluid is ordinarily obtained by lumbar puncture andthe examination should not be considered "routine" inthe work-up of the patient. The amount of fluidwithdrawn depends upon the question to be asked; acubic milliliter will be adequate to demonstrate grossbleeding, while the amount needed will be muchgreater if the search is for the etiology of a meningitiswhich is increasing the number of lymphocytes in thefluid. In some instances the clinician may be reluctantto do a lumbar puncture even though there is nopapilledema because of clinical evidence of increasedintracranial pressure with the apparent brainpathology limited to one hemisphere. If there is amacroscopic amount of blood in the CSF, it is notpossible (without analysis of the history and aneurological examination) to know whether thebleeding comes from a primary subarachnoid site orfrom an intracerebral source. The observations madedepend on the clinical situation.
a. PressureInformation about the CSF pressure is of only
relative value in the differential diagnosis. TheQueckenstedt maneuver (compression of the jugularveins) should not be performed for the differentialdiagnosis of intracranial lesions. In certain instancesthe examiner will not wish to withdraw enough fluid toeven measure the pressure in the usual manometer.
b. ColorNormally the CSF is crystal clear and colorless.
If there is gross blood and the intensity of colordecreases after a few drops of fluid appear, thebleeding is due to trauma to a blood vessel. If the fluidis xanthochromic immediately after it is withdrawn orwithin a very few minutes, the xanthochromia hasbeen produced by something other than a traumaticlumbar puncture. A trace of xanthochromia may bequickly detected by putting a cubic centimeter or lessof CSF in a Wassermann tube and comparing theappearance with a tube containing water. The line ofvision should be directed down the length of the tubeand the background should be white. The color maybe produced by high CSF protein content or icterusbut is commonly due to intracranial bleeding (rarelyintraspinal bleeding). If the CSF has a "ground-glass"appearance, there are generally more than 400 whiteblood cells present per cubic milliliter of fluid.
c. CellsThe CSF should be examined for red blood cells
and white blood cells. In certain instances yeast,neoplastic cells and bacteria may be detected. Itshould be noted that in the usual setting in which CSFexamination is performed in a patient stronglysuspected of having cerebrovascular disease theappearance of the fluid and the microscopic examina-tion of the fluid give the answer to the question mostcommonly asked: "Has there been bleeding into thesubarachnoid space?"
d. ProteinModest elevation of the CSF protein is common
in patients with various categories of cerebrovasculardisease and is not of particular assistance in es-tablishing an accurate differential diagnosis. In thisgeneral diagnostic situation the electrophoretic frac-tionation of the proteins is only rarely of assistance indifferential diagnosis.
e. GlucoseUnless there is massive subarachnoid hemor-
rhage, CSF glucose level is not commonly altered byvarious categories of cerebrovascular disease. Whenattention is to be paid to the glucose determination,the blood and CSF glucose levels should be drawnsimultaneously to determine whether the normal ratio(CSF glucose approximately two-thirds the bloodglucose) is present.
f. Test for syphilisA positive test for syphilis in the CSF is highly
significant; either such a result is a laboratory error orthe chances are very great that the patient has lueticinvolvement of the nervous system, active or inactive.Although meningovascular syphilis is less commonnow as a cause of stroke than a few decades ago, thisetiology continues to occur.
g. EnzymesGlutamic oxalacetic transaminase (GOT), lactic
dehydrogenase (LDH), and creatine phosphokinase(CPK) in the CSF have been studied but are notsignificantly helpful in the diagnosis of variouscategories of cerebrovascular disease or in the distinc-tion between cerebrovascular disease and brainneoplasms. Therefore, these tests ordinarily are notperformed.
h. Gases and pHCSF pH and Pa, are not ordinarily done as a
portion of the differential diagnostic studies or for theclinical management of the patient. The tests havebeen done for investigative purposes.
4. ElectrocardiogramBecause of the full documentation of the active
interrelationship between various forms of cardiacpathology, including disturbances of rhythm, andcerebral ischemia (both diffuse and focal), an elec-trocardiogram should be obtained in essentially allpatients suspected of any category of cerebrovasculardisease. If there is no history of any cardiovascularsymptoms or pathology, if heart size, sounds and
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rhythm are normal to clinical examination, and if theblood pressure is normal, active cardiac pathology isunlikely. However, in rare instances, a "silent"myocardial infarct may be present and there may besome change in the cardiac conducting mechanismswhich the clinician cannot detect by physical examina-tion. If the electrocardiogram is normal, it is unlikelythat there is any intermittent disturbance of rhythmwhich might play a role in the pathogenesis of eitherdiffuse or focal cerebral ischemic events. A possibleexception to this may be rare instances of "sick sinussyndrome." If there is a history suggesting some tran-sitory change in cardiac rhythm, an abnormal cardiacphysical finding or a certain change in the electrocar-diogram (an example being left ventricular hyper-trophy with a right bundle branch block), it is oftenimportant to obtain long-duration electrocardio-graphical recordings by the use of equipment such asthe Holter monitor.
5. ElectroencephalogramIn the usual stroke patient (typical TIAs, most in-
stances of progressing stroke and almost all cases ofcompleted stroke) the electroencephalogram adds lit-tle significant information and is not necessary as aportion of the work-up of the patient. Commonly, invertebrobasilar disease the electroencephalogramshows no focal abnormality. It has been said thatserial electroencephalograms may very well portrayaccurately the favorable or unfavorable progression ofthe brain lesion in stroke. However, the clinician canalmost always get this same information by spendingthree or four minutes with the patient one or moretimes a day.
In selected instances an electroencephalogrammay reveal multiple focal abnormalities, thus givingpotential evidence concerning the presence of multiplemetastatic lesions.
During carotid arterial surgery and cardiac sur-gery, the electroencephalogram is of value in monitor-ing brain function. This is only true if the personnelare knowledgeable about the effect of anesthesia onthe electroencephalogram. In rare instances where theclinician is unable to establish a differential diagnosisby the procedures described in the preceding pages,the combination of electroencephalography andechoencephalography may be helpful in the first fewhours following the onset of the focal neurological ab-normality. If, within 36 hours of the onset, the elec-troencephalogram shows a focal abnormality and theechoencephalogram reveals a shift of 2 mm or more ofthe midline away from the side of the EEG focus, thestatistical chances are that the lesion is an in-tracerebral hemorrhage or other expanding mass.
In certain instances, the electroencephalo-graphical recordings may be of aid in evaluating thestage of "irreversible coma." The various criteria for"brain death" have been outlined by the ad hoc Com-mittee of the American ElectroencephalographicSociety on "Criteria for the Determination of
Cerebral Death."In medical centers where computerized axial
tomography (e.g., EMI scanner, ACTA scanner, etc.)is available, there is very little need for EEG in thediagnosis of stroke patients.
6. EchoencephalographyPhysicians or trained technicians can perform
echoencephalography equally well. A shift of midlinestructures can be determined with an accuracy of 1 to2 mm; a shift of 3 mm or more is ordinarily consideredabnormal. Although the test is safe, it is seldom ofsignificant help in establishing a differential diagnosis,particularly if the clinician has been willing to obtain acareful history and do the examinations recommendedin the preceding pages. A shift of the midline struc-tures may be produced by cerebral infarction withedema, intracerebral hemorrhage, subduralhematoma, brain abscess, brain neoplasms, and brainatrophy. As mentioned in the paragraphs about elec-troencephalography, a shift of midline structures ofmore than 2 mm within 36 hours of the onset ofpresumed cerebrovascular symptoms and signssuggests that the lesion is an intracerebral hemorrhageor other expanding mass. However, a shift developingafter 36 hours from the time of onset may be due toedema associated with infarction.
In medical centers where computerized axialtomography (e.g., EMI scanner, ACTA scanner, etc.)is available, there is very little need forechoencephalography other than its use in the evalua-tion of a patient in the emergency room.
Composite B-mode ultrasonography using radartechniques is being developed. The cervical portion ofthe carotid arteries has been scanned by several in-vestigators but the method is still not feasible forclinical use.
Doppler techniques, including the use of aDoppler fiowmeter, are under research and may bedeveloped for clinical use.
7. Isotope brain scanThe static brain scan has become an established
procedure for the detection of intracranial neoplasms.However, in medical centers where computerized axialtomography (e.g., EMI scanner, ACTA scanner, etc.)is available, there is now very little need for the staticbrain scan in the differential diagnosis of focal brainlesions. Non-neoplastic lesions, such as subduralhematomas, abscesses, cerebral infarcts or in-tracerebral hemorrhages, may at times produce focalabnormalities in the static brain scan. Brain scanningequipment is now widely available; however, it is un-fortunate that in many instances clinical personnelcompetent to use and evaluate the scans forneurological differential diagnosis are not available.The duration of time elapsing between the injection ofthe radionucleotide and the scanning is of paramountimportance. Arteriovenous malformations are mostcommonly detected if the examination is done within30 minutes of the injection, while cerebral infarcts are
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more likely to be detected if the scanning is delayedtwo to four hours after the injection of the radioactivematerial. Commonly, cerebral infarcts are not iden-tifiable by brain scanning until the third to eighth dayfollowing the occurrence of the lesion, and if a verydefinite focal abnormality is found within the first 24hours from time of onset, brain neoplasm should besuspected.
Cerebral infarcts of about one inch or less indiameter do not visualize in a brain scan and,therefore, go undetected by this test. It is well es-tablished that a single abnormal brain scan confirmsthe existence of a focal brain lesion but gives nosignificant differential information concerning thepathology of the lesion.
Although this special procedure is safe, it isseldom necessary in making a differential diagnosis,adds considerable expense to the work-up of a patient,and has not in any way thus far replaced angiography.
Likewise, dynamic rapid serial scintigraphy usinga gamma camera, thus giving a serial display of theimages, provides much less precise information ofclinical significance than is available throughangiography. For instance, it is commonly impossibleto determine whether a carotid artery is occluded orwhether there is a severe degree of stenosis. Likewise,modest amounts of stenosis are generally missed bythis test and ulceration of an atherosclerotic plaque inthe internal carotid artery in the neck cannot bedetected. Large and small vessel occlusive disease in-tracranially is commonly missed by this method.
D. Roentgen examination1. Radiographs of the chestStandard radiographs of the chest give valuable
information concerning heart size and configuration,aortic pathology and pulmonary pathology, includinginfection and neoplasia.
2. Radiographs of the headPlain radiographs of the skull give significant
positive diagnostic information in relatively fewpatients with clinically typical occlusive cerebrovas-cular disease — cerebral infarction. However, com-mon practice almost dictates such films be obtained.Occasionally evidence of cranial trauma or an in-tracranial mass lesion may be detected. Calcificationof the carotid artery in the region of the sella is verycommon but does not give significant statisticalevidence concerning the presence or absence ofocclusive disease of a carotid artery at the place wherethe' calcification is noted.
3. Angiography (cranial)An important special procedure is cervical-
cerebral angiography. There are numerousangiographical techniques for visualizing cervical-cerebral vasculature. The most important item,however, has to do with the skill of the personnel andtheir total familiarity with the method they are using.It is now fully apparent that in almost every patientwhere angiography is indicated, entire cervical-
cerebral circulation should be visualized withtechnically first-rate films. It is still the practice insome institutions to get films that show only a portionof the cervical part of the circulation, and in some in-stances the films of the intracranial vasculature aretechnically so poor that no significant information isavailable from them. Films of all portions of thecervical-cerebral circulation are necessary to be cer-tain of the primary diagnosis as well as to ascertainwhether a second or even more lesions may be present.If any kind of surgical intervention is being planned, itis important that the surgeon know the state of thecollateral circulation and this can be obtained orevaluated only if fine films of all portions of thecervical-cerebral circulation are available.
Indications for angiography are:(1) Differential diagnosis of the brain pathology.
Even with careful attention to all the items listed un-der history, general examination, neurological ex-amination neurovascular examination and additionaltests, there still remain about 5% of patients whosediagnosis is uncertain. In such instances, cervical-cerebral angiography is the best method of making adistinction between vascular occlusive disease, an in-tracerebral expanding mass such as a hemorrhage,abscess or brain tumor, cerebral infarction and sub-dural hematoma, as well as demonstrating aneurysmsand arteriovenous malformations.
(2) Transient focal ischemic attacks — par-ticularly the carotid system. In such instancescervical-cerebral angiography should be performed ifthere are one or more than one of: amaurosis fugax,bruit over the beginning of the internal carotid artery,retinal emboli, unilateral decrease in retinal arterypressure or ischemic retinopathy. If none of these arepresent, the likelihood of finding a lesion accessible tothe surgeon is very small.
(3) Selected instances of vertebrobasilar TIAs.In some situations, it may be difficult to make aclinical distinction between the carotid and thevertebrobasilar system. If the TIAs are characteristicof those coming from the vertebrobasilar system,there is little merit to doing extensive angiography.
(4) Very early progressing stroke or very fre-quent TIAs in the carotid system with, as a part of thehistory, amaurosis, an appropriate bruit, retinal em-boli, etc.
(5) Many patients with subarachnoid hem-orrhage and some patients with intracerebral hemor-rhage.
An uncertain indication is a long systolic orsystolic-diastolic loud internal carotid artery bruit inpatients who are being scheduled for major generalsurgery. If there is prolonged hypotension or verysevere blood loss, the carotid stenosis may decreaseblood supply to a focal region of brain to a criticallevel of ischemia. Recent observations suggest thatsuch patients do not have an increased risk of stroke;therefore, arteriography is not necessary.
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Contraindications are advanced forms ofsystemic disease. Acute myocardial infarction, allergyto contrast media, etc., must be considered contrain-dications or relative contraindications to cervical-cerebral angiography. If the cerebrovascular diseasehas produced a situation where there is car-diorespiratory depression, coma, or extraordinarilysevere neurological deficit, angiography is not in-dicated.
E. Special procedures1. Computerized soft tissue tomography (e.g.,
currently abbreviated to CT, EMI scanner, ACTAscanner, etc.)
Computerized tomography equipment employs anarrow beam of x-rays to scan a patient's head in aseries of slices. The rays pass through the head and aredetected by two sensing devices which always pointtoward the x-ray source. Both the x-ray tube anddetector scan across the patient's head linearly andmultiple readings of x-ray transmissions through thehead are made during each traverse in the EMIscanner. At the end of each scan, the system is rotated1° and the process is repeated. This continues for 180scans when 28,000 readings will have been taken.These readings are then processed in a minicomputer,which calculates absorption values of the materialwithin the slice from the 28,000 simultaneousequations. From these calculations a three-dimensional picture or matrix is built which in essencedisplays differential x-ray "densities" inside the headin a way never before possible. The matrix for each"brain slice" is displayed on a cathode ray viewingunit and a numerical print-out is also produced. Theformer is photographed by a Polaroid camera.
The system is about 100 times more sensitivethan conventional x-ray systems and enables smallvariations in tissue density to be differentiated. Theskin area irradiated is confined to a narrow bandaround the edge of the slice and the dosage is ap-proximately equivalent to a conventional x-ray pic-ture.
The cerebral ventricles are accurately visualizedand there is good display of the subarachnoid spaces.Brain atrophy or any abnormality which alters ventri-cle size, configuration or position can be detected.
Extravasated blood has a density much greaterthan brain. A small focal hemorrhage is easilyvisualized and blood in the ventricles is easilydetected.
Nonhemorrhagic cerebral infarcts can be seen;within a few hours of onset, edema around the infarctmay be apparent. A very hemorrhagic infarct may bedifficult to differentiate from a hemorrhage; the latteroften has a rounded shape.
Brain tumors commonly can be distinguishedfrom cerebral infarcts or intracerebral hemorrhage.
Circulating blood is not displayed; intracranialaneurysms and arteriovenous malformations will notbe seen unless they contain clotted blood or calcium.
Subdural hematomas may be difficult tovisualize, particularly when they are bilateral and donot produce shift of the ventricles.
It is apparent that computerized tomography willrevolutionize the differential diagnosis of intracraniallesions.
2. Cerebral blood flow measurementsA variety of methods for measuring cerebral
blood flow have been devised in the last 25 years.None of the currently used methods are accurate,reproducible and noninvasive. The methods have beenused primarily in research and have provided informa-tion about cerebrovascular physiology. The most ac-curate techniques involve catheterization of the inter-nal carotid artery and/or jugular vein with attendantrisks. At the present time, these methods are notsignificantly helpful in clinical practice.
By numerous invasive techniques measurement ofjugular venous oxygen tension, jugular venous lactateconcentration, and arterial-jugular venous oxygendifferences may be carried out. The data providedhave occasioned much discussion but are not of signifi-cant value in the clinical care of patients with stroke.
3. Retinal circulation timeTen percent fluorescein is injected into an
antecubital vein and the time elapsing between the in-jection and the arrival of the dye in each retina isdetermined by ophthalmoscopic examination, usingspecial filters. The test is cumbersome (three peopleare needed; one to observe each retina and one to in-ject the fluorescein) and does not give enough uniqueinformation to make it worthwhile. Development ofappropriate devices for simultaneously photographingthe retina might make the test more practical.
4. Thermography and thermometryThermography (as relating to stroke) measures
the temperature (by recording infrared emissions fromthe skin) particularly over the mesial supraorbital areaof the forehead which is supplied by terminal branchesof the ophthalmic artery which originates from the in-ternal carotid artery. Sometimes occlusion or verysevere stenosis of the internal carotid artery isassociated with reduced skin temperature in this par-ticular area. The equipment is expensive and the testrequires several minutes. Because of the expense andgeneral cumbersomeness of the equipment, the testhas not become popular.
Thermistor recordings of temperature fromvarious points across the forehead give similar infor-mation to thermography. This testing technique hasnot been of enough practical value, particularly inreplacing other methods, to be useful.
A variety of thermochromic liquid crystals andpaints which detect small changes in temperature havebeen investigated but have not become useful prac-tically because of difficulties in their application com-pared to the value of the information obtained.
5. Retinal photographyIt is possible to photograph the retina in color
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and picture the changes of vessel occlusion, retinal in-farction, hypertensive disease, diabetes, hemorrhageand the various types of emboli. However, theprocedure is so cumbersome and expensive that it isnot practical for screening or in the diagnosis ofrelatively large numbers of patients.
6. Tilt-table studyLowering of the effective arterial perfusion
pressure to the brain by tilting the patient to an up-right position on a tilt-table has been suggested as away to induce transient focal cerebral ischemic at-tacks. Because it is ineffective in almost all instancesas well as requiring special equipment, the procedureis seldom used.
7. PhonocraniographyThe recording and/or transmission of bruits is
possible; the equipment and methods are not currentlysatisfactory for large-scale application of this method.
8. ElectronystagmographyThis is an electrical technique for recording
nystagmus and other eye movements. It is possible torecord nystagmus when the patient's eyes are closed.Therefore, the test is of value in recording caloricnystagmus which may be absent when the eyes areopen but present when the eyes are closed. However,thus far there is no significant differential informationabout cerebrovascular disease obtained by thistechnique. Further study of electronystagmographymay produce methods which make it of some clinicalusefulness.
9. Doppler blood flow estimationContinuous sonic energy has been used in an
(noninvasive) attempt to map the morphology of ex-tracranial arterial blood flow, i.e., carotids, supraor-bital vessels, etc. Thus far the method has notproduced satisfactory accurate results. Further refine-ment of the equipment may make this technique auseful one.
The technique involves carrying light into theskin of the face; change in intensity of light back-scattered from the skin is converted by a photocell tovoltage for polygraphical recording during each car-diac cycle. By recording the electrocardiogramsimultaneously, the interval from electrical ventricularsystole (the R-wave) until the arrival of the opacitypulse wave at the site monitored can be measured. It ispossible that further development of this instrumenta-tion may produce a useful technique for the screeningof patients with carotid occlusive disease.
This is a term commonly though incorrectly usedin referring to a measurement of the impedance of thehead to the passage of an electrical current which isapplied externally. Although this technique has beenunder study for over a decade, it has not appeared tobe of significant aid in the evaluation of stroke.
Part VI. Status of Patient (Performanceand Placement)INTRODUCTION
At many points in the natural history of stroke, it isdesirable to estimate the performance ability of thepatient. In this section, a classification of performanceability and placement potential is presented. Suchassessment of the status of the patient serves as asignificant guide to the course the disease process hastaken, the management effort required, and the selec-tion of a life-situation to which the patient can ap-propriately return. Ability of the patient to performsatisfying and productive activity in a supportive en-vironment is a result of many intrinsic and extrinsicfactors. Intrinsic factors may include such elements asthe degree of general and focal cerebral damage, theresidual neurological function, the integration ofadaptive and substitutive patterns of function, the pre-existing level of development of intellect and skill, anddeveloped attitudes and emotions. Extrinsic factorsare even more varied and numerous and include suchinfluences as the nature of the physical environmentand living arrangements, the degree of family involve-ment and support, interpersonal relationships, thesocial and economic resources, and even attitudes ofthe family, friends, potential employers and the com-munity at large. Prescription for continuing manage-ment in and outside of the health care facility must bebased on information derived in detail from allavailable clinical and social sources. Classification ofperformance and placement provides a grosscharacterization of what life-tasks the patient is ableto do and how he will be able to live.
PERFORMANCE
In the context used in this Classification, performanceis defined as the execution of set tasks. The design of atask can be structured in formal testing or can bevariably determined by environmental or situationalcircumstances of the life-setting. The nature of thetask determines the action to be taken by the patient.The patient must be able to recognize the demandsmade on him by the task, to select the appropriate ac-tion to accomplish the task and then to successfullycarry out the selected action. Because the broad rangeof life-situations sets innumerable variations of taskrequirement, only generally recognized descriptions ofperformance that are of key significance in the care ofthe stroke patient form the basis of this Classification.It is further recognized that performance in a test set-ting varies according to test conditions and socialsituations and may not necessarily predict perfor-mance in other social contexts such as in the house, atwork, or in the community at large. These con-siderations color but do not negate the value ofclassification by test and observation.
For purposes of this Classification, three descrip-tors of life-situations are selected as indices of perfor-mance status. These are: (a) activities of daily living
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(ADL), (b) avocational activities, and (c) occupationalactivities.
Activities of daily living (ADL) — a battery oftasks designed to provide an index of ability to per-form self-sustaining activities that meet personal re-quirements in each day's life-experience. These essen-tial activities are basic in everyone's day, relativelyindependent of geographical locale, physical environ-ment, or social situation. They include such commonactivities as dressing, washing, eating, and travelingfrom place to place; they involve fundamental actionsof body and limb movement, sitting balance, changingbody position, standing, reaching, grasping, holding,and the like.
Avocational activities — those active pursuits ofliving not directly related to one's primary life workfrom which the individual gains significant par-ticipatory, creative, or productive satisfaction. Theseare not essential requirements of everyday living buthave value in bringing purpose and fulfillment to theindividual, his family and circle of friends. They in-volve multifaceted behavior patterns and at timesemploy complex hierarchies of physical and mentalactivities. Avocational activities include such pursuitsas hobbies, travel, recreation, socializing and the like.
Occupation — the primary life-work to which theindividual devotes the major portion of time, skill,energy, thought and effort and from which the in-dividual derives role and status, physical and mentalsatisfaction, and economic support. In addition torecognized modes of remunerative employment, oc-cupation includes homemaking, student life, retire-ment and other primary life-pursuits. In thisClassification all such pursuits engaged in at the timeof onset of stroke are considered the primary occupa-tion.
PLACEMENT
The goal of care is ultimate return of the recoveredpatient to an optimal physical, mental, social,vocational and economic condition consistent with thepatient's remaining performance abilities and re-quirements for continued health maintenance.Suitable physical environment, living arrangements,and social, economic and health care support must beselected. Medical status, performance ability and con-ditions in available environmental settings arevariables that determine the placement status. Among
the critical considerations leading to optimal place-ment are the suitability of the architecture and sur-rounding environment, the kind and frequency of per-sonal supervision and direction required, and the levelof requirement for continuing medical-nursing care.Possibilities for placement vary widely but may in-clude placement in full competitive employment,placement in sheltered or selected work situations,resumption of homemaker duties, retirement from thework market, independent living in personal residencewith full management responsibility, home care withfamily supervision, home care with outside assistance,domiciliary care, convalescent care, custodial care, orcontinued rehabilitation center or hospital care.
Part VI. Status of Patient (Performanceand Placement)PERFORMANCE
Class I. No Significant Impairment — fullyindependent acts of daily living (ADL), pursues usualavocational activities, and returns to previous livingsite and occupation without modification.
Class II. Mildly Impaired — semidependent(requiring some assistance) in activities of daily living,and/or slight restriction of avocational activities,and/or able to return to previous occupation withsome modification of the latter.
Class III. Moderately Impaired — semidepen-dent (requiring lifting assistance) in activities of dailyliving, and/or considerable restriction of avocationalactivities, and/or unable to return to previous occupa-tion and must seek selective occupation.
Class IV. Severely Impaired — fully dependentin conduct of activities of daily living, and/or unableto participate in avocational activities, and/or unableto carry out any occupation.
PLACEMENT
Class A. No Limitation.Class B. Mild Limitation — requires occasional
supervision, and/or modified environment and/or oc-casional medical care.
Class C. Moderate Limitation — requires muchsupervision, and/or physical assistance or outsidehelpers and/or regularly available medical care.
Class D. Severe Limitation — requires constantor nearly constant attendance and/or immediatelyavailable medical-nursing care.
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C. General cerebral dysfunction1. Transient2. Prolonged
a. Acute onsetb. Gradual progression
II. Pathophysiological MechanismsA. Primary abnormalities of cerebral circulation (specify transient or persistent)
1. Thrombosis2. Embolism3. Hemorrhage (specify — See Anatomy and Pathology)4. Compression5. Vasospasm6. Direction of flow7. Alteration in rate and/or volume8. Dissection of arterial wall9. Associated with arteriography
B. Abnormalities of general circulation (specify transient or persistent)1. Hypotension (specify cause)2. Hypertension
C. Alterations in blood (specify type)D. Alterations of metabolic demand (specify type)E. Possible predisposing factors
1. Hypertensive disease2. Diabetes mellitus3. Cardiac disease4. Hyperlipidemia5. Other (specify)
F. UnknownIII. Anatomy
A. Blood vessels1. Arteries
a. Ascending aortab. Aortic arch
1) Brachiocephalic a. (innominate a.)2) Common carotid a. (specify r. or 1.)
a) External carotid a. (specify r. or 1.)b) Internal carotid a. (specify r. or 1.)
(a) Anterior communicating a.(5) Middle cerebral a.
3) Subclavian a. (specify r. or 1.)a) Vertebral a. (specify r. or 1.)
(1) Posterior inferior cerebellar a.b) Basilar a.
(1) Anterior inferior cerebellar a.
In several places in this condensed version of the Classification, the symbols used are changed from the complete Classification. This is to makepossible the use of the common items.
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1) Frontal lobe2) Temporal lobe3) Parietal lobe4) Occipital lobe5) Central white matter (specify by lobe)6) Internal capsule7) Thalamus
b. Brain stem1) Midbrain2) Pons3) Medulla oblongata
c. Cerebellumd. Cranial nerves (specify by number and r. or 1.)e. Cerebral ventricles (specify by name and r. or 1.)
3. Spinal cordIV. Pathology
A. Pathological alterations in vessels1. Arteries
a. Congenital, developmental and inherited lesions1) Congenital aneurysms2) Congenital aneurysm, ruptured
b. Inflammatory lesions (arteritides)1) Infectious2) Noninfectious
a) Cranial arteritis (temporal arteritis)c. Trauma and physical agents
1) Trauma to artery due to external forces2) Trauma due to angiography3) Trauma due to catheterization and other intra-arterial procedures4) Trauma due to surgery
d. Arterial lesions due to blood dyscrasiase. Arterial lesions associated with metabolic abnormalities (including familial
hypercholesterolemia, diabetes mellitus, etc.)f. Arterial lesions associated with drug toxicity, drug idiosyncrasy and unknown drug effects
1) Anticoagulants2) Other
g. Arterial embolism due to cardiac disease and diseases of extracerebral vessels1) Cardiac arrhythmias (specify basic disease)2) Valvular disease3) Myocardial infarction
h. Arterial lesions associated with neoplastic disease
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a. Congenital, developmental and inherited lesions1) Arteriovenous fistula, congenital2) Arteriovenous fistula due to ruptured congenital aneurysm3) Vascular malformations (hamartomas, angiomas)
B. Pathological alterations in brain1. Infarction (pale, hemorrhagic and mixed)
a. Without vessel stenosis or occlusionb. With arterial stenosis or occlusion associated with: (list as under Pathological alterations in
vessels, arteries — IV.A.l.)2. Hemorrhage
a. Without vessel type identifiedb. Of arterial origin (list as under Pathological alterations in vessels, arteries or use terms as
follows)1) Anatomical site
a) Intracerebral(1) With hypertension(2) Without hypertension
b) Subarachnoidc) Subdurald) Intraventricular
2) Etiology (specify)c. Of venous origin (specify)d. With capillary lesions [See IV.A.3.]e. With combined arterial, venous and capillary lesions [See IV.A.4.]
V. Clinical Phenomena (History, Physical Examination, Laboratory Examination, Roentgen Examination,Other)
A. History1. Demographic2. Family history3. Past history4. Present illness
CLASSIFICATION AND OUTLINE OF CEREBROVASCULAR DISEASES II
E. Special procedures [See Outline pp 610-611 for discussion]1. Computerized axial tomography (computerized tomography, computed tomography) [See Outline]2. Cerebral blood flow (specify method) (list results) (describe complications)3. Retinal circulation time (specify method and results) (fluorescein)4. Thermography and thermometry (specify method and results)5. Retinal photography (specify method and results)6. Tilt-table study (specify method and results)7. Phonocraniography (specify method and results)8. Electronystagmography9. Doppler blood flow estimation (specify method, site, results)
10. Ocular plethysmography (specify method and results)11. Cranial impedance plethysmography (rheoencephalography) (specify method and results)
VI. Status of Patient (Performance and Placement)Performance
Class I. No significant impairmentFully independent acts of daily living (ADL), pursues usual avocational activities, andreturns to previous living site and occupation without modification.
Class II. Mildly impairedSemidependent (requiring some assistance) in ADL, and/or slight restriction of avocationalactivities, and/or able to return to previous occupation with some modification of the latter.
Class III. Moderately impairedSemidependent (requiring lifting assistance) in ADL, and/or considerable restriction ofavocational activities, and/or unable to return to previous occupation and must seek selec-tive occupation.
Class IV. Severely impairedFully dependent in conduct of ADL, and/or unable to participate in avocational activities,and/or unable to carry out any occupation.
PlacementClass A. No limitationClass B. Mild limitation
Class C. Moderate limitationRequires much supervision, and/or physical assistance or outside helpers, and/or regularlyavailable medical care.
Class D. Severe limitationRequires constant or nearly constant attendance and/or immediately available medical-nursing care.
The World Federation of Neurology Code for Grading AtherosclerosisGrade 1+: Opacity involving only a small part of the vessel circumference. No lumen narrowing.Grade 2+: (A) A diffuse thin plaque that does not involve the entire vessel circumference with minimal lumen
narrowing. (B) A small thick plaque that produces less than 25% lumen narrowing.Grade 3+: (A) A diffuse thin plaque involving the entire circumference of the vessel with mild lumen narrow-
ing. (B) A localized thick plaque producing 25% to 50% lumen narrowing.Grade 4+: (A) A thick plaque involving the entire circumference of the vessel with moderate or marked lumen
narrowing (pipestem). (B). A localized thick plaque resulting in more than 50% lumen narrowing.
Wagener and Keith Classification of Retinal Vascular DiseaseGroup I: Retinal changes are minimal and consist of mild narrowing and mild sclerosis of arterioles.Group II: Changes are somewhat more advanced; patient's general health is good.Group III: Pronounced abnormality of small retinal vessels and small artery may be obstructed; there are
definitely localized narrowed areas in the retinal vessels, hemorrhages and exudates. May have mild alteration ofvision.
Group IV: Similar to Group III but with florid hemorrhages, retinal edema and sometimes swelling of thenerve head. Visual impairment is present and neurological symptoms are common.
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