J. Neurol. Neurosurg. Psychiat., 1964, 27, 241

Primary spontaneous cerebrospinal fluid rhinorrhoea'JOHN E. A. O'CONNELL

From St. Bartholomew's Hospital, London

The adjective 'spontaneous' as applied to cerebro-spinal fluid rhinorrhoea simply indicates that thedischarge is not an immediate or delayed result oftrauma. Cases of spontaneous cerebrospinal fluidrhinorrhoea can be subdivided into two distinctgroups, secondary and primary. In the secondarygroup an obvious cause for the leak is present.This -may be some gross lesion producing erosion ofthe skull base; examples of such lesions are osteo-mata of the nasal sinuses, intracranial neoplasms,particularly pituitary adenoma and craniopharyn-gioma, and internal hydrocephalus due to neoplasticor other cause; the lesion may be a meningocele oror meningo-encephalocele, the rhinorrhoea at timesfollowing attempts to treat the swelling by an intra-nasal operation. In the primary group no cause forthe leak of cerebrospinal fluid can be found, and it iswith this group ofunknown aetiology that the presentcommunication is concerned.As is the case in all medical problems, so in that of

cerebrospinal fluid rhinorrhoea adequate knowledgeof the relevant anatomy and physiology is essentialif abnormalities are to be recognized and under-stood. In the second century Galen had observed thefluid in the ventricles of the brain and considered it awaste product to be excreted via the pituitary intothe nose. Vesalius and the other great anatomists ofthe middle ages also mentioned the fluid and in theseventeenth and eighteenth centuries Willis andCotugno studied it. Probably it was the publicationof the results of his researches, carried out over aperiod of 15 years, by Magendie in 1842 that con-tributed most to a general understanding of theanatomy and physiology of the cerebrospinal fluid.The post-traumatic discharge of fluid from the nosehad been described by Bidloo the elder (quoted by StClair Thomson, 1899) in the seventeenth century. Thefirst description of what was certainly spontaneouscerebrospinal fluid rhinorrhoea was given by Millerin 1826. He gives the history of a boy with a progres-sively enlarging head who developed a recurringdischarge of fluid from his nose and in whom a largeinternal hydrocephalus was revealed at necropsy;

'A paper read at the combined meeting of the Neurosurgical Societyof America and the Society of British Neurological Surgeons inLondon in June 1963.

the route by means of which the fluid reached thenose from the cranium was also recognized, anopening to the right of and anterior to the cristagalli. In 1899 St Clair Thomson reviewed theliterature dealing with spontaneous cerebrospinalfluid rhinorrhoea up to that date, describing 21cases, including one of his own. The reports reviewedhad appeared between 1834 and 1898. Study of thesecase records suggests that in possibly nine therhinorrhoea was of unknown aetiology; in the othersevidence of a lesion to which the leak was secondaryappears undoubted. Johnston in 1926 reviewed 21cases reported before that date and after the publica-tion of St Clair Thomson's monograph. In eight ofthese the rhinorrhoea appeared to be a primary one.Coleman and Troland (1947) collected another 12examples of the primary type and added threepersonal cases. Before 1954 other reports of one ortwo cases of cerebrospinal fluid rhinorrhoea withno apparent cause had been presented by Wessels(1939, one case), Adson (1941, one case), Love andGay (1947, two cases), Cloward and Cunningham(1947, one case), and Rand (1953, two cases). Thismakes a total of only 39 cases reported before 1954.No doubt this list of published cases is incompleteand others have been added in the last 10 years. Itseems likely, however, that the number of casesreported to date is less than 75.

All those who have studied the subject of primarycerebrospinal fluid rhinorrhoea have given thoughtto two particular problems: first the force responsiblefor the escape of the fluid. and secondly the route bywhich it enters the nose. Concerning the force res-ponsible, Coleman and Troland considered it un-known, but other authors (St Clair Thomson,Johnston, Locke, Love and Gay, Rand) haveregarded raised intracranial pressure, long-continuedor transient but recurring, to be an essential feature.In discussing the route of entry of cerebrospinalfluid into the nose, St Clair Thomson suggested aspossibilities a small intranasal meningocele, a com-munication between subarachnoid space and nasallymphatics, or an imperceptible opening in the cribri-form plate. Johnston suggested a persistent cranio-pharyngeal duct as a possible channel but Locke (1926)considered that the openingwas invariably in thecribri-

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form plate. Coleman and Troland thought that thefluid spread along the arachnoid sheaths of the olfac-tory nerves, while Rand believed that a dysplasiaof either the developing cartilaginous cribriformplate or of the meninges related to the olfactorynerves caused a fistula through which a leak becameestablished.Two personal cases of primary spontaneous

cerebrospinal fluid rhinorrhoea will now be de-scribed.

CASE REPORTS

CASE 1 Mrs. O.B., aged 42, a housewife and mother offour children, was referred by Dr. K. Latter and admittedon 3 December 1954, complaining of a discharge fromthe right nostril. This had begun 15 months previously.There had been no preceding head injury, nor was theonset of the discharge related to any form of heavyphysical exertion. At first the clear fluid escaped as a dropevery five minutes, but the flow increased graduallyuntil on bending forwards the dripping was continuouswith intervals of a few seconds between drops. The patientbecame aware of a salty taste in her mouth and wasoccasionally awakened at night by the accumulation ofthe fluid in her throat. Her only other symptoms were amild retro-orbital headache and a deterioration of hersense of taste and smell. There was nothing of significancein her past or family history.Examination revealed a healthy looking woman with

but two abnormalities on general physical and neurologicalexamination; first a colourless watery discharge from the

FIG. 1 a.

right nostril when the head was flexed (the drops wereseparated by an interval of some 10 seconds and escapedmore rapidly during jugular compression); secondlythere was a severe bilateral reduction in the sense of smell.Examination of the nasal discharge showed a proteincontent of 20 mg., chlorides 760 mg., and glucose 75 mg.per 100 ml. with no cells. Other laboratory investigationsrevealed no abnormality. The Wassermann reaction wasnegative. Skull films were normal; there was no fracturenor any abnormality of the cribriform area (Figure 1).The diagnosis was thus one of spontaneous cerebrospinalfluid rhinorrhoea of unknown aetiology.At operation a coronal incision was made and the scalp

flap reflected anteriorly, a bifrontal block of bone beingelevated (Figure 2). The dura mater was incised at theanterior limit of the exposure and the sagittal sinus dividedbetween ligatures. The right frontal lobe was elevatedfrom the floor of the anterior fossa and no suggestionof a dural tear or old fracture was seen. A loose arachnoidfold was present along the medial and inferior margin ofthe lobe and passed onto the superior aspect of the rightolfactory bulb. No such arrangement of the arachnoidwas present on the left side. When this fold of arachnoidwas divided it was seen (Fig. 2) that the olfactory bulbhad atrophied in its anterior half beneath the area ofattachment of the fold, and exposed on the cribriformplate was a punched-out circular dural opening throughwhich a 1 mm. probe could be passed into the nasalcavity. The olfactory bulb and anterior tract were excisedand a patch of temporal fascia sutured to the basal durato cover the whole of the cribriform plate and its immedi-ate environment. After suture of the dural incision thebone block was replaced and the wound closed. Post-

FIG. I b.

FIG. la and b. Skull films of case 1.

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Primary spontaneous cerebrospinal fluid rhinorrhoea

FIG. 2. Sketch to demonstrate the appearances at operationin case 1.

FIG. 3a.

operatively the rhinorrhoea stopped immediately andthere has been no recurrence. The patient has a rightanosmia but the sense of smell has perhaps improved onthe left. Five years later the patient was delivered of ababy son and remains in perfect health at the present time(May, 1963).

CASE 2 Mr. K.A., aged 44, a Negro machinist, wasadmitted on 28 May 1962, being referred by Dr. AldrenTurner because of a copious watery discharge from hisleft nostril. He stated that some six months previously hehad had a clear discharge from his nose for a couple ofdays. There was no further discharge until seven weeksbefore admission when it recurred and persisted. Its onsetwas not associated with injury to the head or physicalexertion. The discharge was copious and when he laydown he was conscious of the fluid running into thepharynx. He stated that eight years previously he hadbeen involved in a lorry accident; although the driverwas killed he had not himself sustained any head or otherinjury. For a few years he had suffered from grand malepilepsy and shown a personality change. Theie were noother symptoms and the family history contributednothing.On examination he was alert and cooperative. On

tilting his head forward there was a rapid discharge ofclear fluid from the left nostril, its rate being increasedby jugular compression. Neurological examinationshowed no abnormality apart from a possible reduction ofthe sense of smell. Examination of the nasal dischargerevealed that it was cerebrospinal fluid. On generalexamination the only abnormality was an irregularlyrecurring pyrexia associated with a 16,000 leucocytosis(930% polymorphs). Both the fever and the leucocytosissubsided with penicillin therapy. The cerebrospinal fluidobtained at lumbar puncture showed no abnormality, theprotein being normal. The Wassermann reaction wasnegative in the blood and cerebrospinal fluid and otherlaboratory investigations were also negative. Skull films

FIG. J b.

FrI. 3a and b. Skull films of case 2.

showed no abnormality other than an opacity of the leftethmoid and maxillary sinuses, possibly due to cerebro-spinal fluid within them (Figure 3). Pneumoencephalo-graphy showed no evidence of an internal hydrocephalusor tumour in the sellar region or elsewhere. The diagnosiswas considered to be one of spontaneous cerebrospinalfluid rhinorrhoea of unknown aetiology and explorationwas decided upon. A left frontal osteoplastic flap wasmade and the frontal lobe elevated without revealingany adhesions between it and the orbital roof or anteriorsphenoidal region, the sella and both optic nerves beingvisualized. It was noted that a loose funnel of arachnoidpassed forward around each olfactory tract (Figure 4).The left tract was divided and excised with the olfactorybulb, revealing a round opening in the cribriform platethrough which a fine probe could be passed into the nose.The further abnormality now noted was that the cribri-form plate was situated at the bottom of a deep cleftbetween the falx and crista galli medially and the stronglyarched orbital roof laterally. A piece of temporal muscle

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FIG. 4. Sketch to demonstrate appearances at operationin case 2.

was plugged into this cleft onto the cribriform plate. Thesame congenital abnormality on the right side was dealtwith similarly and then the whole area on both sides of themidline covered with a sheet of temporal fascia which wassutured in position. The wound was then closed. Post-operatively a small leak of cerebrospinal fluid was notedon several occasions over a few days. This then ceasedand there has been no recurrence. One year post-operative by the patient continues to have occasionalepileptic attacks but is otherwise entirely well.

DISCUSSION

The anatomical relationship between the subarach-noid space and the nasal cavity is a close one. Thethin cribriform plate of the ethmoid is coveredsuperiorly by dura mater and inferiorly by olfactorymucosa. In the photomicrograph reproduced inFig. 5 it will be seen that the measurement from theinternal surface of the dura mater to the nasal surface

,~~~~~~~~~^ Q ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.X..... ..........;..gI.... .....-M t 9 6 w Y S U~~~~~~~~~~~~~~~A ;-

FIG. 5. Photomicrograph of sec-tion through lamina cribrosa. Eachsmall division on the scale measuresone hundredth of a millimetre.

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of the mucosa is 0-85 mm.; correction for shrinkageoccasioned by fixation would suggest that themeasurement would be 1 1 mm. The cribriform plateis pierced by 10 to 20 olfactory nerves en route fromthe olfactory mucosa to bulb. Each of these nerves issurrounded by a prolongation of dura mater whichfuses inferiorly with its epineurium; within the duralsheath is an arachnoid prolongation fusing inferiorlywith the pial sheath of the nerve. There is thus aprolongation of the subarachnoid space into, and attimes through, the foramina in the lamina cribrosaand it seems probable that the tissue barrier betweensubarachnoid space and nasal cavity is frequently buta fraction of a millimetre in thickness.The possibility that, as a normal physiological

process, cerebrospinal fluid drained through thecribriform plate into the nose was accepted by Willisthough denied by Vieussens. Later the animalexperiments of Schwalbe (1869), of Key andRetzius (1875), and of Weed (1914) revealed thatfine particles injected into the subarachnoid spacepassed into the nasal submucosa and thence tolymphatic vessels. It is generally accepted thatcerebrospinal fluid is absorbed by this route. Le GrosClark (1929) demonstrated that dye injected into thenasal cavity of rabbits entered the cranium along theolfactory nerves and indeed it has been thought thatthis may be the route by which certain infectionsreach the nervous system.

It is clear that the anatomical relationship betweenthe subarachnoid space and the surface of the bodyis more intimate at the lamina cribrosa than at anyother situation. It might perhaps be expected that,in the absence of gross disease, the thin barrierbetween the cerebrospinal-fluid-filled spaces on theone hand and the nasal cavity on the other couldat times prove inadequate, and a communicationbetween the two become established, cerebrospinalfluid rhinorrhoea resulting. Normally the superiorsurface of the cribriform plate is entirely covered bythe olfactory bulb. The inferior surface of the frontallobe is closely applied to the floor of the anteriorfossa and to the olfactory bulb and the weak spot onthe cranial floor is thus well covered. However, thecovering may at times be defective. Thus in case 1 theanterior half of the olfactory bulb had atrophied andthe corresponding area of the cribriform plate layat the bottom of a funnel of frontal lobe arachnoidadherent around its margins (Figure 2). In thisexposed area was a rounded opening through whicha probe could be passed into the nose. It is believedthat for some reason atrophy of a portion of theolfactory bulb occurred here as the primary event,and that the pressure of the cerebrospinal fluid onthe exposed lamina cribrosa was the factor leadingto distention of the meningeal pouch in an empty

FIG. 6. Sketch to demonstrate anatomy of the fistula incase 1.

neural foramen and the eventual establishment of afistula (Figure 6). In case 2 two abnormalities werenoted. First a loose funnel of arachnoid passedforwards around each olfactory tract and onto thebulb, an arrangement quite different from the usual,in which the arachnoid closely invests the tract andbulb (Figure 4). Secondly there was a deformity ofthe skull base which resembled that noted at opera-tion in at least four of 10 cases of spontaneouscerebrospinal fluid rhinorrhoea recorded in theliterature since 1939. This deformity consisted in thepresence of a deep narrow cleft between the stronglyarched orbital roof laterally and the crista galli and

IFuro O7oter _

O/foctory bulbooChnoldmater

Olfoctory nerve,

FIG. 7. Sketch to demonstrate the anatomy of the fistulain case 2.

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falx medially, with the olfactory bulb sunken on itsfloor (Figure 7). It is suggested that the deformityremoved the olfactory bulb and tract from pressurefrom the overlying frontal lobe and that their arach-noid sheath therefore remained widely open. As aresult, a wide subarachnoid cistern lies upon thesuperior surface of the lamina cribrosa and prolonga-tion of this, the arachnoid sheaths of the olfactorynerves, are distended by the normal cerebrospinalfluid pressure. Secondary enlargement and intranasalrupture of one of these nerve sheaths would occasioncerebrospinal fluid rhinorrhoea.

It is not believed that raised intracranial pressureis necessary for the development of primary spon-taneous cerebrospinal fluid rhinorrhoea. The normalpressure of the fluid is positive in many positions ofthe head. Further, it is subject to recurring fluctua-tions. Observation of the fluctuations in intraventri-cular pressure (O'Connell, 1953) showed recurringrhythmic fluctuations of cerebrospinal fluid pressureaveraging 80 mm. cerebrospinal fluid every Awseconds. These observations have more recentlybeen checked using an electromanometer and asimilar average total recurring variation in pressureconfirmed. It is believed that the deep excavations ofthe cranial vault which are occupied by arachnoidgranulations are produced by the cerebrospinalfluid pulse. When this pulse gains access to the laminacribrosa it could also produce erosion of tissue hereand as a result cerebrospinal fluid rhinorrhoea isestablished spontaneously.

SUMMARY

Cases of spontaneous cerebrospinal fluid rhinorrhoeaare classified into primary and secondary grouips, andthe literature is reviewed. Two personal cases aredescribed. A hypothesis to explain the occurrence ofprimary spontaneous cerebrospinal fluid rhinorrhoeais put forward.

I am indebted to the Department of Medical Illustration,St. Bartholomew's Hospital, for the drawings of Mr. P.Cull, and for the photographs of the radiographs byMr. Tredennick. I must also express my gratitude toDr. B. Smith and Dr. Gordon Canti for the preparationand examination of the sections of the cribriform area.

REFERENCES

Adson, A. W. (1941). Proc. Mayo Clin., 16, 385.Cloward, R. B., and Cunningham, E. B. (1947). J. Neurosurg., 4, 519.Coleman, C. C., and Troland, C. E. (1947). Ann. Surg., 125, 718.Johnston, W. H. (1926). Ann. Otol (St. Louis), 35, 1205.Key, A., and Retzius, J. (1875). Studiens in der Anatomie des Nerven-

systems und des Bindgewebes (Stockholm).Le Gros Clark, W. E. (1929). Ministry of Health Reports on Public

Health and Medical Subjects No. 54. H.M. Stationery Office,London.

Locke, C. E. (1926). Arch. Neurol. and Psychiat. (Chic.), 15, 309.Love, J. G., and Gay, J. R. (1947). Arch. Otolaryng., 46, 40.Magendie, F. (1842). Recherches physiologiques et cliniques sur le

liquide cephalo-rachidien ou c6rebro-spinal. Mequignon-Marvis, Paris.

Miller, C. (1826). Trans. med.-chir. Soc. Edinb., 2, 243.O'Connell, J. E. A. (1953). Brain, 76, 279.Rand, R. W. (1953). Bull. Los Angeles neurol. Soc., 18, 74.Schwalbe, Schultze's Arch. II. s. 87. Centrlbl. & Med. W. 1869.Thomson, St Clair (1899). The Cerebro-spinal Fluid; its spontaneous

escapefrom the nose. Cassell, London.Weed, L. H. (1914). J. med. Res., 31, 21, 51, 93.Wessels, A. (1939). Ann. Otol. (St. Louis), 48, 528.

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