ASSESSMENT OF CONSCIOUS LEVEL
1-THE STATE OF CONSCIOUSNESS
DEPEND ON (RAS ) FROM THE
BRAIN STEM TO THE THALAMUS
2-THE CONTENT OF CONSCIOUSNESS , ARE,
A- (AWARNESS)
OF THE PERSON DEPENDS ON
CEREBRAL CORTEX, THALAMUS AND CONNECTIONS
.
The ascending reticular activating system( ARAS)
believed to be integrated to induce and maintain
alertness.
It originate in the (tegmentum )of the upper pons and
midbrain ,connects to the thalamus and the
hypothalamus then to the cerebral cortex.
Consciousness as a state of awareness of self and surroundings .
in consciousness are conceptualized into two types :
1. Cognitive and mental function
,ex dementia, delusions .
2. Arousal ex alert, stupor or coma .
Alert refers to a perfectly normal state of arousal.
Attention is the ability to focus on specific stimuli.
Confusion is the inability for clear and coherent thought and speech.
Lethargy lies between alertness and stupor.
Stupor is a state of baseline unresponsiveness that requires
repeated application of vigorous
stimuli to achieve arousal.
Coma is a state of complete unresponsiveness to
arousal, in which the patient lies with the eyes closed .
The terms lethargy and stupor cover are subject to
misinterpretation when used without further qualification .
Coma
1-Unarousable unresponsiveness .
2-Medical or surgical emergency.
Cause of coma into three groups:
1. structural lesions.
2. metabolic and toxic .
3. Psychogenic.
APPROACH TO TH2E PATIENT IN COMA
1-History.
2-General examination .
3-Neurological examination.
Decorticate posturing is bilateral flexion at the elbows
and wrists, with shoulder adduction and extension of the
lower extremities.
It is a much poorer localizing posture, usually above the
brainstem.
Note Multiple myoclonus suggest a metabolic or toxic cause
Decerebrate posturing is bilateral extensor posture,
with extension of the lower extremities and
adduction and internal rotation of the shoulders
and extension at the elbows and wrist.
Bilateral midbrain or pontine lesions below the
red nucleus.
Rapid Initial Examination and Emergency
1-Rule out the need for immediate medical or surgical
intervention .
2-Empirical use of supplemental oxygen, intravenous
thiamine
(at least 100 mg), and intravenous 50% dextrose in water
(25 g).
Investigations
Basic labs , ABG’s ,electrolytes, TFT , drug and toxin
screening , serum osmolarity.
ECG.
Brain images.
LP.
EEG.
Prognosis
1-Diseases causing structural damage, such as
cerebrovascular disease carry the worst prognosis;
2-Coma from hypoxia-ischemia due to causes such as
cardiac arrest has an intermediate prognosis;
3-Coma due to hepatic encephalopathy and other
metabolic
causes has the best ultimate outcome
The longer duration of coma the worse the prognosis.
The prognosis worsens with increasing age in traumatic
coma but does not appear to be predictive of recovery
in nontraumatic coma .
1-Delerium
Delirium is by far the
1-most common behavioral disorder in a medical-surgical
setting.
In general hospitals, the prevalence ranges from 15% to
24% on admission.
2-The incidence ranges between 6% and 56% of
hospitalized patients, 11% to 51% postoperatively in elderly
patients, and 80% or more of intensive care unit (ICU)
patients .
Clinically
1-Acute onset of mental status change with fluctuating course.
2-Attentional deficits .
3-Confusion or disorganized thinking.
4-Perceptual disturbances , illusions and hallucinations
5-Disturbed sleep/wake cycle excessive day time drowsiness
and reversal of the normal diurnal rhythm. “Sundowning”—with
restlessness and confusion during the night.
Delirium
Altered level of consciousness .
Altered psychomotor activity .
Disorientation and memory impairment .
Visuospatial abilities and writing .
Behavioral and emotional abnormalities.
Delirium
many terms used to describe this disorder:
1--acute confusional state,
2-altered mental status,
3-acute organic syndrome,
4--acute brain failure, acute brain syndrome,
5-acute cerebral insufficiency,
exogenous psychosis, metabolic encephalopathy, organic
psychosis, ICU psychosis, toxic encephalopathy, toxic
psychosis, and others.
MENINGEAL irritation
1-Neck stiffness ,Kerning sign
2-Brudzinski sign
3-Kernig sign
Disorder of the motor system
Upper motor neuron
Lower motor neuron
Stance and Gait
Depend on,
Visual
Sensory
Corticospinal ,extrapyramidal ,cerebellar
pathways
Lower motor neuron
Spinal reflexes
Stance ,tests
1- Cerebellar ataxia with eyes open
2-Romberg test with eyes closed
(sensory ataxia ) (proprioceptive sensory loss in the legs)
Gait ,
Abnormal Gait
1-shuffling gait,
2-central ataxia (wide based gait) –cerebellar
disease
3-Sensory ataxia –wide based gait with positive
Romberg test in neuropathy and spinal cord
disorders
4-Spastic gait ---spinal cord disease
5-Hemiplegic gait---UMN
6-Scissor gait bilateral UMN
7-Waddling gait
8-bizarre gait
Speech
Dysartheria
Dysphasia
Dysphonia
Dyslaxia
Dysartheria
1-perephral cause (Denture)
2-Pseudobulbar palsy(bilateral UMN)
(Dysartheria,brisk Jaw Jerk,emotional lability)
3-Bulbar palsy (bilateral LMN)
4-Cerebellar Dysartheria—slurred speech
5-Fatiguing speech—Myasthenia gravis
6-parkinsonism speech --low volum,monotonous voice
(dysphonia,dysartheria)
Dysphonia
Vocal cord disease or—xnth cr N –bovine
( ineffective cough)
Dysphasia
1-Expressive (motor)Dysphasia—Broca area
(non-fluent speech and grammar errors)
(comprehension is intact)
2-receptive Dysphasia Wernick area
(poor comprehension),meaningless fluent speech
Incorrect words,
3-Global Dysphasia –arcuate fasciculus combination of
expressive and receptive Dysphasia
4-Nominal Dysphasia difficult naming)
5-dyslexia—(difficulty comprehending written language
and writing impairment (Dominant parietal lobe lesions )
Higher cortical functions,
Mini-mental test
Thinking , Emotion , behavior , planning, movement initiation, perceiving sensory informations
Functional organization of the nervous system
The nervous system is divided into the following
parts according to the function of that part :
Higher cortical function
Dominant side
Frontal lobe
Function-----personality, Emotional response,
Social behavior
Lesion
Disinhibition,lack of initiative,antisocial
behavioue,incontinence,impaired memory,Grasp
reflexes
anosmia
A-
Anteriorhalf
of the cerebral hemisphere
deals with executive functions of the
human brain
B-Posterior half of the cerebral
hemispheres deals with the
perception of the environment .
Fontal lobe
Posterior part—motor strip(precentral gyrus)
Higher cortical function
Braim lobes
Dominant side
Frontal lobe
Functions-----
personality,
Emotional response,
Social behavior,
expressive language,
frontal eye field centre
,micturition centre
Lesion
Apathy or Disinhibition,
lack of initiative,
antisocial behaviour, urinary incontinence,
impaired memory, Grasp reflexes
Anosmia, loss of emotional respomsivness,
emotional lability
(Cognitive impairment eg 1- memory, 2-attention
and 3-concentration,) dysphasia (domininant), focal motor seizers (motor strip)
Parietal lobe
Dominant lobe --
contains the
1-post-central gyrus(sensory strip)
2-anterior part (principle destination of conscious
sensation),
3-the upper fiber of the optic nerve
, calculation, language, planned
movements
appreciation of size—shape ---weight—texture
Lesion
Dyscalculia, dysphasia, dyslexia, apraxia,
agnosia, Homonymous hemianopia,
cortical sensory impairment,
focal sensory seizer(postcenral gyrus)
Non-domionant lobe
Spacial orientation, constructional skills
Lesion
Neglect of non- dominant side,
spatial disorientation,
constructional apraxia,
Dressing apraxia,
Homonymous hemianopia
Temporal lobe
Dominant lobe—
Auditory perception, Speech, Language, Verbal
memory, Smell
Lesion
Dysphasia, Dyslaxia, poor memory,
complex hallucination(smell,sound,vision,),
Homonymous hemianopia
Non-Dominant lobe
Auditory perception,
music ,
tone sequence,
Non verbal memory(face,shape,music),
smell
Lesion
Poor non-verbal memory.
loss of music skill,
complex hallucination,
Homonymous hemianopia
Occipital lobe
Analysis of vision
LESION
Homonymous hemianopia,
Impaired face recognition
Visual hallucination (light , line zig-zag)
Mini Mental State Examination(MMSE)
1-orientation to time.place,person
Time y,season,date,day,,month=5 points
2-registration—name 3 objects—3 point
3-Attention and calculation
Serial 9
Recall----3point name obgect
4-Language 3p0int
