by students of kims amalapuram

1. APPROACH TO THE PATIENT

2.  Acute respiratory and cardiovascular problems
should be attended prior to the nuerological
assesment
 In most instances a complete medical
evaluation except for vital signs,fundoscopy
may be deffered until the nuerological
evaluation has established the severity and
nature of coma

3. HISTORY
 The cirucmstances and rapidity with which
nuerological symptoms developed
 The antecedent symptoms
(confusion,headache,seizures,dizziness,doubl
evision)
 The use of medications,drugs,alcohol
 Chronic liver,kidney,lung,heart or other medical
diseases

4. General Examination

5.  Alterations in vital signs (temperature, pulse,
respiratory rate, and blood pressure) are
important in diagnosis
 FEVER-suggests systemic infection,bacterial
meningitis,heatstroke,neurolepticmalignant
syndrome,malignanthyperthermia
 Hypothermia-is observed in patients with
alcohol,barbiturate, sedative,or phenothiazine
intoxication,hypogycemia,peripheral circulatory
failurehdddddddddde important aids in
diagnosis.

6.  Marked hypertension suggests hypertensive
encephalopathy or cerebral hemorrhage or
headinjury
 Hypotension is characterstic of coma from
alcohol or barbiturate intoxication,internal
hemorrhage,MI,sepsis,profound
hypothyroidism or addissonian crisis

7.  Pulse:
 Bradycardia-brain tumors,opiates
 Tachycardia-hyperthroidism,uremia
 Patient present with Hypertension with
bradycardia occurs in response to increased
ICP and signs of cerebral herniation

8.  Multiple bruises (particularly a bruise or boggy
area in the scalp), bleeding, CSF leakage from
an ear or the nose, or periorbital hemorrhage
greatly raises the likelihood of cranial fracture
and intracranial trauma
 Marked pallor suggests internal hemorrhage
 Cutaneous petechiae suggests thrombotic
thrombocytopenic purpura, meningococcemia
or bleeding diathesis assosciated with an
intracerebral hemorrhage

9.  Cyanosis and reddish or anemic skin
colouration are other indications of an
underlying systemic disease or
carbonmonoxide as responsible for coma

10.  The odor of the breath may provide a clue to
the etiology of coma.
 The spoiled-fruit odor of diabetic ketoacidotic
coma, the uriniferous odor of uremia, the
musky and slightly fecal fetor of hepatic coma,
and the burnt almond odor of cyanide
poisoning

11.  Fundoscopic examination can detect sub
arachonoid hemorrhage,hypertensive
encephalopathy,and increased intracranial
pressure

12. NEUROLOGICAL EXAMINATION

13.  Tossing about in the bed ,reaching up towards
the
face,crossinglegs,yawning,swallowing,coughin
g, moaning reflect a DROWSY state
 Lack of restlesness movements on one side or
an outturned leg suggests hemiplegia

14.  Intermittent twitching movements of foot,
finger,or fascial muscle may be only sign of
seizures
 Multifocal myoclonus almost alaways indicates
a metabolic disorder, particularly uemia,anoxia
drug intoxication
 In a drowsy and confused patients bilateral
asterixis is a sign of metabolic
encephalopathy or drug intoxication

15.  Decorticate rigidity and Decerebrate rigidity, or
"posturing," describe stereotyped arm and leg
movements occurring spontaneously or elicited
by sensory stimulation.
 Flexion of the elbows and wrists and supination
of the arm (decortication) suggests bilateral
damage rostral to the midbrain, whereas
extension of the elbows and wrists with
pronation (decerebration) indicates damage to
motor tracts in the midbrain or caudal
diencephalon.

17.  The less frequent combination of arm extension
with leg flexion or flaccid legs is associated with
lesions in the pons.
 These concepts have been adapted from animal
work and cannot be applied with precision to
coma in humans.
 In fact, acute and widespread disorders of any
type, regardless of location, frequently cause
limb extension, and almost all extensor posturing
becomes predominantly flexor as time passes.

18. LEVEL OF AROUSAL
 A sequence of increasingly intense stimuli is
used to determine the threshhold for arousal
and the motor response of each side of body
 The results of testing may vary from minute to
minute and serial examinations are useful
 Tickling the nostrils with a cotton whisp is
moderate stimulus to arousal-all but deeply
stuporous amd comatose patients will move
the head away and arouse to some degree

19.  Noxious stimuli such as pressure on
knuckles,bony prominences
,pinprickstimulation, pinching skin to arousal in
further step-abduction avoidance movement of
a limb is usually purposeful and denotes an
intact corticospinal system
 Posturing indicates severe damage to the
cortico spinal system

20. GLASGOW COMA SCALE

21. Newer Scales for Prognosis of
Coma:
 FOUR (Full Outline of UnResponsiveness) SCALE
 New Coma Scale is devised in 2005, Four
components (Eye, Motor, Brainstem, Respiration)
 Each component has maximum of score of Four.
 AVPU
 Alertness, response to Verbal stimuli, response
to Painful stimuli, or Unresponsive
 ACDU
 Alertness, Confusion, Drowsiness,
and Unresponsiveness
 Grady Scale
 Scale of I to V along a scale of Confusion, Stupor,
Deep stupor, abnormal Posturing, and Coma.

22. BRAINSTEM REFLEXES
 Assessment of brainstem function is essential
to localization of the lesion in coma.
 The brainstem reflexes that are conveniently
examined are pupillary size and reaction to
light, spontaneous and elicited eye
movements, corneal responses, and the
respiratory pattern

23.  As a rule, coma is due to bilateral hemispheral
disease when these brainstem activities are
preserved, particularly the pupillary reactions
and eye movements.
However, the presence of abnormal brainstem
signs does not always indicate that the primary
lesion is in the brainstem because
hemispheral masses can cause secondary
brainstem pathology by transtentorial
herniation.

25. OCULAR MOVEMENTS
 In light coma of metabolic origin, the eyes rove
conjugately from side to side in seemingly
random fashion, sometimes resting briefly in a
eccentric position. These movements
disappear as coma deepens, and the eyes
then remain motionless and slightly exotropic.
 The eyelids may remain tonically retracted
because of failure of levator inhibition in some
cases of pontine infarction (eyes-open coma)

26.  There is persistent conjugate deviation of the
eyes to one side—away from the side of the
paralysis with a large cerebral lesion (looking
toward the lesion) and toward the side of the
paralysis with a unilateral pontine lesion
(looking away from the lesion).
 The eyes turn down and inward with
hematomas or ischemic lesions of the
thalamus and upper midbrain

27.  "Ocular bobbing" describes brisk downward and
slow upward movements of the eyes
associated with loss of horizontal eye
movements and is diagnostic of bilateral
pontine damage, usually from thrombosis of the
basilar artery.

28.  Ocular dipping" is a slower, arrhythmic
downward movement followed by a faster
upward movement in patients with normal
reflex horizontal gaze; it indicates diffuse
cortical anoxic damage.

29. OCULOCEPHALIC REFLEX

30.  Oculocephalic reflexes (doll’s-eye movements)
are elicited by briskly turning or tilting the
head.
 The eye movements in the direction opposite
to the head movement ,depend on the integrity
of ocular motor nuclei and their
interconnecting tracts extend from midbrain to
pons and medulla

31.  The ability to elicit them therfore reflects both
reduced cortical influence on the brainstem
 Intact brainstem pathways indicating that
lesion is is caused by lesion in cerebral
hemispheres
 An absence of reflex eye movements usually
signifies damage within the brain stem but
can also results from overdoses of certain
drugs

33.  The test is performed by irrigating the external
auditory canal with cool water in order to
induce convection currents in the labyrinths.
 After a brief latency, the result is tonic
deviation of both eyes to the side of cool-water
irrigation and nystagmus in the opposite
direction.

34.  Absence of nystagmus with preserved
conjugate deviation: Cerebral hemisphere
damage
 Absence of conjugate movement: Brainstem
lesion

35. CORNEAL RESPONSES
 By touching the cornea with a whisp of cotton ,
a response consists of brief bilateral lid closure
is usually observed
 The corneal reflex depends on the integrity of
pontine pathways between the 5th and 7th
cranial nerves in conjuction with reflex eye
movements it is useful test to pontine function

36. RESPIRATORY PATTERNS
 Shallow, slow, but regular breathing
suggests metabolic or drug depression.
 Rapid, deep(Kussmaul)breathing seen in
metabolic acidosis,pontomesencephalic
lesions.
 Cheyne-Stokes respiration, signifies
bihemispheral damage/bilateral thalamic
lesions or metabolic suppression and
commonly accompanies light coma

37.  Apneustic breathing is characterized by a long
inspiratory pause, after which the air is
retained for several seconds and then
released. This abnormality appears with
lesions of the lateral tegmentum of the lower
half of the pons.
 Agonal gasps are lower brainstem (medullary)
damage and are well known as the terminal
respiratory pattern of severe brain damage

38. LABORATORY STUDIES AND
IMAGING
 The studies that are most useful in the
diagnosis of coma are: chemical-toxicologic
analysis of blood and urine, cranial CT or MRI,
EEG, and CSF examination.
 Arterial blood gas analysis is helpful in patients
with lung disease and acid-base disorders

39.  The metabolic aberrations commonly
encountered in clinical practice require
measurement of electrolytes, glucose, calcium,
osmolarity, and renal (blood urea nitrogen) and
hepatic (NH3) function.

40.  The availability of CT and MRI has focussed
on attention on cause of coma that are
detectable by imaging (hemmorhage,tumor or
hydrocephalus)
 The notion that a normal CT scan excludes
anatomic lesion as the cause of coma is
erroneous.

41.  Bilateral hemisphere infarction, acute
brainstem infarction, encephalitis, meningitis,
mechanical shearing of axons as a result of
closed head trauma, sagittal sinus thrombosis,
and subdural hematoma isodense to adjacent
brain are some of the disorders that may not
be detected.
 Nevertheless, if the source of coma remains
unknown, a scan should be obtained.

42.  The EEG is useful in metabolic or drug-
induced states but is rarely diagnostic.
 It is essential test when coma is due to
clinically unrecognized,non convulsive seizure,
and shows fairly characterstics patterns in
herpesvirus encephalitis, or to prion
(Creutzfeldt-Jakob) disease.

43. LUMBAR PUNCTURE
 Examination of the CSF remains
indispensable in the diagnosis of meningitis
and encephalitis. For patients with an altered
level of consciousness, it is generally
recommended that an imaging study be
performed prior to lumbar puncture to exclude
a large intracranial mass lesion.