Coma Exam

Coma Exam

Consciousness impaired from:

·       Damage to brainstem reticular formation

·       Bilateral lesions of the thalami

·       Bilateral lesions of the cerebral hemispheres

Mental Status

·       Document the patient’s level of alertness with a specific statement of what the patient did in response to particular stimuli – helps chart progress

Cranial Nerves

·       Ophthalmoscopic exam (CN II) – look for papilledema

·       Vision (CN II): blink-to-threat observes if patient blinks in response to moving hand rapidly toward their eyes from different directions

·       Pupillary responses (CN II, III):

o   unilateral blown pupil - transtentorial herniation

o   bilateral small but responsive pupils -  pontine lesions

o   bilateral pinpoint pupils – opiate overdosage

·       Extraocular Movements (CN III, IV, VI, VIII)

·       Oculocephalic reflex

o   hold patient’s eyes open and rotate head from side to side

o   present if the eyes move in the opposite direction of the head movements (doll’s eyes)

o   presence suggests brainstem dysfunction when comatose

·       Caloric Stimulation

o   With patient supine and head elevated at 30˚, infuse ice water into ear

o   If brainstem vestibule-ocular reflex intact, nystagmus will occur with the fast phase directed opposite the side of cold water infusion

o   COWS (cold opposite, warm same)

·       Corneal reflex, facial asymmetry, grimace response (CN V, VII)

·       Gag reflex (CN IX, X) – lightly touch the posterior pharynx on each side with a cotton swab

Sensory and Motor Exam

·       Spontaneous movements – test each limb for withdrawal from painful stimulus, such as nail bed pressure or skin pinch

·       Withdrawal from a painful stimulus

Reflexes

·       Deep tendon reflexes

·       Plantar response

·       Posturing reflexes

o   Decorticate – brainstem transected above the red nuclei

o   Decerebrate – brainstem transected below red nuclei

·       Special reflexes in cases of suspected spinal cord lesions

Brain Death

·       Irreversible lack of brain function

·       Exact criteria is hospital dependent

·       Must be no evidence of brain function including brainstem

·       Neurologic, caloric and apnea tests are administered

·       Apnea test – lack of spontaneous respirations without the ventilator must be demonstrated despite certain standard changes in blood pH or pCO2