Assessment of brain stem dysfunction in a comatose patient
When examining a comatose patient, one should be aware of signs and symptoms indicating that the coma is due to brain stem (reticular formation) dysfunction.
This is especially true of impending brain stem failure from increased intracranial pressure causing herniation into the posterior fossa.
This dysfunction travels in a rostral caudal direction, ending in death with medullary involvement.
Emergency management to reduce the intracranial pressure should be implemented immediately. The following observations are used to monitor the patient’s condition:
- Mental status
- Oculovestibular test of gaze response to ice-water calorics
- Breathing pattern
- Pupillary size and light response
- Motor response to supraorbital nerve pressure (noxious stimulus)
- Spontaneous eye movement or deviation
- Oculocephalic reflex on head turning (doll’s eye movement)
- Presence of other brain stem reflexes (corneal, gag, and ciliospinal)