The patient must be in deep coma with no spontaneous movements,
with the possible exception of spinal reflexes. The cause of the coma
must be established and should be sufficient to account for the loss of
brain function, as is seen with, for example, massive intracranial
hemorrhage or cranial trauma. The corneal, gag, cough,
oculocephalic (commonly called “doll’s eyes”) and oculovestibular
reflexes need to be absent. In order to test the oculocephalic reflex,
the head must be rotated to one side; in brain death, the eyes stay
fixed in their sockets. In deep coma with an intact reflex, the eyes do
not turn to the opposite side when the head is turned; instead, they
stay where they were and slowly “right” themselves to the midline.
This may be thought of as a “righting” reflex.