Criteria for Brainstem death includes:

Brainstem death is defined by the absence of all brainstem mediated cranial nerve reflexes. Pupillary Light Reflex is a brainstem mediated cranial nerve reflex that is absent in brainstem death. The pupils are usually midsized but may be dilated (should not however be small). Occulo-cephalic (Doll&;s eye) reflex and Vestibulo-ocular (Caloric) reflex are both brainstem mediated cranial nerve reflexs that should be absent in Brainstem death. Criteria for Brain Death/Brainstem death The definition of Brain stem death requires simultaneous demonstration that the patient has irreversibly lost the capacity of consciousness (Coma) and the capacity to breathe (Apnoea) both of which are dependent on intact brainstem. Clinical assessment of the integrity of Brainstem has two components including assessment of the integrity of brainstem mediated cranial nerve reflexes and the Apnea test. REF: Harrison book of internal medicine 21ST EDITION