Examination of the unconscious patient. Reviewed and revised 30 March 2015. OVERVIEW. Coma. Coma is a state of unconsciousness caused by temporary or permanent impairment of the ascending reticular system in the brainstem, or both cerebral hemispheres. Describe the history of brain death. (Caloric) reflex. Brain Death Neurological. testing contralateral TM. Oculovestibular TENTH EDITIONATLS ® Advanced Trauma Life Support® Student Course Manual New to this edition ATLS. May 20, 2013…