Criteria for brain death contain three essential elements :-Widspread cortical destruction that is reflected by deep coma and unresponsiveness to all forms of stimuli (absence of motor activity). Global brainstem damage demonstrated by absent papillary light reaction and by the loss oculovestibular and corneal reflexes. Destruction of medulla demonstrated of complete apnea.Absent EEG and pupillary dilatation are seen in brain death, However they are not included in the clinical criteria for brain death diagnosis.