Pathogenesis 1. Cerebral hemodynamic alteration 脑血流重分布 Initial changes: redistribution of circulation ( diving reflex)→> cerebral blood flow↑ Continue insult: loss of vascular autoregulation, systemic hypotension, cerebral blood flow cerebral ischemia1. Cerebral hemodynamic alteration： 脑血流重分布 Initial changes：redistribution of circulation (diving reflex) → cerebral blood flow↑ Continue insult：loss of vascular autoregulation, systemic hypotension, cerebral blood flow↓ cerebral ischemia Pathogenesis