Etiology and Neuropathophysiology of Coma

Abstract

Awareness and wakefulness require an intact connection of the neocortex with the ascending reticular formation. Any factor disrupting these pathways is likely to cause a syndrome of unconciousness. Disorders of consciousness encompass a broad spectrum of different entities with coma being the most severe form of unresponsiveness. Awareness and wakefulness are completely absent in coma and there is no detectable sleep-wake cycle. The etiology of coma is constituting a long list; unilateral mass lesions compressing the contralateral hemisphere could as well be responsible as drugs or toxins leading to diffuse bilateral cortical damage. In this article specific causes of coma will be discussed and their likely pathophysiological mechanisms outlined.