Coma and confusional states: emergency diagnosis and management.

Coma and confusion signal a failure of brain function with many possible causes. Since many of the potential causes may quickly lead to death or severe disability, it is important to develop a focused and ordered approach to facilitate the rapid diagnosis and early institution of proper therapies. This requires an understanding of the localizing features of the neurologic examination and of the syndromes likely to cause coma and confusion, a predetermined plan for empiric therapies in certain cases of doubt when diagnostic confirmation will be delayed, and a careful consideration of cases when the diagnosis is not revealed by the initial neuroimaging, lumbar puncture, or EEG.