Classification of coma.

By order of the Head Injuries Committee of the W.F.N.S. the author and his coworkers give definitions of consciousness, clouding of consciouness and unconciousness or coma. Furthermore, they suggest a definition of the termination of unconsciousness, with particular reference to the transition into a stage of clouding of consciousness. Any statistical evaluation and comparison of different materials depend on the use of identical definitions. As an example, it has been shown that the duration of aa uninterrupted coma, which can be survived, becomes relatively short if in accordance with the proposed definitions the various stages of clouding of consciousness are excluded from "coma".