The Electro-encephalogram in Chronic Post-traumatic States.

THE electro-encephalographic changes following a recent head injury have been described (Williams, 1941). The observations were made upon 74 cases of head injury selected from a total of 600 because the injury had occurred less than 20 days previously. From these observations it was concluded that the electro-encephalogram (e.e.g.) accurately reflects the abnormal cerebral state caused by a recent head injury, that the progressive changes are a direct indication of improvement or deterioration in this state, and that in the milder degrees of cerebral dysfunction it may demonstrate residual damage after all clinical signs have subsided. As symptoms may persist long after full recovery from a head injury might reasonably be expected the whole series of cases was used to observe the subsequent changes in the e.e.g. after the acute effects of the injury had subsided. It is the purpose of this paper to record the results and to relate them to some of the etiological causes of the chronic post-traumatic syndrome.' Material