Systematic EEG follow-up study of traumatic psychosis.

A systematic 2 year follow-up study of EEG in 100 patients suffering from traumatic psychosis with amnesia lasting more than 1 week led to the following results. (1) EEG foci were demonstrated in 95% of cases, and bilaterally in 70%. Normalization occurred within 3 months in 48% of patients, with foci persisting for more than 2 years in 22% mostly in patients with traumatic epilepsy. Focal signs initially consisted of delta foci (85%) and finally of focal dysrhythmia (72%), with temporal localization increasing from 58% to 82%. EEG foci were associated with neurological focal symptoms in 49% of cases and skull fractures in 78%. (2) During psychosis a general slowing of EEG was constantly observed. Normalization occurred within 3 months in 28% of patients. Rarely slowing lasted longer than 6 months. (3) It took longer to normalize general slowing than EEG foci, but slowing disappeared more completely. The left preponderance of EEG foci in traumatic psychosis could not be confirmed, the hypothesis of a pathoplastic role of the speech dominant hemisphere was not proved.