EVIDENCE ON THE PERIODIC MECHANISM IN HERPES-SIMPLEX ENCEPHALITIS

A [human] case of herpes simplex encephalitis is described in which the EEG was recorded 5 times between the 5th day of illness and death on the 13th day. Repetitive discharges occurred at intervals of 3.5 or 2 s; at first they were larger and earlier on the right side, finally on the left; on day 11 they could be earlier on either side and sometimes ceased briefly on either side. They were associated with jerks. This periodicity cannot be explained by cortical isolation or a single pacemaker and hence favors a 3rd possibility, a more or less diffuse disturbance of the time constant of excitability at the cellular level.