Electroencephalographic studies of the encephalopathies; report of a nonfatal case of arsenical "hemorrhagic encephalopathy" with serial EEG studies.

"HEMORRHAGIC encephalopathy" during arsenical therapy for syphilis was comparatively rare until the advent of rapid treatment methods, several years ago. The incidence of this complication was reviewed by Glaser, Imerman and Imerman, 1 who pointed out that the mortality rate in this complication was 76 per cent. Dorothy Russell, 2 Scheinker 3 and others have noted that the cognomen "hemorrhagic" is really a misnomer and that perivascular necrotic phenomena may be the only notable feature present, rather than the outpouring of red cells. Engel 4 and his associates, in their studies on delirium, have emphasized the importance of serial electroencephalograms in the evaluation of the degree of clinical and anatomic recovery. In their investigation of a case of acute arsenical encephalopathy they stressed the degree of change in the electroencephalogram, rather than the appearance of any particular wave frequency. Their method was essentially one of quantitative analysis, in which they