We have presented a partial review of the literature dealing with encephalographic studies of groups of epileptics, together with a summary of our experience with encephalography in 286 institutionalized epileptic patients. From our studies we believe that we may draw the following conclusions:1. Encephalography is a valuable and relatively safe procedure in the study of epileptic patients.2. The value of this procedure has been considered from the standpoint of diagnosis, prognosis, and treatment.A. There is no lesion characteristic of epilepsy as revealed by encephalography. The structural changes revealed by this method cannot be differentiated with regard to etiologic agent, nor from similar changes in non-epileptic individuals. These changes in themselves are not an essential part of the convulsive disorder, but may be regarded as concomitant or as a result of the same process giving rise to the epileptic manifestations. Encephalography has revealed the presence of lesions in some patients which were not indicated from the history or by the physical and neurological examinations. The relatively frequent occurrence of incomplete drainage and failure of the ventricles to fill with air in the symptomatic groups may indicate that this phenomenon may be of more significance as evidence of abnormality than was formerly believed.B. The most valuable aspect of encephalography is that of prognosis. The presence of irreversible changes in structure is convincing evidence that often little can be done for the patient other than to render his existence as comfortable as possible.C. Encephalography is of little value as a therapeutic measure in epilepsy. Only 2 of 122 patients showed complete remission from seizures for a 6-months' period. A relatively small number were improved, a slightly larger number made worse, and the greatest number unchanged. We know of no way by which patients may be selected for the therapeutic effect of this procedure.Abstract Teaser