Less pronounced intensity of extrapyramidal hyperkineses and aggravation of motor disturbances in patients with diffuse sclerosis occurring under the effect of tegretol prompted the authors to study the action of this drug on the course of experimental allergic encephalomyelitis. Daily administration of tegretol in a dose of 375 mg/kg retarded the development of the affection and produced a marked adynamia in the animals. Slowing down of the dominant rhythm and depression of its amplitude were recorded on the EEG. Shifts in the potassium and sodium content and reduced brain cholesterase activity were noted. The authors ascribe these changes to a mediated action of tegretol upon deep-seated cerebral structures.