Simultaneous recording of pupillary hippus and EEG. Report of a case.

Pupillary hippus was observed and recorded in a man of 44 years, who had epileptic seizures, chronic alcoholism with liver disease and Primidon intoxication, during a period of unconsciousness of 24 h. During this time the simultaneous records of the EEG and pupillogram over a long period of time revealed that the basic EEG rhythm and hippus had the same frequency. Both recordings were temporarily in phase, time-locked, and could be blocked by painful and acoustic stimuli. The etiology and interpretation of hippus are discussed.