BARBITURATE INTOXICATION: A CLINICAL ELECTROENCEPHALOGRAPHIC STUDY *

IN the process of recording from a large number of patients admitted to this hospital in comatose states, it has been observed that individuals rendered unconscious by barbiturate drugs present a remarkably homo-geneous EEG pattern. This pattern can be clearly differentiated from the recordings obtained in comatose states induced by all other agents and pathophysiologic mechanisms that have come under our observation. The characteristic EEG pattern of barbiturate intoxication consists of a random frequency high voltage type. Slow waves occur in isolated and short sequences of sinusoidal 160 to 250 millisecond waves and in non-sinusoidal (or complex sinusoidal) slower discharges at around 300 milli-seconds in duration. These latter waves often have higher frequency oscilla-tions superimposed. The higher frequency waves occur in two main bands; the first ranges between 12 and IS waves per second and the second ranges around 18 to 24 per second. The randomly admixed waveforms of rela-tively high voltage give the general pattern an irregular modulation