Electroencephalographic findings in coma caused by fatal chloroquine poisoning.

A 19-year-old patient in deep anoxic coma after cardiopulmonary arrest due to suicidal acute overdosage of chloroquine was resuscitated at the intensive care unit. An EEG starting about 12 hours later and lasting for 93 minutes showed a rapid succession of diffuse ectopic rhythms, diffuse slow output, generalized periodic slow waves in paroxysmal episodes which preceded burst suppression patterns and definite establishment of electrocerebral silence. All these EEG patterns indicating a poor prognosis were registered about three hours before the patient died during irreversible ventricular fibrillation.