Recorded EEG rhythms within the alpha-frequency band, paradoxically resembling waking patterns but in apparently comatose patients, a pattern termed alpha coma, have been reviewed over a 10 yr period in the Division of Electroencephalography, University of Washington School of Medicine, Seattle, WA. Of 50 patients with records showing the alpha-pattern coma, 49 were admitted with cardio-pulmonary arrest and one had developed alpha coma with hyperglycemic, hyperosmolar coma. In addition to the alpha activity, arrhythmic delta waves were present diffusely in 25% and theta waves in 23%. The outcomes of patients with or without alpha coma after cardiac arrest did not differ significantly, the majority not regaining consciousness and dying in hospital. The single patient with hyperglycemic coma regained consciousness and was discharged but did not fully recover cognitive function. A review of the literature did not preclude neurological recovery following alpha coma. 
COMMENT: Alpha coma usually follows cardiac arrest and can be identified in 25% of patients. It also follows brainstem lesions, sedative drug overdose, respiratory arrest, and severe disturbance of glucose metabolism. Where alpha coma follows a condition other than cardiac arrest or a brain stem lesion the outcome is usually good. The prognosis is especially favorable after drug overdose.