Localized EEG abnormalities in acute carbon monoxide poisoning.

The EEG of a patient with acute carbon monoxide poisoning was characterized by lateralized sharp waves and a focal electrographic seizure discharge within hours of the exposure. These findings were associated with coma and focal motor seizures. The patient made a full clinical recovery, and the EEG was normal two months after the exposure. The association of a primarily diffuse cerebral insult after CO poisoning, with prominent lateralized epileptiform discharges in the EEG, is a distinctly unusual phenomenon.