Toxic encephalopathy due to ingestion of bismuth salts: clinical and EEG studies of 45 patients.

Forty-five patients taking bismuth subnitrate orally for therapeutic reasons were admitted to hospital with a myoclonic encephalopathy of acute onset. The clinical features were similar, mostly with mental confusion, disorder of walking and standing, dysarthria, and myoclonic jerks. In 31 cases the EEG showed a characteristic pattern, not previously recognised, which assisted differential diagnosis.