Cyanide-induced parkinsonism: a clinicopathologic report.

An 18-year-old man ingested 975 to 1,300 mg of potassium cyanide in a suicide attempt. He was treated and survived the poisoning episode, but then had severe parkinsonian syndrome, characterized primarily by akinesia and rigidity. He died 19 months after the drug overdose. At autopsy, major destructive changes were found in the globus pallidus and putamen, whereas the melanin-containing zone of substantia nigra was intact. This is the first clinicopathologic report of parkinsonism as a result of cyanide poisoning.