Parkinsonism induced by carbon monoxide intoxication: A “hidden gem” in the neurological literature

Parkinsonism can be acquired by various toxic exposures, among them carbon monoxide. Since the publication of a 1972 report of Parkinsonism associated with repeated episodes of carbon monoxide exposure, the medical literature has recorded multiple cases. A distinctive bilateral change in a specific brain region, the globi pallidi, provides strong evidence for carbon monoxide-induced Parkinsonism. In addition to acute intoxication with carbon monoxide, more chronic environmental exposures may also increase the risk for Parkinsonism. Paradoxically, recent research suggests that exposure to low-dose carbon monoxide might actually have a protective effect against Parkinson disease - but this needs to be carefully and safely tested.