Acute methyl iodide exposure with delayed neuropsychiatric sequelae: report of a case

Methyl iodide is a monohalomethane used as an analytic and organic chemistry reagent, as a methylating agent in organic chemical synthesis, and as a fumigant. In an acute exposure, methyl iodide is a pulmonary and dermal irritant. Chronic neurotoxicity has been reported in survivors of acute exposure.

A review of the 11 case reports of methyl iodide poisoning in the medical literature of the 20th century found that six of the patients experienced a chronic neurological syndrome characterized primarily by delayed psychiatric, behavioral, and cognitive sequelae.

The case patient experienced a massive exposure to methyl iodide with resulting life-threatening burns. During convalescence, various cognitive and behavioral deficits became apparent. The results of a comprehensive evaluation at our occupational toxicology clinic, which included sequential neuropsychometric testing, are described.

The findings in the case patient may advance our understanding of the mechanisms and clinical manifestations of chronic neurotoxicity after exposure to methyl iodide.