Parkinsonism with organophosphate poisoning.

Parkinsonism is a primary neurotoxic manifestation of organophosphate pesticide intoxication. We report here the case of a 67-year-old man who developed acute parkinsonism with tremors and rigidity following exposure to fenitrothion, an organophosphate pesticide. His parkinsonism disappeared, and 2 months later he was able to walk alone without antiparkinsonian drug treatment. To identify particular lesions in the brain, Z score images were obtained from SPECT (single photon emission computed tomography) scans of the patient during the acute poisoning and a follow-up scan performed 2 months later. We indicate that reversible parkinsonism correlated with putaminal hyperperfusion as observed in the Z score images obtained during the acute event; this condition resolved later in concert with resolution of the clinical parkinsonism. We believe that the SPECT scan Z score images in this study are an important find in elucidating parkinsonism manifestations due to organophosphate poisoning.