Irresistible onset of sleep during acute levodopa challenge in a patient with multiple system atrophy (MSA): placebo-controlled, polysomnographic case report.

A 67-year-old male patient with clinically probable multiple system atrophy developed severe reproducible sleepiness and irresistible onset of sleep during an acute levodopa (L-dopa) challenge. In a placebo-controlled, double-blind study of acute L-dopa challenge, videopolysomnography revealed multiple episodes of non-rapid eye movement sleep 60 minutes after L-dopa and none following placebo. These observations suggest the irresistible sleep can also be induced by L-dopa and also in patients with atypical parkinsonism.