REM sleep behavior disorder predisposed by neuroleptic malignant syndrome: a case report

A 44-year-old man was confirmed by polysomnography to have rapid eye movement (REM) sleep behavior disorder (RBD) following recovery from haloperidol- and risperidone-induced neuroleptic malignant syndrome (NMS). RBD symptoms persisted for 30 days. Subsequently, no clinical symptoms or polysomnographic findings of RBD have been observed for 3 years. RBD is reported to be associated with Parkinson’s disease and dementia with Lewy bodies, which involve brainstem dopaminergic hypofunction. However, no reports have documented RBD due to drug-induced dopaminergic hypofunction. This appears to be the first observation of RBD in relation to pharmacological dopaminergic dysfunction.