Prevalence of neuroleptic-induced restless legs syndrome in patients taking neuroleptic drugs.

Dopamine deficiency or dopamine dysfunction has been implicated as one of the factors involved in the pathophysiology of restless legs syndrome (RLS). Our objective is to determine the prevalence of primary RLS in patients taking neuroleptic drugs. One hundred patients taking neuroleptic drugs and 100 healthy age- and sex-matched controls were interviewed with the Cambridge-Hopkins diagnostic questionnaire for RLS. Patients with malignancy, end-stage renal disease, neuropathy, history of spinal cord diseases, pregnancy and Parkinson's disease were excluded. Only one patient had symptoms consistent with RLS (1%), similar to one patient in the control group. She was a 40 years old female with a diagnosis of depression. She started having RLS symptoms approximately four years after starting perphenazine. The symptoms persisted after the medications were discontinued but decreased in severity and frequency. Her serum ferritin level was 90.3 ng/ml. The prevalence of primary RLS is low in patients attending the out-patient clinic who are taking neuroleptic drugs. Other factors apart from dopaminergic dysfunction are likely to be involved in the pathogenesis of RLS.