A Polysomnographic Study on Periodic Limb Movements in Patients with Restless Legs Syndrome and Neuroleptic-induced Akathisia

Eighteen patients with restless legs syndrome (RLS) and 4 patients with neuroleptic-induced akathisia (NIA) underwent all-night polysomnographic recordings before and during clonazepam treatment. Ten normal control subjects and 4 non-akathitic psychiatric patients treated with neuroleptics underwent polysomnographic recordings, which were compared with those of the RLS and NIA patients, respectively. Daily treatment with 0.5 to 3 mg clonazepam improved subjective complaints of 17 out of 18 patients with RLS and all the 4 patients with NIA. All the 18 patients with RLS exhibited periodic limb movements (PLM) on the polysomnograms before treatment, but only 2 of 10 control subjects exhibited PLM. Three of the 4 patients with NIA exhibited PLM, but none of the 4 controls on neuroleptics showed PLM. Clonazepam decreased the total number of PLM per hour in patients of both RLS and NIA.