Restless Legs Syndrome Probably Induced by Risperidone Treatment

Background: According to some reports, patients treated with risperidone may develop akathisia. Restless legs syndrome (RLS), which shares some clinical features with akathisia, is a distinct movement and sleep disorder that may be induced by various drugs that act on the CNS. Methods: We studied a 31-year-old patient suffering from a schizoaffective disorder including auditory hallucinations who developed symptoms typical of the RLS during treatment with risperidone, using polysomnography to objectify sleep disturbances and associated periodic leg movements during sleep (PLMS). Results: After switching from clozapine to risperidone treatment, the patient complained about dysethesias primarily of the legs, an urge to walk around, and sleep disturbances. The latter could be confirmed by polysomnography, including an abnormal PLMS index. Risperidone was switched to haloperidol. However, RLS symptoms were still present. After switching to quetiapine, RLS symptoms vanished and a second polysomnography test demonstrated better sleep quality and normal PLMS measurements. During the whole treatment period with different neuroleptics, the patient additionally received valproic acid. Conclusions: Symptoms typical of RLS may be induced by risperidone treatment and should be differentiated from akathisia. Although polysomnography is not necessary, it may be helpful confirming the diagnosis.

References

• 1 Atlas Task Force of the American Sleep Disorders Association, Guilleminault C. Recording and scoring leg movements.  Sleep 1993 16: 748-759
• 2 Ehrenberg B, Eisensehr I, Walters A S. Influence of valproate on sleep and periodic limb movements disorder.  Sleep Research. 1995;  24 224
• 3 Kraus T, Schuld A, Pollmächer T. Periodic leg movements in sleep and restless legs syndrome probably caused by olanzapine.  J Clin Psychopharmacol. 1999;  19 478-479
• 4 Montplaisir J, Boucher S, Poirier G, Lavigne G, Lapierre O, Lesperance P. Clinical, polysomnographic, and genetic characteristics of restless legs syndrome: a study of 133 patients diagnosed with new standard criteria.  Mov Disord. 1997;  12 61-65
• 5 Montplaisir J, Lorrain D, Godbout R. Restless legs syndrome and periodic leg movements in sleep: the primary role of dopaminergic mechanisms.  Europ Neurol. 1991;  31 41-43
• 6 Rechtschaffen A, Kales A. A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. Washington, DC: US Government Printing Office, Public Health Service 1968
• 7 Richelson E J. Receptor pharmacology of neuroleptics: relation to clinical effects.  J Clin Psychiatry. 1999;  60 (10) 5-14
• 8 Rosebush P I, Mazurek M F. Neurologic side effects in neuroleptic-naive patients treated with haloperidol or risperidone.  Neurology. 1999;  52 782-785
• 9 Rothdach A, Trenkwalder C, Haberstock J, Keil U, Berger K. Prevalence and risk factors of RLS in an elderly population: the MEMO study.  Neurology. 2000;  54 1064-1068
• 10 Walters A S, Hening W, Rubinstein M, Chokroverty S. A clinical and polysomnographic comparison of neuroleptic-induced akathisia and the idiopathic restless legs syndrome.  Sleep. 1991;  14 339-345
• 11 Walters AS and the International Restless Legs Syndrome Study G roup. Toward a better definition of the restless legs syndrome.  Mov Disord. 1995;  10 634-642
• 12 Wetter TC and Pollmächer T. Restless legs and periodic leg movements in sleep syndromes.  J Neurol. 1997;  244 S37-S45
• 13 Wetter T C, Stiasny K, Winkelmann J, Buhlinger A, Brandenburg U, Penzel T. et al . A randomized controlled study of pergolide in patients with restless legs syndrome.  Neurology. 1999;  52 944-960