Relationship of periodic leg movements and severity of restless legs syndrome: A study in unmedicated and medicated patients

• Published in: Clinical neurophysiology Vol. 118; no. 7; pp. 1532 - 1537
• Main Authors: Hornyak, Magdolna, Hundemer, Hans-Peter, Quail, Deborah, Riemann, Dieter, Voderholzer, Ulrich, Trenkwalder, Claudia
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.07.2007; Elsevier Science
• Subjects: Arousal - physiology; Biological and medical sciences; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Dopamine Agonists - therapeutic use; Double-Blind Method; Female; Fundamental and applied biological sciences. Psychology; Humans; IRLS; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Nocturnal Myoclonus Syndrome - drug therapy; Nocturnal Myoclonus Syndrome - physiopathology; Pergolide - therapeutic use; Periodic leg movements; Polysomnography; Restless legs syndrome; Restless Legs Syndrome - drug therapy; Restless Legs Syndrome - physiopathology; Severity; Sleep - physiology; Sleep. Vigilance; Vertebrates: nervous system and sense organs; Restless legs syndrome; IRLS; Severity; Periodic leg movements; Polysomnography; Human; Sensitivity disorder; Nervous system diseases; Evaluation scale; Idiopathic; Lower limb; Sleep disorder; Electrodiagnosis; Sleep; Treatment; Arousal; Placebo; Sleep wake cycle; Neurological disorder; Peridoc leg movement
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2007.04.001

Abstract Objective To evaluate the relationship of the severity of restless legs syndrome (RLS) as assessed by a subjective, patient-rated scale (International RLS Study Group Rating Scale, IRLS), and of periodic leg movements in sleep (PLMS) as an objective parameter, in two different patient populations. Methods Data of 200 unmedicated patients with idiopathic RLS were evaluated. Group 1 ( n = 100) consisted of selected patients participating in the Pergolide European Australian RLS (PEARLS) study. Group 2 ( n = 100) represented an outpatient RLS population investigated in a Sleep Disorders Center. Additionally, Group 1 was also evaluated after a 6 week double-blind treatment period, where 47 patients received pergolide and 53 patients placebo. Results In unmedicated patients, IRLS scores correlated with the PLMS-arousal index ( r = 0.22, p = 0.033) but not with the PLMS index in Group 1 while no correlation was found in Group 2. The change of the IRLS score under treatment in Group 1 correlated significantly both with the change of the PLMS index ( r = 0.42, p < 0.001) and the change of the PLMS-arousal index ( r = 0.38, p < 0.001). Conclusions The IRLS adequately reflects treatment changes of PLMS indices. In unmedicated patients, the IRLS correlates with PLMS indices probably only in selected RLS populations with predefined PSG criteria and high PLM activity. Significance The IRLS is an appropriate subjective rating scale for measuring treatment effects in RLS.