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


CONCLUSIONS
The IRLS is an appropriate subjective rating scale for measuring treatment effects in RLS.
Hornyak
Magdolna
M
Department of Psychiatry and Psychotherapy, University Medical Center, Freiburg, Germany. magdolna_hornyak@psyallg.ukl.uni-freiburg.de
Hundemer
Hans-Peter
HP
Quail
Deborah
D
Riemann
Dieter
D
Voderholzer
Ulrich
U
Trenkwalder
Claudia
C
D001143:Arousal / Q000502:physiology; D018491:Dopamine Agonists / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020189:Nocturnal Myoclonus Syndrome / Q000188:drug therapy* / Q000503:physiopathology*; D010479:Pergolide / Q000627:therapeutic use*; D017286:Polysomnography; D012148:Restless Legs Syndrome / Q000188:drug therapy* / Q000503:physiopathology*; D012890:Sleep / Q000502:physiology
D018491:Dopamine Agonists; D010479:Pergolide