Difference in psychological distress between patients with periodic limb movement disorder and restless legs syndrome

Abstract

Background and Objective We used the Symptom Checklist 90-Revised (SCL-90-R) to compare the psychosomatic symptom profiles between periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) patients. Methods Twenty consecutive drug-naïve RLS patients, 20 age- and sex-matched patients with PLMD and healthy controls were enrolled. Questionnaires evaluating sleep (Pittsburgh Sleep Quality Index, and Insomnia Severity Index), depression (Beck Depression Inventory II), and psychosomatic symptoms (SCL-90-R) were administered. Polysomnography was performed in the patients with PLMD or RLS. Results The mean age of the subjects was 57.5 ± 10.9 years, and half of the subjects were male. Compared with the patients with RLS, the patients with PLMD exhibited a reduced total sleep time (276.6 ± 41.3 vs. 322.4 ± 42.9, p = 0.04) and a decreased proportion of REM sleep (12.5 ± 6.6 vs. 17.8 ± 7.8, p = 0.009). The patients with RLS exhibited higher SCL-90-R T-scores on the somatization (post hoc p < 0.001), obsessive-compulsive (post hoc p < 0.001), interpersonal sensitivity (post hoc p = 0.003), anxiety (post hoc p = 0.005), and psychoticism (post hoc p = 0.004) domains than the controls. Compared to the controls, the patients with PLMD exhibited higher SCL-90-R scores only in hostility (post hoc p = 0.016). Somatization in the RLS patients was significantly worse than that in the PLMD patients (post hoc p = 0.003). Conclusions The results of our study demonstrate that psychosomatic distress is greater in RLS patients and lesser in PLMD patients. Somatization was a distinguishing symptom between RLS and PLMD.