Difference in Sleep Characteristics between Restless Leg Syndrome With and Without Periodic Limb Movement during Wakefulness

Abstract

Objectives Restless leg syndrome (RLS) is a common sensorimotor disorder and is frequently associated with periodic limb movement in sleep (PLMS). Also about one third of patient with RLS have periodic limb movement during wakefulness (PLMW). However there is little research on the correlation between PLMW and RLS. We aimed to evaluate difference in sleep characteristics between patients with RLS with PLMW and those without PLMW. Methods Our study included twenty eight RLS patients. Subjects underwent suggested immobilization test (SIT) prior to one full-night polysomnography study. Patients were classified into two groups according to the presence of PLMW based on SIT-PLMW index. Polysomnographic findings, subjective sleep quality, and hematologic results were analyzed and compared between the two groups. Results Mean age of patient with frequent PLMW (SIT-PLMW ≥40/hr) was significantly higher. RLS patients with frequent PLMW were also significantly related to insomnia severity. The PLMS index was higher in patients with PLMW and showed a significant correlation with the PLMW index. Conclusions PLMW influence sleep quality such as insomnia and is correlated with movement during sleep. Keywords: Restless legs syndrome, Periodic leg movement during sleep, Periodic leg movement during wakefulness, Polysomnography, Suggested immobilization test.