Periodic limb movements in sleep (PLMS) - Polysomnographic findings

Periodic limb movements in sleep are involuntary, stereotype and rhythmically repeated movements of the extremities (mostly of the lower ones) during sleep. They are associated with poor quality nocturnal sleep and usually cause a sensation of unrefreshing nocturnal sleep and hypersomnia in daytime. The authors present an account on 10 patients (8 men and 2 women), mean age 48.0 years, SD=11.8) with this diagnosis and on their polysomnographic findings. The most frequent subjective complaints of the patients were hypersomnia in daytime and poor quality nocturnal sleep. Two patients suffered morover from the restless leg syndrome, 4 from rhonchopathy and in two sie ep apnoe syndrome was revealed. Allnight polysomnography revealed prolonged latencies of stages 2 NREM and 3 NREM and REM sleep and prolonged wakefulness during sleep and stage 1 NREM and stage 2 NREM, while REM sleep was reduced. The mean PLMS index (number of movements per 1 hour of sleep) was 24.8 (SD=17.6). Wakening reactions were present during movements in 5 patients but poor quality sleep was recorded in all 10 patients. The authors discuss the differential diagnosis of PLMS and possible etiology of the affection. PLMS is an important cause of poor quality nocturnal sleep and its diagnosis is not possible without complete polysomnography.