Periodic limb movement disorder and restless legs syndrome in dialysis patients

BACKGROUND: Sleep disturbances, in particular restless legs or limb movements, during the night are often reported by uremic patients. However, polysomnography (PSG) studies have never been carried out to confirm the actual occurrence of these disorders and the association with other objective and self-reported sleep-wake data. METHODS: Forty-eight participants were subjected to a 2-day PSG. These data on sleep including periodic limb movements, which are associated with restless legs, were correlated with clinical observations, quality of sleep-wake and life questionnaires, and with biochemical and neurographical measures. RESULTS: Restless legs syndrome (RLS) was observed in 58.3% of the patients and periodic limb movement disorder (PLMD) occurred in 70.8% of the patients. PLMD was revealed polysomnographically in almost 90% of the RLS patients. Patients with both PLMD and RLS had significantly poorer sleep quality than those with neither disorder or with PLMD alone, both in terms of self-reported data and the PSG. Quality of life was significantly worse in patients with RLS and PLMD compared to those patients with neither disorder. PLMD patients also tended to have a lower quality of life. All other metabolic measures and the results of a nerve conduction test were not correlated with RLS and/or PLMD. CONCLUSION: There was a high prevalence of severe RLS and PLMD in the present sample of uraemia patients. Nearly all RLS patients had severe PLMD. RLS (in combination with PLMD) in dialysis is associated with poor sleep quality, insomnia complaints, depression and emotional distress. Our results suggest that PLMD per se is also clinically relevant.