Excessive Daytime sleepiness in idiopathic restless legs syndrome: characteristics and evolution under dopaminergic treatment.

Objective: Whereas insomnia is frequent in restless legs syndrome (RLS), little is known about daytime sleepiness. We studied a series of 27 consecutive patients with idiopathic RLS in order to identify the characteristics and evolution of excessive daytime sleepiness (EDS) under dopaminergic treatment.

Methods: Patients were assessed by clinical examination, questionnaires and video-polysomnography (PSG). Sleepy patients, as defined by Epworth Sleepiness Scale (ESS) >10, were also assessed by the multiple sleep latency test (MSLT). We excluded RLS patients with other sleep-wake disorders, in particular chronic sleep deprivation.

Results: Mean age was 56 years, the mean International RLS Study Group Rating Scale score was 24 at baseline. Ten (37%) of the 27 patients reported EDS. RLS patients with sleepiness had a higher amount of total sleep time (p = 0.029) on PSG and a mean sleep latency of 6.4 min on MSLT. No other differences regarding clinical or polysomnographic parameters were found. RLS severity improved in all patients under dopaminergic treatment (p = 0.001); this was also the case for the ESS score in sleepy patients (p = 0.007).

Conclusions: In our series of RLS patients, EDS was common, characterized by longer sleep (PSG) and reduced sleep latencies on MSLT. Under dopaminergic treatment, both RLS severity and ESS improved.