Restless leg syndrome is a treatable cause of sleep disturbance and fatigue in primary biliary cirrhosis.

Background: Primary biliary cirrhosis (PBC) patients frequently describe sleep problems. The cause remains unclear and treatment is challenging. Restless leg syndrome (RLS) is a common sleep disorder. In this study, we systematically screened PBC patients for the presence of RLS.

Methods: Participants were recruited from our specialist PBC clinical service. Subjects completed the International Restless Leg Syndrome Study Group rating scale (IRLSS) a validated measure of the presence of RLS and its severity. Those fulfilling diagnostic criteria for RLS underwent foot actigraphy (CamNtech Actiwatch) to objectively assess periodic limb movement index (PLMI) (normal <5/h).

Results: Restless leg syndrome was assessed in 42 consecutive early stage PBC patients. Twelve (29%) fulfilled the IRLSS criteria for RLS. Scores were significantly higher in PBC compared to controls (P = 0.005). Twenty-four patients were further assessed with foot actigraphy for 3 nights (12 with subjective RLS symptoms and 12 with no RLS symptoms). Thirteen of twenty-four subjects had PLMI >5/h and four had moderate or severe PLMI >15/h. All moderate or severe PLMI subjects had subjective symptoms of moderate or severe RLS. No patients had PLMI >10 in the absence of RLS symptoms. Eleven PBC patients with symptomatic RLS went on to have treatment. Sixty-three per cent had clear benefit in restless leg symptoms and associated symptoms of fatigue.

Conclusion: Restless leg syndrome symptoms are common and underdiagnosed in PBC patients. RLS represents a potential therapy for PBC patients with daytime sleepiness, fatigue and unpleasant lower limb symptoms and this is worthy of further studies in larger cohorts.