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

Abstract

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. 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). 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. 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.