Restless legs syndrome in sensory axonal neuropathy: A case-control study

The relation between neuropathy and restless legs syndrome (RLS) remains uncertain. Previous studies have analyzed heterogeneous neuropathic populations and findings have been to date inconsistent.

We studied a neuropathic population consisting of 59 patients with acquired, mixed, small and large fiber sensory axonal neuropathy. We compared our findings to those of 59 neurological controls with a similar age/gender distribution. International RLS Study Group criteria were used and severity assessed by International Restless Legs Syndrome Severity Scores (IRLSSS), by a single blinded telephone interviewer. Mimics were excluded as well as cases with infrequent (<5 days/month) symptoms.

RLS was significantly more frequent in patients with neuropathy than in controls (28.8% versus 8.5%; P=0.008). Patients with neuropathy and RLS were significantly older (P=0.001), had later onset RLS (P=0.001), had more frequent RLS symptoms (P=0.009) and greater IRLSSS (P=0.019), than controls with RLS. There was no relation between presence of RLS in patients with sensory neuropathy and lower limb sensory electrophysiological findings.

Our results suggest that acquired sensory axonal neuropathy may be associated with RLS. Further larger studies of homogeneous neuropathic populations are required in view of the potential therapeutic benefit specifically for RLS symptoms in patients with neuropathy.