Commentary

RLS is common (2–5% of the population) and distressing, especially when it occurs at night. The mean age of onset is 25–30 years. It is a lifelong condition and is becoming increasingly common in elderly people. At least one third of cases are hereditary and are often autosomal dominant. 80% of people with RLS have PLMs in sleep (5% of people 30–50 y and 29% of people 50–60 y) in the general population.¹ Up to 19% of women experience RLS during pregnancy, but it is usually temporary.¹

RLS must be distinguished from akathisia, myoclonus, pain from lumbosacral spinal stenosis, or “painful feet and moving toes.” The pathophysiology of RLS is unclear. RLS may accompany iron or vitamin deficiency, uremia, occlusive arterial disease, congestive cardiac failure, peripheral neuropathy, and other neurological diseases and may respond to treatment of the primary disorder. Diagnosis of RLS can usually be made clinically, and sleep studies are not essential. Sleep studies, however, provide useful objective outcome measures for research² and treatment trials, which are plagued by prominent placebo responses.¹

The best validated treatment option is the use of dopaminergic drugs. Bedtime levodopa provides rapid improvement,¹ but rebound symptoms may occur later at night. Benzodiazepines, especially clonazepam, may improve sleep quality, and opioids reduce sleep arousals.¹. Both drug classes, however, have risk for dependence. Randomised controlled trials of carbamazepine treatment have shown promise, and clonidine, bromocriptine, and baclofen may also be helpful.¹

This well-done study by Wetter and colleagues supports the results of open studies³ reporting that pergolide is effective in the short term and is thus a reasonable treatment option. It should now be tested against other available treatments for comparative efficacy. Until such comparisons are made, levodopa and clonazepam are less expensive treatments that can work well and should probably be tried first.