Restless legs syndrome and periodic limb movements of sleep

Patients afflicted with restless legs syndrome (RLS) experience an urge to move the limbs that most often is accompanied by unpleasant limb sensations. These symptoms are most severe at rest and improve with movement of the affected limb. In contrast to these limb movements voluntarily executed to attenuate RLS symptoms, periodic limb movements (PLM) are repetitive, highly stereotyped, involuntary movements that can occur during sleep (PLMS) or wakefulness (PLMW). Although these disorders may occur in isolation, they often are comorbid. Both RLS and PLM frequently occur in patients with Parkinson’s disease (PD), although it remains controversial whether the prevalence of these conditions is greater in PD patients than in the general population. RLS, PLM, and PD may all respond to dopaminergic medications; the degree to which the pathophysiology of these conditions overlaps is still being explored. As RLS and PLMS may be a cause of poor sleep and excessive daytime sleepiness in the PD population, effective treatment for these conditions can significantly improve the quality of life.