Movement disorders: a sleep specialist's perspective.

Abstract

This review focuses on restless legs syndrome (RLS) and Parkinson's disease (PD). These conditions are frequently encountered in clinical sleep medicine and are among the most important of the "nonapnea" sleep disorders. RLS and PD share many features, including derangement of central dopaminergic systems as the putative cause, akathisia, and nocturnal motor fluctuations. In addition, both conditions increase in prevalence with aging, exhibit a beneficial response to dopaminergic therapy, and cause marked sleep disturbances. They frequently overlap, with about 20% of patients with PD having symptoms of RLS. Both conditions appear to have a genetic predisposition that is "turned on" by environmental factors. Adverse responses to levodopa occur in both RLS and PD, manifested as rebound and augmentation in RLS and as fluctuations in motor response and dyskinesias in PD. Newer dopaminergic agents are helpful in the management of both conditions.