Introduction: Recent clinical and functional imaging data suggest impaired central dopaminergic transmission in restless legs syndrome (RLS). As RLS responds to dopaminergic medications, an etiologic link between RLS and Parkinson's disease (PD) has been proposed. However, few studies have examined this association.
Objective: To investigate the prevalence of RLS amongst PD outpatient population.
Method: The prevalence of RLS was determined by the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG). Consecutive PD patients (n=125) were prospectively evaluated in our clinic.
Results: There were 77 (61.6%) males and 48 (38.4%) females with a mean age of 65.1+/-9.3 (SD) years (range 34-83), and mean age of onset of disease at 59.6 years+/-10.7 (SD) years (range 30-81). Nineteen (15.2%) patients had motor restlessness. Of these, one (0.8%) patient had RLS-like symptoms closely correlated to wearing "off" effect of levodopa. None of the patients satisfied the IRLSSG diagnostic criteria of RLS. This was not significantly different compared to the 0.6% and 0.1% RLS prevalence in our general population and clinic population.
Conclusions: Our study demonstrates that motor restlessness was present in 15.2% of our PD patients. However, prevalence of RLS in our PD patients was not significantly different from our general population or clinic population, suggesting that these two diseases may not share the same pathophysiologic mechanism.