Clinical characteristics of restless legs syndrome in end-stage renal failure and idiopathic RLS patients

This study was done to identify the clinical characteristics of uremic restless legs syndrome (RLS). Consecutive uremic RLS patients (n = 15) and idiopathic RLS patients (iRLS; n = 20) were evaluated. The groups were compared with respect to their clinical course, subjective symptoms [using the Pittsburgh Sleep Quality Index (PSQI) and the International Restless Legs Syndrome Severity Scale (IRLS)], polysomnographic (PSG) variables, the results of the suggested immobilization test (SIT), and the drug doses used to treat RLS. The duration of the disorder was significantly shorter in the uremic RLS group than in the iRLS group. The PSQI and IRLS scores before treatment were higher in the uremic RLS group than in the iRLS group. The periodic leg movement index (PLM index) on PSG and the SIT index were also higher in the uremic RLS group (P < 0.001, respectively). The bromocriptine equivalent dose of dopaminergic agonists used to treat RLS was significantly higher in the uremic RLS group (P < 0.001). Uremic RLS appears to deteriorate faster and to become more severe than iRLS. Moreover, uremic RLS patients appear to have a decreased response to dopaminergic agonists. (C) 2007 Movement Disorder Society.