Investigation into the correlation between sensation and leg movement in restless legs syndrome

We evaluated rest effects on restless legs syndrome (RLS) sensory and motor symptoms. During two 60-minute Suggested Immobilization Tests (SIT) subject's signals of RLS leg sensations and periodic leg movements while awake (PLMW) were recorded. Sensations, PLMW, sensations preceding or after PLMW, sensations occurring without following PLMW, and PLMW occurring without preceding sensation were determined. The RLS patients were divided into equal-sized high and low PLMW groups for further analysis. Data from 46 subjects (28 RLS and 18 controls) revealed sensations increased linearly with rest in RLS patients and controls. Movement rate increased linearly with rest for controls but increased rapidly for the first 45 minutes for all RLS patients. PLMW/hour increased with further rest for low but not high PLMW patients. Sensations followed by PLMW and PLMW without preceding sensations followed similar patterns. Sensations without subsequent PLMW increased dramatically in the last 15 minutes of the SITs. Whereas both sensory and motor signs of RLS increase with rest, there is minimal increase for controls. Patients with higher but not lower PLMW rates reached a ceiling for PLMW after 35 to 40 minutes. The temporal dissociation between sensory and motor events supports viewing these motor and sensory events as separate but loosely linked manifestations of RLS.