P355 The assessment of electrophysiological studies in patients with restless legs syndrome

Objectives To investigate the spinal excitability changes in patients with restless legs syndrome (RLS). Methods Five patients who were diagnosed as RLS clinically and free off the L-dopa treatment and 6 healthy controls (HC) were recruited. The symptom severity scale for RLS was evaluated. The electrophysiological studies consisted of F-wave studies, cutaneous silent period (CSP) recorded from extensor digitorum brevis (EDB) and abductor pollicis brevis (APB) muscles, H reflex studies recorded from soleus muscle. H reflex recruitment curves with double stimulation and H reflex during 50 Hz vibrations to Achilles tendon (Hv) were measured. Results The mean symptom severity scale was 17,4. The nerve excitability parameters, F-wave studies were not different between groups. The CSP were tended to be shorter in duration in EBD muscle in RLS patients (27 ms) than in HC (35,5 ms). The inhibition of H reflex during vibration reduced in RLS patients (Hv/Hmax%: 83,2 in RLS patients, 63,6 in HC). H reflex recruitment curves showed similar effect in inhibition and facilitation in both groups. Discussion The results of this study might reveal the increased excitability in spinal level in RLS patients. The findings in H reflex recruitment curves may be related with the small number of patients in groups. These studies displaying the spinal excitability changes would improve our understanding in pathophysiology in RLS.