Soleus MEP-80 response latency in restless legs syndrome

Abstract

Introduction The purpose of this study was to investigate the latency of soleus MEP-80 response in patients with restless legs syndrome (RLS). We aimed to figure out the etiopathogenesis and to determine an objective diagnostic tool and prognosis indicator. Materials and methods In this study, 40 patients with RLS and 40 controls were included. For all patients and controls routine laboratory investigations, electroneurography (ENG) and transcranial cortical magnetic stimulation (TCCMS) were performed. Finally the MEP-80 response latency of 40 RLS patients and 40 age and gender matched controls were compared. All patients were diagnosed with the 4 criteria defined by ICSD 2 and the severity was classified according to the international restless legs syndrome scaling group (IRLSSG) classification. Results The soleus MEP-80 response latency in RLS patients and controls was 96 ms (SD: ± 12.5) and 81.8 ms (SD: ± 3.4), respectively. The difference between both groups was statistically significant (p ± 8.3 ms n = 24) than in mild-moderate RLS patients (83.2 ms; SD: ± 3.4; n = 16). Conclusion In restless legs syndrome it is known that the corticospinal tract is not directly affected but subcortical inhibition is influenced due to functional spinal neuron impairment. As a result of this study we determined a direct functional impairment of spinal afferent and efferent long reflexes and we recognized that corticospinal late responses are affected in RLS. According to the results of our study we think that Soleus MEP 80 responce can be a new diagnostic modality and a prognostic indicator for RLS patients. Acknowledgements Department of Neurophysiology, Dokuz Eylul University Medical School.