Contribution of Skin Biopsy in the Diagnosis of Restless Legs Syndrome

Introduction: The diagnosis of restless legs syndrome (RLS) is an exclusively clinical diagnosis which is based on questioning the patient. Furthermore, several pathologies can mimic the symptoms of RLS. It should also be emphasized that small fiber neuropathies (SNF) escape electroneuromyography (ENMG) since this examination essentially studies large diameter myelinated fibers. The objective of this study is to assess the contribution of skin biopsy on the one hand in the differential diagnosis of RLS when an associated pathology may be responsible for NPF and on the other hand in the diagnosis of RLS with tone very painful. Patients and Methods: We carried out a prospective study covering the medical files of 2 patients followed in consultation at the Limoge University Hospital for RLS, one of whom had a systemic disease and the other had RLS evolving since then through attacks. unbearably painful. Each patient underwent a clinical evaluation based on the diagnostic criteria for RLS, an ENMG and a skin biopsy. Results: For each patient, the diagnosis of RLS was confirmed by the presence of four diagnostic criteria. Patient 1 had an IRLS score of 30/40, a normal ENMG and a normal skin biopsy with normal FNIE density. Patient 2 had RLS with a very painful tone, a normal ENMG and a skin biopsy showing rarefaction of FNIE proximally and distally, and concomitant rarefaction of subepidermal fibers. Conclusion: This study, considered preliminary with a limited sample, does not allow us to achieve the objective. A longitudinal study with a satisfactory sample could allow us to elucidate the question.