title: Central and peripheral nervous system excitability in restless legs syndrome.
abstract: Neurophysiological techniques have been applied in restless legs syndrome (RLS) to obtain direct and indirect measures of central and peripheral nervous system excitability, as well as to probe different neurotransmission pathways. Data converge on the hypothesis that, from a pure electrophysiological perspective, RLS should be regarded as a complex sensorimotor disorder in which cortical, subcortical, spinal cord, and peripheral nerve generators are all involved in a network disorder, resulting in an enhanced excitability and/or decreased inhibition. Although the spinal component may have dominated in neurophysiological assessment, possibly because of better accessibility compared to the brainstem or cerebral components of a hypothetical dysfunction of the diencephalic A11 area, multiple mechanisms, such as reduced central inhibition and abnormal peripheral nerve function, contribute to the pathogenesis of RLS similarly to some chronic pain conditions. Dopamine transmission dysfunction, either primary or triggered by low iron and ferritin concentrations, may also bridge the gap between RLS and chronic pain entities. Further support of disturbed central and peripheral excitability in RLS is provided by the effectiveness of nonpharmacological tools, such as repetitive transcranial magnetic stimulation and transcutaneous spinal direct current stimulation, in transiently modulating neural excitability, thereby extending the therapeutic repertoire. Understanding the complex interaction of central and peripheral neuronal circuits in generating the symptoms of RLS is mandatory for a better refinement of its therapeutic support.
authors.affiliation: Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy. Electronic address: glanza@oasi.en.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lanza
authors.affiliation: Department of Neurology, Paracelsus Klinik, Osnabrueck, Germany.
authors.forename: Cornelius G
authors.initials: CG
authors.lastname: Bachmann
authors.affiliation: Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France; CNRS, INCIA, CNRS UMR 5287, Université de Bordeaux, Bordeaux, France.
authors.forename: Imad
authors.initials: I
authors.lastname: Ghorayeb
authors.affiliation: Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy.
authors.forename: Raffale
authors.initials: R
authors.lastname: Ferri
authors.affiliation: Department of Clinical Neurophysiology, University Medical Center, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Paulus
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000503:physiopathology*; D006801:Humans; D017933:Peripheral Nervous System / Q000503:physiopathology*; D012148:Restless Legs Syndrome / Q000503:physiopathology*
keywords: Cortical plasticity; Cortical–spinal network; Dopaminergic pathways; Iron metabolism; Neuronal excitability; Restless legs syndrome