Elisabeth Ruppert1, Marc Bataillard2, Izzie Jacques Namer3, Laurent Tatu4, Aurélien Hacquard5, Laurence Hugueny2, Jeffrey Hubbard2, Ulker Kilic-Huck2, Valérie Wolff6, Patrice Bourgin2. 1. Department of Neurology, Sleep Disorders Center - CIRCSom, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; CNRS UPR 3212, Institute for Cellular and Integrative Neurosciences, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, Strasbourg, France. Electronic address: elisabeth.ruppert@chru-strasbourg.fr. 2. Department of Neurology, Sleep Disorders Center - CIRCSom, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; CNRS UPR 3212, Institute for Cellular and Integrative Neurosciences, Strasbourg, France; Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, Strasbourg, France. 3. Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, Strasbourg, France; Department of Biophysics and Nuclear Medicine, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; ICube, CNRS, UMR 7237, University of Strasbourg, Strasbourg, France. 4. Department of Anatomy, UFR Sciences Médicales et Pharmaceutiques, University of Franche-Comté, Besançon, France; Department of Neuromuscular Diseases, CHU Besançon, Besançon, France. 5. Department of Neurology, Sleep Disorders Center - CIRCSom, Hôpitaux Universitaires de Strasbourg, Strasbourg, France. 6. Fédération de Médecine Translationnelle de Strasbourg (FMTS), University of Strasbourg, Strasbourg, France; ICube, CNRS, UMR 7237, University of Strasbourg, Strasbourg, France; Department of Neurology, Stroke Unit, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Abstract
OBJECTIVE: The pathophysiology of restless legs syndrome (RLS) involves a dopaminergic dysregulation that remains poorly understood, with controversial data from the literature. Stroke-related RLS is a rare condition that involves primarily the basal ganglia, the paramedian pons, and the thalamus. Given these elements, we studied dopaminergic metabolism in patients with RLS secondary to lenticulostriate infarction using structural and nuclear imaging in the striatum ipsilateral to the infarction area, as compared to the contralateral side. We hypothesized that dopaminergic metabolism would be impaired in the striatum ipsilateral to stroke. METHODS: In this observational case-control study, we aimed to prospectively include patients with RLS secondary to lenticulo-striate infarction, for analyses of dopamine dysfunction ipsilateral to stroke as compared to the contralateral striatum and to a control population. Four patients fulfilled inclusion criteria with either de novo RLS or major exacerbation of RLS existing prior to stroke, and all four patients were included. Structural imaging was performed using brain magnetic resonance imaging, and the stroke-induced metabolic modifications were assessed by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). Dopamine reuptake via DAT was explored using 123I-FP-CIT SPECT. PET with 18F-FDOPA was used to evaluate the functional integrity of the presynaptic dopaminergic synthesis. RESULTS: The only structure damaged in all patients was the body of the caudate nucleus, right-sided for three and left-sided for one, as illustrated by magnetic resonance imaging. 18F-FDG PET showed a hypometabolism in the infarcted area, the ipsilateral thalamus, and the contralateral cerebellum. All patients displayed, in the ipsilateral putamen, increased dopaminergic tone. CONCLUSION: The present findings suggest that increased dopaminergic tone in the striatum may participate in the pathogenesis of RLS. These observations should encourage further research on RLS symptomatic with well-defined lesions as a promising way to further improve our understanding of its pathophysiology.
OBJECTIVE: The pathophysiology of restless legs syndrome (RLS) involves a dopaminergic dysregulation that remains poorly understood, with controversial data from the literature. Stroke-related RLS is a rare condition that involves primarily the basal ganglia, the paramedian pons, and the thalamus. Given these elements, we studied dopaminergic metabolism in patients with RLS secondary to lenticulostriate infarction using structural and nuclear imaging in the striatum ipsilateral to the infarction area, as compared to the contralateral side. We hypothesized that dopaminergic metabolism would be impaired in the striatum ipsilateral to stroke. METHODS: In this observational case-control study, we aimed to prospectively include patients with RLS secondary to lenticulo-striate infarction, for analyses of dopaminedysfunction ipsilateral to stroke as compared to the contralateral striatum and to a control population. Four patients fulfilled inclusion criteria with either de novo RLS or major exacerbation of RLS existing prior to stroke, and all four patients were included. Structural imaging was performed using brain magnetic resonance imaging, and the stroke-induced metabolic modifications were assessed by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). Dopamine reuptake via DAT was explored using 123I-FP-CIT SPECT. PET with 18F-FDOPA was used to evaluate the functional integrity of the presynaptic dopaminergic synthesis. RESULTS: The only structure damaged in all patients was the body of the caudate nucleus, right-sided for three and left-sided for one, as illustrated by magnetic resonance imaging. 18F-FDG PET showed a hypometabolism in the infarcted area, the ipsilateral thalamus, and the contralateral cerebellum. All patients displayed, in the ipsilateral putamen, increased dopaminergic tone. CONCLUSION: The present findings suggest that increased dopaminergic tone in the striatum may participate in the pathogenesis of RLS. These observations should encourage further research on RLS symptomatic with well-defined lesions as a promising way to further improve our understanding of its pathophysiology.
Authors: Malik Hamdaoui; Elisabeth Ruppert; Henri Comtet; Ulker Kilic-Huck; Valérie Wolff; Marc Bataillard; Patrice Bourgin Journal: J Spinal Cord Med Date: 2017-09-12 Impact factor: 1.985