Intact Organization of Tactile Space Perception in Isolated Focal Dystonia.

Tina Mainka,Kirsten E Zeuner,Elena Azañón,Friederike Borngräber,Andrea A Kühn,Matthew R Longo,Wolf‐Julian Neumann,Arne Knutzen,Christos Ganos,Tobias Bäumer

doi:10.1002/mds.28607

Abstract

Systematic perceptual distortions of tactile space have been documented in healthy adults. In isolated focal dystonia impaired spatial somatosensory processing is suggested to be a central pathophysiological finding, but the structure of tactile space for different body parts has not been previously explored. The objective of this study was to assess tactile space organization with a novel behavioral paradigm of tactile distance perception in patients with isolated focal dystonia and controls. Three groups of isolated focal dystonia patients (cervical dystonia, blepharospasm/Meige syndrome, focal hand dystonia) and controls estimated perceived distances between 2 touches across 8 orientations on the back of both hands and the forehead. Stimulus size judgments differed significantly across orientations in all groups replicating distortions of tactile space known for healthy individuals. There were no differences between groups in the behavioral parameters we assessed on the hands and forehead. Tactile space organization is comparable between patients with isolated focal dystonia and healthy controls in dystonic and unaffected body parts. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Highlights

Focal hand dystonia (FHD) is an idiopathic, adult-onset disorder in most cases and manifests only while performing specific tasks.[1]
We explored tactile space organization across Isolated focal dystonias (IFDs) patients using a novel behavioral paradigm, which allows quantification of distortions in tactile spatial perception and matches cortical tactile space organization in the primary somatosensory cortex.[7,12]
Stimulus size judgments differed across orientations in controls and in groups of patients with CD, BSP/Meige syndrome, and FHD, replicating distortions of tactile space previously shown for healthy individuals.[7]

Summary

Introduction

Focal hand dystonia (FHD) is an idiopathic, adult-onset disorder in most cases and manifests only while performing specific tasks.[1] Writer’s cramp and musician’s dystonia are the most well-known types of FHD, both of which cause dystonic muscle contractions in hand muscles only while writing or playing musical instruments. The prevalence of this condition is 1.2–1.5 per 100,000 persons.[2,3,4] In some specific populations, such as professional musicians or athletes, the prevalence is much higher than in the general population; approximately 1%–2% of professional musicians are affected by FHD.[5,6]. Its efficacy for the treatment of FHD has been investigated in only two patients far.[11,12] we prospectively

Methods

Results

Conclusion