Anna Latorre1,2, Lorenzo Rocchi1, Alfredo Berardelli2,3, Kailash P Bhatia1, John C Rothwell1. 1. Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology University College London, London, United Kingdom. 2. Department of Neurology and Psychiatry, Sapienza, University of Rome, Rome, Italy. 3. Istituto di Ricovero e Cura a Carattere Scientifico Neuromed, Pozzilli, Isernia, Italy.
Abstract
BACKGROUND: A large number of methods have been described that use transcranial magnetic stimulation to probe the physiology of the human motor cortex. Since the 1990s, hundreds of papers have used them to investigate neurophysiological signatures of different types of movement disorders. However, in recent years there has been increasing recognition of the interindividual variability of these measures and a focus on estimating their reliability and reproducibility. Although this work has been carried out in healthy individuals, it is highly relevant to movement disorders because it may impact the validity of some accepted ("canonical") neurophysiological biomarkers. The aim of this review is to reexamine the diagnostic usefulness of transcranial magnetic stimulation methods in movement disorders in the context of present knowledge of methodological variability. METHODS: We conducted a search of the PubMed database for research and review articles on transcranial magnetic stimulation and its diagnostic utility in movement disorders (specifically Parkinson's disease and atypical parkinsonism, dystonia, Tourette syndrome and other chronic tic disorders, Huntington's disease, and essential tremor). We highlighted contradictions in the literature and common misconceptions with the aim of providing a clearer picture of the reliability of these measures in differential diagnosis of movement disorders. CONCLUSION: Although there is no doubt that these studies have provided useful insight into the pathophysiology of movement disorders, there is a clear disagreement among many studies that questions the validity of some of the so called "canonical" findings as diagnostic markers. However, useful findings remain and even those with higher variability can be used to support clinical diagnosis in selected cases.
BACKGROUND: A large number of methods have been described that use transcranial magnetic stimulation to probe the physiology of the human motor cortex. Since the 1990s, hundreds of papers have used them to investigate neurophysiological signatures of different types of movement disorders. However, in recent years there has been increasing recognition of the interindividual variability of these measures and a focus on estimating their reliability and reproducibility. Although this work has been carried out in healthy individuals, it is highly relevant to movement disorders because it may impact the validity of some accepted ("canonical") neurophysiological biomarkers. The aim of this review is to reexamine the diagnostic usefulness of transcranial magnetic stimulation methods in movement disorders in the context of present knowledge of methodological variability. METHODS: We conducted a search of the PubMed database for research and review articles on transcranial magnetic stimulation and its diagnostic utility in movement disorders (specifically Parkinson's disease and atypical parkinsonism, dystonia, Tourette syndrome and other chronic tic disorders, Huntington's disease, and essential tremor). We highlighted contradictions in the literature and common misconceptions with the aim of providing a clearer picture of the reliability of these measures in differential diagnosis of movement disorders. CONCLUSION: Although there is no doubt that these studies have provided useful insight into the pathophysiology of movement disorders, there is a clear disagreement among many studies that questions the validity of some of the so called "canonical" findings as diagnostic markers. However, useful findings remain and even those with higher variability can be used to support clinical diagnosis in selected cases.
Authors: Willem B Verwey; Benedikt Glinski; Min-Fang Kuo; Mohammad Ali Salehinejad; Michael A Nitsche Journal: Exp Brain Res Date: 2022-04-07 Impact factor: 1.972