title: Altered pattern of motor cortical activation-inhibition during voluntary movements in Tourette syndrome.
abstract: In patients with Gilles de la Tourette syndrome (GTS) alterations of motor cortex (M1) excitability at rest have been evidenced. In contrast, there has so far been little research into changes of motor cortical reactivity during the time course of voluntary movements in GTS patients. The present study investigates neuromagnetic event-related desynchronization (ERD) and event-related synchronization (ERS) of bilateral M1 in 11 GTS patients and 11 healthy control subjects. ERD represents motor cortical activation, whereas ERS most likely indicates its inhibition. Subjects performed a self-paced finger movement task while magnetoencephalography was used to record neuromagnetic activity. In GTS patients, ERD at beta frequency was significantly increased in the contralateral hemisphere before and during movements, whereas ERS following movement termination was increased in M1 ipsilateral. Ipsilateral ERS was inversely correlated with tic severity as determined by the Yale Global Tic Severity Rating Scale. The data of the present study support the hypothesis that during voluntary movements, motor cortical reactivity is pathologically altered in GTS patients. The observed pattern of increased activation (ERD) prior to and during movement execution followed by increased inhibition (ERS) after movement termination at beta frequency suggests abnormally increased motor cortical activation, possibly driving stronger inhibition. The stronger this inhibition is, the better symptoms appear to be controlled.
authors.affiliation: Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine University, Duesseldorf, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Franzkowiak
authors.forename: Bettina
authors.initials: B
authors.lastname: Pollok
authors.forename: Katja
authors.initials: K
authors.lastname: Biermann-Ruben
authors.forename: Martin
authors.initials: M
authors.lastname: Südmeyer
authors.forename: Jennifer
authors.initials: J
authors.lastname: Paszek
authors.forename: Melanie
authors.initials: M
authors.lastname: Jonas
authors.forename: Götz
authors.initials: G
authors.lastname: Thomalla
authors.forename: Tobias
authors.initials: T
authors.lastname: Bäumer
authors.forename: Michael
authors.initials: M
authors.lastname: Orth
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
authors.forename: Alfons
authors.initials: A
authors.lastname: Schnitzler
mesh_terms: D000328:Adult; D003344:Cortical Synchronization / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005385:Fingers; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D005879:Tourette Syndrome / Q000503:physiopathology*