title: Defective inhibition and inter-regional phase synchronization in pianists with musician's dystonia: an EEG study.
abstract: Recent neurophysiological studies have associated focal-task specific dystonia (FTSD) with impaired inhibitory function. However, it remains unknown whether FTSD also affects the inhibition (INH) of long-term overlearned motor programs. Consequently, we investigated in a Go/NoGo paradigm the neural correlates associated with the activation (ACT) and inhibition of long-term overlearned motor memory traces in pianists with musician's dystonia (MD), a form of FTSD, during a relevant motor task under constraint timing conditions with multichannel EEG. In NoGo trials, the movement related cortical potentials showed a positive shift after the NoGo signal related to inhibition and was significantly smaller over sensorimotor areas in musicians with MD. Further, we observed an increase at 850-900 ms in the power of beta oscillations which was significantly weaker for the patient group. The role of the inter-electrode phase coupling in the sensorimotor integration of inhibitory processes turned out to be the most relevant physiological marker: the global phase synchronization during INH exhibited an increase between 230 and 330 ms and 7-8 Hz, increase which was significantly smaller for pianists with MD. This effect was due to a weaker phase synchronization between the supplementary motor cortex and left premotor and sensorimotor electrodes in patients. Thus, our findings support the hypothesis of a deficient phase coupling between the neuronal assemblies required to inhibit motor memory traces in patients with MD. EMG recorded from the right flexor pollicis longus muscle confirmed that patients with MD had a disrupted INH in NoGo trials.
authors.affiliation: Institute of Music Physiology and Musician's Medicine, Hanover University of Music and Drama, Hanover 30161, Germany.
authors.forename: María Herrojo
authors.initials: MH
authors.lastname: Ruiz
authors.forename: Patricia
authors.initials: P
authors.lastname: Senghaas
authors.forename: Michael
authors.initials: M
authors.lastname: Grossbach
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Jabusch
authors.forename: Marc
authors.initials: M
authors.lastname: Bangert
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Hummel
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.forename: Eckart
authors.initials: E
authors.lastname: Altenmüller
mesh_terms: D000108:Acetylcarnitine; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D016000:Cluster Analysis; D003344:Cortical Synchronization; D004421:Dystonia / Q000503:physiopathology*; D004569:Electroencephalography; D004576:Electromyography; D019054:Evoked Potentials, Motor; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D009146:Music; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D013647:Task Performance and Analysis; D013997:Time Factors
chemical_list: D000108:Acetylcarnitine