Abnormal interhemispheric inhibition in musician's dystonia – Trait or state?

Abstract

Introduction: A clustering of relatives with dystonia has been reported in families with musician’s dystonia suggesting a genetic contribution to this disease. The aim of the present study was to determine whether interhemispheric inhibition (IHI) measured with transcranial magnetic stimulation is impaired in healthy family members rendering it a suitable endophenotypic marker for musician’s dystonia. Methods: Patients with musician’s hand dystonia (n ¼ 21), patients with sporadic writer’s cramp (n ¼ 15), their healthy family members (n ¼ 27), healthy musicians (n 12) and healthy non-musicians (n = 12) were included. An extended interview about the family history and musical activity was performed. IHI in both hemispheres was measured using transcranial magnetic stimulation. Results: A stepwise regression analysis revealed musical activity (p ¼ 0.001) and a family history of Endophenotype dystonia (p ¼ 0.008) but not dystonia per se, age, handedness or gender as relevant factors modulating IHI. Conclusion: These data support the notion of a genetic background of musician’s hand dystonia and suggests that reduced IHI is a possible endophenotypic marker of this disorder.

Aberrant cortical excitability reflects the loss of hand dexterity in musician's dystonia

“…An EEG study also reported absence of oscillatory activities associated with action inhibition in patients with hand FTSD (Hummel et al 2002). The reduced motor cortical inhibition in musicians' dystonia can also be related to genetic predisposition (Baumer et al 2016). A novel finding of the present study is that the reduced SICI was related to increased variability of the timing control of sequential finger movements in pianists with MD.…”

“…The reduced motor cortical inhibition in musicians’ dystonia can also be related to genetic predisposition (Baumer et al . ). A novel finding of the present study is that the reduced SICI was related to increased variability of the timing control of sequential finger movements in pianists with MD.…”

Functional abnormalities in the cerebello-thalamic pathways in a mouse model of DYT25 dystonia

“…The tactile temporal discrimination threshold (TDT) is increased in different types of isolated dystonia, nonmanifesting DYT1-mutation carriers, and unaffected relatives of both familial and sporadic adult-onset dystonia patients, and the somatotopic representation of fingers in the S1 cortex was disorganized on both sides in unilaterally affected dystonic patients ( Meunier et al, 2001 ). Inter-hemispheric inhibition, as assessed by dual-site paired-pulse TMS, is reduced in asymptomatic individuals but with a family history of dystonia ( Bäumer et al, 2016 ). A critical issue is that these subclinical physiological alterations may not be specific to dystonia: for example, TDT was found abnormal in Parkinson’s disease ( Conte et al, 2016 ) and psychogenic dystonia ( Morgante et al, 2011 ).…”

Focal task specific dystonia: a review and update

“…Additionally, in a study of musicians with FTSD of the hand, along with patients with writer’s cramp and their relatives, reduced interhemispheric inhibition as measured by transcranial magnetic stimulation (TMS) was observed in individuals where there was a positive family history for dystonia. This finding suggests that reduced interhemispheric inhibition may serve as a possible endophenotypic marker of genetic susceptibility for developing FTSD [ 23 ].…”