Tongue Position Variability During Sustained Notes in Healthy vs Dystonic Horn Players Using Real-Time MRI

OBJECTIVE: Embouchure dystonia (EmD) is a variant of focal task-specific dystonia in musicians characterized by the loss of control in facial and oral muscles while controlling airflow into the mouthpiece of a wind or brass instrument. We compared tongue position variability (TPV) during sustained notes between healthy, elite horn players and horn players affected by EmD. METHODS: Real-time MRI films at 33.3 ms resolution were obtained from 8 healthy elite and 5 EmD horn players as they performed on a non-ferromagnetic horn at each of three different dynamic levels: pianissimo, mezzo forte, and fortissimo. Nine profile lines (3 from anterior, 3 from middle, and 3 from posterior oral cavity regions) were overlaid on each image using a customized MATLAB toolkit, and the variability of the dorsal tongue edge position was examined at each dynamic from temporal intensity profiles produced by MATLAB. RESULTS: Despite trends for more pronounced TPV (larger standard deviations) in the elite musicians (p=0.062), 2-way repeated measures ANOVA revealed no significant differences between groups. However, dynamic level significantly influenced TPV for all subjects, combined (p=0.048) and different regions of the oral cavity showed differing TPV (p EmD, p