Characterizing the temporal discrimination threshold in musician’s dystonia

Abstract

The temporal discrimination threshold (TDT) has been established as a biomarker of impaired temporal processing and endophenotype in various forms of focal dystonia patients, such as cervical dystonia, writer’s cramp or blepharospasm. The role of TDT in musician’s dystonia (MD) in contrast is less clear with preceding studies reporting inconclusive results. We therefore compared TDT between MD patients, healthy musicians and non-musician controls using a previously described visual, tactile, and visual-tactile paradigm. Additionally, we compared TDT of the dystonic and non-dystonic hand and fingers in MD patients and further characterized the biomarker regarding its potential influencing factors, i.e. musical activity, disease variables, and personality profiles. Repeated measures ANOVA and additional Bayesian analyses revealed lower TDT in healthy musicians compared to non-musicians. However, TDTs in MD patients did not differ from both healthy musicians and non-musicians, although pairwise Bayesian t-tests indicated weak evidence for group differences in both comparisons. Analyses of dystonic and non-dystonic hands and fingers revealed no differences. While in healthy musicians, age of first instrumental practice negatively correlated with visual-tactile TDTs, TDTs in MD patients did not correlate with measures of musical activity, disease variables or personality profiles. In conclusion, TDTs in MD patients cannot reliably be distinguished from healthy musicians and non-musicians and are neither influenced by dystonic manifestation, musical activity, disease variables nor personality profiles. Unlike other isolated focal dystonias, TDT seems not to be a reliable biomarker in MD.

Video-based diagnosis support system for pianists with Musician’s dystonia

“…Although Musician’s dystonia is a disorder in which dexterity is impaired primarily during the performance of specific tasks, it is known that there are differences in hand perceptive or sensory-motor functions unrelated to specific motor tasks, such as longer temporal discrimination threshold (TDT), compared to healthy individuals ( 18 , 19 ). Conversely, it has been reported that TDT is not altered in musicians with dystonia ( 20 ). Furthermore, biomechanical factors seem to be related to musicians with dystonia, at least in a subgroup ( 11 , 21 ).…”

“…TOJT of the participants was defined as the time interval at which the correction rate exceeded 75% ( Supplementary Figure 1-3 ). We opted for mechanical stimulation instead of electrical stimulation for simplicity, while adhering to the target body parts of previous studies that measure TDT of patients with MD ( 20 ). Prior to measurements, we ensured that the magnitude of the mechanical stimuli was sufficiently above each participant’s tactile threshold.…”