Normal Temporal Discrimination in Musician's Dystonia Is Linked to Aberrant Sensorimotor Processing

Area of Science:

• Neuroscience
• Clinical Neurology
• Sensory Perception

Background:

• Sensory discrimination alterations are key nonmotor features of dystonia.
• Abnormal temporal discrimination is a potential endophenotype for focal dystonia, but its neural basis is unclear.

Purpose of the Study:

• To investigate the relationship between visual temporal discrimination threshold (TDT) and brain activity in musician's dystonia, nonmusician's dystonia, and healthy controls.

Main Methods:

• Compared TDT z scores between 42 dystonia patients (musician and nonmusician) and 41 healthy controls.
• Examined associations between TDT z scores, clinical dystonia features, and resting-state functional brain activity using nonparametric correlations.

Main Results:

• Healthy controls differed from nonmusician dystonia patients in TDT z scores, but not musician dystonia patients.
• A relationship between normal TDT and inferior parietal cortex activity in controls was absent in all patients.
• Musician dystonia showed additional TDT correlations with premotor, somatosensory, and visual cortices, precuneus, and cerebellum; nonmusician dystonia showed a trend in the lingual gyrus and cerebellum.

Conclusions:

• TDT may be an endophenotypic marker primarily for nonmusician dystonia.
• Compensatory neural adaptations likely normalize TDT in musician dystonia but not nonmusician dystonia.