Structure-function abnormalities in cortical sensory projections in embouchure dystonia

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Embouchure dystonia (ED) is a task-specific focal dystonia affecting professional brass musicians.
• Previous research identified abnormal sensorimotor function and structure in ED patients.
• Underlying white matter tract abnormalities in ED remain largely unknown.

Purpose of the Study:

• To investigate structure-function abnormalities in cerebral sensorimotor pathways in ED patients.
• To delineate white matter tract integrity and functional connectivity within the sensorimotor network.

Main Methods:

• Employed probabilistic tractography and seed-based functional connectivity analysis.
• Examined a sensorimotor network including supplementary motor, superior parietal, primary somatosensory/motor cortex, and putamen.
• Performed post-hoc grey matter volumetry on affected cortical regions.

Main Results:

• ED patients exhibited reduced axial diffusivity in primary somatosensory cortex-putamen projections.
• Increased axial diffusivity and anisotropy were observed in supplementary motor and superior parietal cortex projections.
• Reduced functional connectivity between the left primary somatosensory cortex and putamen correlated with diffusivity changes; increased grey matter volume in the left primary somatosensory cortex.

Conclusions:

• Abnormal tract integrity in sensorimotor pathways supports dysfunctional sensory processing in ED.
• Differential abnormalities in cortico-cortical and cortico-subcortical tracts suggest complex, non-uniform sensory system alterations in ED.