Microstructural white matter changes underlying speech deficits in Parkinson's disease.

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Speech impairments are a common symptom in Parkinson's disease (PD).
• The specific neuroanatomical structural deficits within the basal ganglia-thalamocortical (BGTC) loop underlying these speech deficits in PD remain largely unknown.
• Understanding these deficits is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate white matter differences in the BGTC loop in individuals with Parkinson's disease (PD) and their association with speech deficits.
• To identify distinct neuroanatomical markers for speech impairment in PD.

Main Methods:

• Utilized diffusion tensor imaging (DTI) data from the Parkinson's Progression Markers Initiative (PPMI) database.
• Employed probabilistic tractography to analyze white matter integrity within the BGTC pathway.
• Compared three groups: PD with speech deficits, PD without speech deficits, and age/gender-matched controls.

Main Results:

• Individuals with PD and speech deficits exhibited significantly higher mean diffusivity in the left hemisphere's BGTC pathway compared to PD individuals without speech deficits.
• This finding indicates altered white matter microstructure in the BGTC loop is associated with speech impairment in PD.

Conclusions:

• The study suggests a distinct white matter pathophysiological profile associated with speech deficits in Parkinson's disease.
• These findings highlight the role of BGTC white matter integrity in PD-related speech impairments and may inform future diagnostic and therapeutic strategies.