White matter microstructures in Parkinson's disease with and without impulse control behaviors

Area of Science:

• Neuroimaging
• Neuroscience
• Neurology

Background:

• Impulse control behaviors (ICBs) in Parkinson's disease (PD) are linked to dopaminergic therapy and brain network alterations.
• The exact neurobiological underpinnings of ICBs in PD require further investigation.

Purpose of the Study:

• To investigate white matter microstructure differences in PD patients with and without ICBs.
• Utilize advanced diffusion MRI and magnetization transfer saturation (MT-sat) imaging for comprehensive assessment.

Main Methods:

• Compared 19 PD patients with ICBs (PD-ICBs), 18 PD patients without ICBs (PD-nICBs), and 20 healthy controls (HCs).
• Employed diffusion tensor imaging (DTI), diffusion kurtosis imaging, neurite orientation dispersion and density imaging, and MT-sat imaging.
• Analyzed data using tract-based spatial statistics (TBSS), regions of interest (ROIs), and tract-specific analysis (TSA).

Main Results:

• PD-nICBs exhibited significant white matter alterations across numerous tracts compared to HCs.
• PD-ICBs showed only partial changes in several white matter parameters.
• PD-nICBs had reduced axial kurtosis, myelin volume fraction, and orientation dispersion index in specific white matter tracts compared to PD-ICBs.

Conclusions:

• White matter microstructural differences exist between PD patients with and without ICBs.
• Alterations in myelin and axonal integrity within reward and visual-emotional processing pathways may distinguish PD-nICBs from PD-ICBs.