Session Information
Date: Thursday, June 8, 2017
Session Title: Parkinson's Disease: Neuroimaging And Neurophysiology
Session Time: 1:15pm-2:45pm
Location: Exhibit Hall C
Objective: . The objective of this study was to determine how white matter (WM) microstructure is altered in early tremor dominant (TD) and postural instability and gait difficulty (PIGD) subtypes of Parkinson’s disease (PD) before administration of medications.
Background: One of the common classifications in PD is TD and PIGD subtypes. To date, little is known about the white matter (WM) microstructural features of the two subtypes in early drug naïve PD.
Methods: 52 TD and 13 PIGD patients with consistent subtypes at baseline and one-year follow-up and 61 well-matched controls underwent MRI scanning at baseline. Whole-brain voxel-based morphometry (VBM) and tract-based special statistics (TBSS) were used to compare gray matter (GM) and WM features between TD, PIGD, and control groups.
Results: TD patients showed increased fractional anisotropy (FA), but decreased radial and axial diffusivities (RD and AD) in multiple projection, association, and some commissural WM tracts, compared with PIGD patients or controls. Correlating the DTI values of the significant tracts with general motor severity in PD indicated mild-to-moderate correlations of FA and RD in the genu of the corpus callosum in TD patients, but strong correlations of FA and RD in multiple association tracts, including bilateral inferior longitudinal fasciculi, in PIGD patients. These results cannot be explained by GM changes.
Conclusions: Increased FA but decreased diffusivities in TD patients suggest neural compensation. In contrast, PIGD patients with similar disease stage and duration had more WM degradation. Findings from our study demonstrate differentiable WM features between TD and PIDG subtypes in early drug naïve PD patients.
References: 1. Stebbins G, Goetz C, Burn D, Jankovic J, Khoo T, Tilley B. How to identify tremor dominant and postural instability/gait difficulty groups with the movement disorder society unified Parkinson’s disease rating scale: comparison with the unified Parkinson’s disease rating scale. Movement Disorders. 2013;28(5):668-670.
2. Helmich R, Hallett M, Deuschl G, Toni I, Bloem B. Cerebral causes and consequences of parkinsonian resting tremor: a tale of two circuits? Brain 2012;135(Pt 11):3206-3226.
To cite this abstract in AMA style:
M.-C. Wen, H. Heng, Z. Lu, Z. Xu, L.L. Chan, E.K. Tan, L. Tan. White Matter Microstructural Features of Motor Subtypes in De Novo, Drug Naïve Parkinson’s Disease Patient [abstract]. Mov Disord. 2017; 32 (suppl 2). https://www.mdsabstracts.org/abstract/white-matter-microstructural-features-of-motor-subtypes-in-de-novo-drug-naive-parkinsons-disease-patient/. Accessed July 18, 2025.« Back to 2017 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/white-matter-microstructural-features-of-motor-subtypes-in-de-novo-drug-naive-parkinsons-disease-patient/