Cortical thickness and Subcortical volume changes differ between Parkinson disease subtypes

Abstract BACKGROUND : To explore the different patterns of cortical thickness and subcortical volume changes between Parkinson disease (PD) subtypes by structural magnetic resonance imaging (MRI). METHODS: We enrolled 48 clinically confirmed PD patients, including 23 tremor dominant (TD) and 25 postural instability gait dominant (PIGD) subtypes, and 32 matched healthy control (HC) volunteers were also collected, all subjects underwent 3.0 Tesla high-resolution structural MRI scanning. Cortical thickness and subcortical volumetric analysis were estimated using an automated Computational Anatomy Toolbox (CAT12) toolbox. Results: Compared with the HC group, PIGD patients had significantly thinning cortical thickness in multiple brain regions, such as bilateral inferiorparietal, paracentral, precuneus, superiorfrontal, caudalmiddlefrontal, posteriocingulate, parahippacampal, lateraloccipital and right superiortemporal, supramarginal and parsorbitals. TD patients had slightly thinning focal cortical thickness in bilateral posteriocingulate, left inferioparietal and right precuneus. PIGD patients had thinner cortical thickness in left caudalmiddlefrontal, parahippacampal and right isthmuscingulate and lateraloccipital than TD patients. In addition, subcortical volume atrophy was identified in the bilateral hippocampus and bilateral amygdala of the patients with PIGD, only right hippocampus changes were found in the TD group. Moreover, the largest area under the ROC curve of hippocampus and atrophy ratio, cortical thickness in region of interest (ROI) and combination of hippocampus ratio, atrophy ratio and cortical thickness in ROIs which for distinguish PIGD from TD were 0.733, 0.912 and 0.999 respectively. Conclusions: Morphometric abnormalities were greater in the PIGD than that in the TD subtype, the disparate patterns of cortical and subcortical degeneration had a potential possibility to distinguish the PD subtypes by MRI perspective in clinical practice.