A Network Centered on the Visual-Motor Cortex Is Critically Involved in Postural Abnormality in Parkinson's Disease

Postural abnormality (PA) is a key motor symptom in Parkinson's disease (PD) that leads to disability and death. However, the pathophysiology underlying PA is still unknown.

The objective of this study was to explore the neural patterns behind PAs and measures toward functional restoration using repetitive transcranial magnetic stimulation (TMS) in PD.

We included cross-sectional (n = 181) and TMS-based therapy-response (n = 45) analyses of PD. Posture features, structural magnetic resonance imaging (MRI), and functional MRI data were collected. After regressing out covariates, brain maps of morphometry image and functional MRI data were compared to determine stimulation targets for the subsequent TMS sessions. Spearman's correlation analysis was conducted to explore relationships between posture features and MRI data.

PD patients with PA (PD_PA) showed a greater extent of brain atrophy and functional alterations in bilateral lingual gyri and precentral gyri than patients without PA (PD_NPA). Furthermore, the PD_PA group had decreased functional connectivity between the left lingual gyrus and the left precentral gyrus compared with the PD_NPA group. The degree of such alteration inversely correlated with posture features. After 10 sessions of excitatory neuromodulation over the bilateral lingual gyri and precentral gyri, the Verum TMS group showed significant improvement in PA. We also observed increased degree centrality of the left lingual gyrus and enhanced functional connectivity between the left lingual gyrus and left inferior parietal lobule. Those changes were correlated with the improvement of PAs.

Our study identifies a specific visual-motor integration circuitry involved in PAs of PD, where precentral gyrus and lingual gyrus are core nodes. © 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.