This new Chinese paper compared " tremor-dominant and postural instability-gait difficulty (PIGD) Parkinson's disease subtypes". They found related volume losses as there were in our 202 study, but imaging results were more detailed.
They also found that the latter group had severe gray matter loss, compared with normal, but the tremor dominant did not differ from normal. We know that MSA patients have similar postural and gait difficulties. This is why I think that the MSA patients have also corresponding gray matter loss and perhaps this could be seen in blood tests, perhaps p217Tau.

Correlation between basal ganglia nuclei and cortical gray matter volume changes in different motor subtypes of Parkinson's disease

Jun Lu ¹, Xinyue Huangfu, Yumei Zhang, Yan Nan, Minhai Wang, Weilan Zhang, Chengwei Wang

Affiliations Expand

• PMID: 40203236

DOI: 10.1097/WNR.0000000000002155

Abstract

Explore the correlation between basal ganglia nuclei and cortical gray matter volume changes in tremor-dominant and postural instability-gait difficulty (PIGD) Parkinson's disease subtypes for Parkinson's disease diagnosis and individualized treatment. High-resolution 3D-T1WI MRI data from 35 tremor-dominant and 30 PIGD patientsand 35 healthy controls were analyzed. Voxel-based morphometry identified gray matter volume differences. Automated basal ganglia segmentation quantified subcortical volumes, followed by multivariate analysis of covariance and Spearman correlation analyses. Compared with healthy control, patients with PIGD exhibited severe gray matter loss (P < 0.0001), while tremor-dominant showed nonsignificant reductions. Subcortically, different basal ganglia volumes were atrophied in the tremor-dominant and PIGD groups compared with the healthy control (P < 0.05). PIGD demonstrated greater left putamen atrophy than tremor-dominant (P < 0.05). Spearman correlation analysis revealed that the volume of the right globus pallidus was positively correlated with that of the left medial and lateral cingulate gyrus in patients with tremor-dominant (r = 0.35, P = 0.04); and between the left globus pallidus volume and the right superior temporal gyrus volume in patients with PIGD (r = 0.47, P = 0.01). Compared with the tremor-dominant subtype, the PIGD subtype exhibits more severe GM atrophy, with different basal ganglia volume changes across subtypes. These altered anatomical features and the correlation between degeneration of the basal ganglia region and cortical gray matter changes may provide insights into the differential functional changes in patients with different motor subtypes and help to elucidate the underlying pathologic mechanisms.