Data from: Cortical thickness, surface area and subcortical volume differentially contribute to cognitive heterogeneity in Parkinson's disease

Parkinson's disease (PD) is often associated with cognitive deficits,
although their severity varies considerably between patients. Recently, we
used voxel-based morphometry (VBM) to show that individual differences in
gray matter (GM) volume relate to cognitive heterogeneity in PD. VBM does,
however, not differentiate between cortical thickness (CTh) and surface
area (SA), which might be independently affected in PD. We therefore
re-analyzed our cohort using the surface-based method FreeSurfer, and
investigated (i) CTh, SA, and (sub)cortical GM volume differences between
93 PD patients and 45 matched controls, and (ii) the relation between
these structural measures and cognitive performance on six
neuropsychological tasks within the PD group. We found cortical thinning
in PD patients in the left pericalcarine gyrus, extending to cuneus,
precuneus and lingual areas and left inferior parietal cortex, bilateral
rostral middle frontal cortex, and right cuneus, and increased cortical
surface area in the left pars triangularis. Within the PD group, we found
negative correlations between (i) CTh of occipital areas and performance
on a verbal memory task, (ii) SA and volume of the frontal cortex and
visuospatial memory performance, and, (iii) volume of the right thalamus
and scores on two verbal fluency tasks. Our primary findings illustrate
that i) CTh and SA are differentially affected in PD, and ii) VBM and
FreeSurfer yield non-overlapping results in an identical dataset. We argue
that this discrepancy is due to technical differences and the subtlety of
the PD-related structural changes.