Brain morphological changes in type 2 diabetes patients with painful peripheral neuropathy

We investigates changes in brain volume and cortical thickness in patients with type 2 diabetes mellitus (T2DM) and peripheral neuropathy (DPN), particularly those with neuropathic pain. 105 participants were divided into three groups: T2DM (n = 26), T2DM with DPN (n = 42), and healthy controls (HCs, n = 37). The DPN group was further divided into painless (n = 22) and painful (n = 20) subgroups. Participants underwent clinical neuropsychological testing, electromyography, and brain MRI scans. Voxel-based morphometry was used to analyze gray matter volume (GMV) and cortical thickness. Associations between morphological changes and clinical/neuropsychological indicators were assessed. Average cortical thickness of the three patient subgroups was significantly reduced compared to the HCs. GMV loss in the DPN_ pain group was confined to the cerebellum, right putamen/pallidum, and caudate, while GMV increased in the brainstem. Multiple regression analysis showed correlations between brain regions and factors such as cholesterol levels, neuropathic pain severity, and nerve amplitudes (P < 0.001). The volume of right lateral geniculate nucleus volume was linked to the DN4 score (r = 0.593, P = 0.015) and onset age (r = -0.541, P = 0.031). Specific brain regions and the cortices are more vulnerable to the effects of neuropathic pain and peripheral nerve damage.