Papers of the Week

We want to investigate degenerative changes of white matter volume (WMV) and grey matter volume (GMV) in individuals after a spinal cord injury (SCI). Published studies of whole-brain voxel-based morphometry (VBM) comparing SCI patients with controls published between 2006 and March 1st, 2018 were collected by searching PubMed, Web of Science, and EMBASE databases. Voxel-wise meta-analyses of GMV and WMV differences between SCI patients and controls were performed separately using seed-based d mapping. Twelve studies with 12 GMV datasets and 9 WMV datasets yielded a total of 466 individuals (190 SCI patients and 276 controls) that were included in this meta-analysis. Compared with controls, SCI patients showed GMV atrophy in sensorimotor system regions including the bilateral sensorimotor cortex (S1 and M1), the supplementary motor area (SMA), paracentral gyrus, thalamus, and basal ganglia, as well as WMV loss in the corticospinal tract. GMV aberrancies were also demonstrated in brain regions responsible for cognition and emotion, such as the orbitofrontal cortex (OFC) and the left insula. Additionally, GMV in both the bilateral S1 and the left SMA was positively correlated with the time span after the injury. Anatomical atrophy in cortical-thalamic-spinal pathways suggested that SCIs may result in degenerative changes of the sensorimotor system. Furthermore, OFC and insula GMV abnormalities may explain symptoms such as neuropathic pain and potential cognitive-emotional impairments in chronic SCI patients. These findings indicate that anatomical brain magnetic resonance imaging (MRI) protocols could be neuroimaging biomarkers for interventional studies and treatments.