Reorganization of the brain in spinal cord injury: a meta-analysis of functional MRI studies

Purpose Reorganization of the brain is considered the key mechanism of functional recovery in patients after spinal cord injury (SCI). This meta-analysis assessed abnormal brain activation in SCI patients to understand the pattern of reorganization in the brain after SCI. Methods Functional magnetic resonance imaging (fMRI) studies that compared SCI patients with controls and were published before August 30, 2018, were extracted from the PubMed, Web of Science, and EMBASE databases. Voxel-wise whole-brain meta-analysis and region-of-interest meta-analysis of group differences were separately performed. Then, meta-regression analysis was conducted with several clinical characteristics as regressors. Results Sixteen studies that met the inclusion criteria were identified. Compared with control individuals, SCI patients showed increased activation in the sensorimotor cortex in both whole-brain and region-of-interest (ROI) analyses. In addition, whole-brain meta-analysis revealed increased activation in the cerebellum, and this increase was positively correlated with lesion level and injury severity. Conclusion Our results demonstrated that reorganization occurred mainly in the sensorimotor system of the brain after SCI, implying that brain functions involved in sensorimotor demands can still be preserved in this condition. These findings provide opportunities for future studies in terms of therapeutic strategies and prognosis assessment.