Brain Morphology in Subacute Spinal Cord Injury: Insights Into Functional Recovery Across Brain Networks

BACKGROUND: Spinal cord injury (SCI) induces widespread structural brain reorganization extending beyond primary sensorimotor areas, yet the extent to which brain morphometry across the whole brain can inform functional recovery alongside established clinical variables remains unclear.

METHODS: We retrospectively analyzed 79 individuals with SCI from the SwiSCI Inception Cohort who underwent clinically acquired brain MRI during inpatient rehabilitation. The outcome measure was the Spinal Cord Independence Measure (SCIM-III) assessed at discharge. Two cross-validated elastic-net regression models were evaluated: a clinical-only model to confirm the predictive value of established clinical variables and a combined model integrating clinical variables with whole-brain cortical gray matter volumes across different functional networks.

RESULTS: Both models achieved comparable predictive performance. However, in the combined model, a distributed set of cortical regions (including associative parietal and primary sensorimotor areas) was consistently identified by the model as potentially relevant to functional independence at discharge. Some of these regions were also significantly associated with neurological severity in the subacute stage, supporting their clinical relevance.

CONCLUSION: In our sample, brain morphometry did not provide incremental predictive information beyond established clinical variables. Nonetheless, the combined model indicated a distributed set of cortical regions across sensorimotor and higher-order networks showing consistent associations with functional independence at discharge, providing insights into the neural correlates of SCI recovery and candidate targets for future hypothesis-driven neuroimaging research.