Neuromorphological Alterations in the Somatosensory System of Adolescent Idiopathic Scoliosis: A Systematic Review of Magnetic Resonance Imaging Studies

Background/Objectives: This systematic review synthesizes MRI evidence to characterize neuromorphological alterations in somatosensory and vestibular brain regions among adolescents with idiopathic scoliosis (AIS). Methods: This systematic review was conducted in accordance with the PRISMA 2020 guidelines. We systematically searched five databases from inception to January 2026 for case–control MRI studies comparing AIS patients (10–18 years) with healthy controls. Two reviewers independently screened studies, extracted data, and assessed the risk of bias using the Newcastle–Ottawa Scale. Results: Across 15 studies (1270 participants), AIS patients demonstrated consistent neuromorphological alterations: (1) lower cerebellar tonsil position (0.9–2.8 mm below baseline), with ectopia incidence correlating with curve severity; (2) cortical thickening in bilateral medial regions but thinning in left paracentral areas; (3) left-dominant white matter volume increases and impaired microstructure in the corpus callosum; and (4) left-sided vestibular morphological changes, including a more vertical semicircular canal. Conclusions: AIS is associated with consistent neuromorphological alterations in key somatosensory and vestibular regions, supporting a potential neuroanatomical basis for impaired sensorimotor integration in its pathogenesis. It should be noted that substantial heterogeneity among the included studies prevented a meta-analysis, and the cross-sectional design limits causal interpretations Registration: This systematic review was registered in PROSPERO (CRD42024577195).