The hindbrain and cortico-reticular pathway in adolescent idiopathic scoliosis

AIM: To characterise the corticoreticular pathway (CRP) in a case -control cohort of adolescent idiopathic scoliosis (AIS) patients using high -resolution slice -accelerated readoutsegmented echo -planar diffusion tensor imaging (DTI) to enhance the discrimination of small brainstem nuclei in comparison to automated whole -brain volumetry and tractography and their clinical correlates. MATERIALS AND METHODS: Thirty-four participants (16 AIS patients, 18 healthy controls) underwent clinical and orthopaedic assessments and brain magnetic resonance imaging (MRI) on a 3 T MRI machine. Automated whole -brain volume -based morphometry, tract -based spatial statistics analysis, and manual CRP tractography by two independent raters were performed. Intra-rater and inter -rater agreement of DTI metrics from CRP tractography were assessed by intraclass correlation coefficient. Normalised structural brain volumes and DTI metrics were compared between groups using Student 's t -tests. Linear correlation analysis between imaging parameters and clinical scores was also performed. RESULTS: AIS patients demonstrated a signi ficantly larger pons volume compared to controls ( p =0.006). Signi ficant inter -side CRP differences in mean ( p =0.02) and axial diffusivity ( p =0.01) were found in patients only. Asymmetry in CRP fractional anisotropy signi ficantly correlated with the Cobb angle ( p =0.03). CONCLUSION: Relative pontine hypertrophy and asymmetry in CRP DTI metrics suggest central supranuclear inter -hemispheric imbalance in AIS, and support the role of the CRP in axial muscle tone. Longitudinal evaluation of CRP DTI metrics in the prediction of AIS progression may be clinically relevant. (c) 2024 The Authors. Published by Elsevier Ltd on behalf of The Royal College of Radiologists. This is an open access article under the CC BY -NC -ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).