Spinal cord diffusion tensor imaging predicts balance in degenerative cervical myelopathy.

INTRODUCTION: Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults and a major contributor to balance impairment and gait instability. Surgical decompression halts disease progression, but predicting post-surgical functional recovery remains challenging. Conventional MRI poorly reflects spinal cord microstructural integrity, limiting its ability to quantify sensorimotor deficits or predict outcomes. Diffusion tensor imaging (DTI) provides quantitative measures of tract-specific microstructure and may serve as a more sensitive biomarker for functional impairment and recovery in DCM. METHODS: In a prospective longitudinal cohort of 57 DCM patients undergoing surgical decompression, pre-operative spinal cord DTI was acquired at 3T. DTI metrics: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD), and filtered apparent diffusion coefficient (Daxial) were extracted from dorsal, lateral, and ventral funiculi and gray matter at the C2 level. Functional outcomes included the Berg Balance Scale (BBS), Functional Gait Assessment (FGA), 10-Meter Walk Test (10MWT), and Eyes Closed Feet Together (ECFT) test, assessed pre-operatively and at 3 months post-surgery. General linear models examined baseline DTI-function associations; linear mixed-effects models assessed DTI prediction of post-operative improvement. Covariates were selected by pre-screening at p < 0.10. RESULTS: Dorsal column FA (p = 0.034, q = 0.086) and RD (p = 0.025, q = 0.086) were associated with baseline BBS. Dorsal column MD (p = 0.010, q = 0.026) and RD (p = 0.009, q = 0.026) predicted post-operative BBS improvement. Lateral funiculi Daxial (p = 0.008, q = 0.038) predicted post-operative FGA improvement. Gray matter FA was associated with baseline FGA (p = 0.014, q = 0.070). Ventral funiculi metrics showed no significant associations. Forty-nine participants completed 3-month follow-up. CONCLUSION: Pre-operative C2-level DTI metrics demonstrate tract-specific associations with balance and gait function in DCM. Dorsal column microstructure was most strongly associated with static balance, while lateral funiculi and gray matter microstructure related more closely to dynamic balance and gait. These findings support spinal cord DTI as a quantitative imaging biomarker for functional prognostication and post-surgical outcome prediction in DCM.