MRI Signal Characteristics of Conus Medullaris Aids Prediction of Bladder Outcome in Traumatic Conus Medullaris Syndrome

Background: Neurogenic bladder dysfunction is a common and serious consequence of traumatic conus medullaris syndrome (T-CMS). Despite its clinical importance, predictive data for bladder outcomes after T-CMS remain limited. This study aimed to identify predictors of neurogenic bladder dysfunction at ≥2 years post-injury.Methods: We retrospectively reviewed 39 patients with acute T-CMS treated at a single level I trauma center from 2004–2017 who underwent spinal surgery and had ≥2 years of follow-up. Bladder function at 2 years was categorized as complete dysfunction, incomplete dysfunction, or normal. Potential predictors included demographic factors, injury mechanisms, ASIA Impairment Scale grades, MRI timing, fracture level and type, canal diameter, occupying ratio, conus signal change (normal, edema, or edema with hemorrhage), edema length, time to surgery, and surgical approach. Univariate and multivariate analyses were performed.Results: At final follow-up, 14 patients (35.9%) had complete bladder dysfunction, 12 (30.8%) had incomplete dysfunction, and 13 (33.3%) had normal function. Multivariate analysis identified edema with hemorrhage in the conus medullaris as the only independent predictor of bladder dysfunction.Conclusions: Bladder dysfunction is highly prevalent after T-CMS. Hemorrhagic edema in the conus medullaris significantly increases the risk of long-term neurogenic bladder dysfunction.