438 Lesion Combination on Susceptibility-Weighted MRI Predicts Functional Recovery After Diffuse Axonal Injury

INTRODUCTION: Early prediction of long-term functional outcome after diffuse axonal injury (DAI) remains controversial. METHODS: In a retrospective observational study, axonal injuries on MRI were correlated with long-term functional outcome. The predictive value of poor functional outcome (GOSE < 5) was determined by ROC analysis for clinical factors and location of combinations of DAI lesions in the connectome. RESULTS: Over a 10-year period, 451 patients underwent MRI within 30 days of severe blunt TBI of which 322 (71.4%) survived to = 6-month clinical follow-up. The mean age was 38.4 and 242 (75%) patients were male. Mechanisms of injury were motor vehicle crash (53%) and falls (26%). Mean Glasgow coma scale (GCS) score was 4.7. At 6-24 months, quality MRI and functional outcome data were available for 213 and 104 patients, respectively. The best single-area predictors of early and late long-term functional outcome were the ventral midbrain (AUC6mo 0.65 (95% CI 0.56-0.74), p = 0.010) and dorsal pons (AUC24mo 0.68 (95% CI 0.51-0.86) p = 0.001). The best multiple-lesion predictors of poor long-term functional outcome (GOSE < 5) were dorsal pons and splenium of corpus callosum (AUC24mo 0.92 (95% CI 0.84-0.99), p < 0.0001) and the dorsal and ventral pons (AUC24mo 0.91 (95% CI 0.79-1.00), p < 0.0001). The strength of these combinations’ predictive value was not improved by considering three or more areas. The 6-area cluster of internal capsule, corpus callosum genu, body, and splenium; and dorsal and ventral midbrain lesions was a good predictor of outcome at 24 months (AUC24mo 0.82 (95% CI 0.66-0.98), p < 0.0001). CONCLUSIONS: In patients with severe TBI, the strongest predictors of poor long-term functional outcome were combined lesions in the splenium and dorsal pons and the dorsal and ventral pons.