Association of injury severity, MRI-results and ApoE genotype with 1-year outcome in mainly mild TBI: A preliminary study

Primary objective: To study the ability of MRI findings, apolipoprotein E (ApoE) genotype, the Glasgow Coma Score (GCS) and duration of post-traumatic amnesia (PTA) to predict the 1-year outcome in traumatic brain injury (TBI). Research design: A prospective study in unselected emergency room patients with an acute TBI, followed for 1 year. Methods and procedures: Thirty-three consecutive patients were studied. The TBI severity was assessed with GCS and duration of PTA. Brain MRI scans were obtained within 1 week post-injury. The ApoE genotypes were determined by standard methods. The outcome was evaluated with the Head Injury Symptom Checklist and the Glasgow Outcome Scale (extended) 1 year after the injury. The prognostic value of the explanatory variables was evaluated with multiple linear regression analysis. Main outcomes and results: The presence of traumatic axonal injury lesions or contusions in MRI and duration of PTA were independent predictors of poor outcome. The ApoE genotype and GCS were not associated with outcome. Conclusions: In multivariate models, the duration of PTA and acute MRI are the best predictors of 1-year outcome in TBI, whereas the prognostic values of GCS and ApoE are modest. The dominating role of GCS in assessing TBI severity should be questioned.