Indicators of complicated mild TBI predict MMPI-2 scores after 23 years

Primary objective: Research suggests that post-concussive syndrome may become persistent after mild traumatic brain injury (mTBI). The aim of this study was to investigate determinants of subjective complaints, characteristic for post-concussive syndrome, 23 years after mTBI. Research design: The study was a follow-up after a prospective head injury study at a general hospital in Norway. Methods and procedures: Ninety-seven patients were assessed with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) 23 years after sustaining primarily mTBI. Main outcomes and results: A good overall outcome was found with scores close to the normative mean, average length of education and normal employment rate. However, the patients that sustained complicated mTBI showed somewhat more pathological scores, well-matched with mild post-concussive syndrome. The most important predictors of poor outcome were a combination of post-traumatic amnesia 30 minutes and EEG pathology within 24 hours after TBI. No influence of pre- and post-injury risk factors on current MMPI-2 profiles was found. Conclusions: The results are in line with previous research findings and support the notion of potentially differential impact of uncomplicated vs. complicated mTBI. The findings suggest that complicated mTBI may cause subtle chronic symptoms typical of post-concussive syndrome.