Link Between Major Traumatic Brain Injury, Dementia Examined

Major traumatic brain injury (TBI), defined as a diagnosis of traumatic intracranial hemorrhage and hospital length of stay of three or more days, is associated with an increased risk for incident dementia, although the association is not statistically significant after adjustment for confounders, according to a study published online May 11 in Neurology.

Rahul Raj, M.D., Ph.D., from Helsinki University Hospital in Finland, and colleagues examined whether TBI increases the risk for dementia after adjustment for other relevant risk factors in a national prospective longitudinal cohort study. Data were included for 31,909 participants, aged 25 to 64 years during 1992 to 2012, of whom 288 and 406 were hospitalized due to a major and minor TBI, respectively.

During a median follow-up of 15.8 years, there were 976 incident dementia cases. The researchers found that hospitalization due to major TBI, but not minor TBI, increased the risk for dementia after adjustment for age and sex (hazard ratio, 1.51; 95 percent confidence interval, 1.03 to 2.22). The association was attenuated after further adjustment for educational status, smoking status, alcohol consumption, physical activity, and hypertension (hazard ratio, 1.30; 95 percent confidence interval, 0.86 to 1.97). Alcohol consumption and physical activity were the factors most strongly attenuating the association between major TBI and dementia.

“Considering that there is no cure for dementia or TBI, the results of our study suggest that prevention of other dementia risk factors such as excess alcohol consumption and physical inactivity could possibly reduce the risk of dementia in people with major TBI,” Raj said in a statement.

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