Traumatic Brain Injury (TBI) may be linked to higher risk of dementia in older age. The significance of the risk is seen even after 30 years of TBI.

‘The risk of dementia becomes higher for those with a severe TBI or multiple TBIs, compared to those with one mild TBI.’

In the first year after TBI, the risk of dementia is increased by 4- to 6-fold, the researchers found. Thereafter, the risk decreased rapidly but was still significant more than 30 years after the TBI. Overall, the risk of dementia diagnosis was increased by about 80 percent during a mean follow-up period of 15 years. The risk of dementia was higher for those with a severe TBI or multiple TBIs and was similar in men and women. Because the development of dementia can be a risk factor for accidents resulting in TBI, it’s likely that in some cases, the onset of dementia preceded the TBI, so the researchers caution against making causal inferences. 




"The findings of this study suggest an existence of a time- and dose-dependent risk of developing dementia more than 30 years after TBI," the authors say. "To our knowledge, no previous prospective study with similar power and follow-up time has been reported."
Source-Eurekalert