The near-term effects of brain injuries have been intensively studied. But there can be lifelong effects as well. For example, a new study shows that victims of severe traumatic brain injuries (TBI) may face a dramatically higher risk for dementia than people who suffer less severe brain injuries. Age appears to be a factor too. The study showed that people aged 41-50 who suffered a TBI had a sharply higher risk for dementia than those who suffered a TBI at a younger age.