Can a head injury cause or hasten Alzheimer's disease or other types of dementia?
Answer From Jonathan Graff-Radford, M.D.
The immediate effects of a head injury can include symptoms that are also seen in dementia, such as confusion and memory loss, as well as changes in speech, vision and personality. Depending on the severity of your injury, these symptoms may clear up quickly, last a long time or never go away completely.
However, such symptoms that begin soon after your injury generally don't get worse over time as happens with Alzheimer's disease.
Certain types of head injuries, however, may increase your risk of developing Alzheimer's disease or other types of dementias later in life. The factors that seem to affect your risk include your age at the time of the injury and the severity of the injury.
More-severe head injuries may increase your risk of developing Alzheimer's disease. And sustaining a head injury when you're older, around age 55, may also increase your risk. Repeated mild injuries also may increase your risk of future problems with thinking and reasoning.
You're likely at greatest risk of developing dementia or Alzheimer's later in life, post-head injury, if you also have other risk factors. For example, carrying one form of the apolipoprotein E (APOE) gene increases the risk of Alzheimer's in any individual.
It's important to note that many people who sustain a severe head injury never develop Alzheimer's disease or later dementia. More research is needed to understand the link.
April 20, 2019
Jonathan Graff-Radford, M.D.
See more Expert Answers
- Traumatic brain injury: Hope through research. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/tbi/detail_tbi.htm. Accessed July 13, 2017.
- Evans RW, et al. Postconcussion syndrome. https://www.uptodate.com/contents/search. Accessed July 13, 2017.
- Wright CB. Etiology, clinical manifestations, and diagnosis of vascular dementia. https://www.uptodate.com/contents/search. Accessed July 13, 2017.
- Corrigan F, et al. Pumping the brakes: Neurotrophic factors for the prevention of cognitive impairment and dementia after traumatic brain injury. Journal of Neurotrauma. 2017;34:971.
- Gardner RC, et al. Dementia risk after brain versus non-brain trauma: The role of age and severity. JAMA Neurology. 2014;71:1490.
- Gardner RC, et al. Epidemiology of mild traumatic brain injury and neurodegenerative disease. Molecular and Cellular Neuroscience. 2015;66(Pt B):75.