
- With Mayo Clinic clinical neuropsychologist
Glenn Smith, Ph.D.
read biographyclose windowBiography of
Glenn Smith, Ph.D.
Glenn Smith, Ph.D.
Dr. Glenn Smith is a board-certified clinical neuropsychologist who specializes in Alzheimer's disease.
Dr. Smith, a Lincoln, Neb., native, has been with Mayo Clinic since 1990 and works with neurologists, psychiatrists, internists, social workers and nurses involved in diagnosing and providing care for people with dementia and their families.
"For Alzheimer's disease, there is currently no cure," he says. "The best "medicine" for patient and family remains education and support. Hopefully, Mayo Clinic's Alzheimer's disease Web resources contribute to compassionate care and understanding for Alzheimer's families."
Dr. Smith is a professor of psychology at College of Medicine, Mayo Clinic, a division co-chair in the Department of Psychiatry and Psychology, and principal investigator of the Mayo Alzheimer's Disease Research Center Education and Information Transfer Core. He is past president of the American Board of Clinical Neuropsychology and the Clinical Neuropsychology Division of the American Psychological Association.
Risk factors (2)
- Oophorectomy (ovary removal): A risk factor for dementia?
- Alzheimer's: Can a head injury increase my risk?
Symptoms (1)
- Sundowning: Late-day confusion
Tests and diagnosis (2)
- Rapidly progressing Alzheimer's: Something else?
- Alzheimer's test: Detection at the earliest stages
Complications (1)
- Phantosmia: What causes olfactory hallucinations?
Treatments and drugs (3)
- Folic acid supplements: Can they slow cognitive decline?
- Vitamin B-12: Can it improve memory in Alzheimer's?
- Alzheimer's nose spray: New Alzheimer's treatment?
Lifestyle and home remedies (2)
- Alzheimer's: Can a Mediterranean diet lower my risk?
- Music and Alzheimer's: Can it help?
Alternative medicine (5)
- Phosphatidylserine supplements: Can they improve memory?
- Vitamin B-12: Can it improve memory in Alzheimer's?
- Axona: Medical food to treat Alzheimer's
- see all in Alternative medicine
Coping and support (1)
- Elder care for Alzheimer's: Choosing a provider
Question
Alzheimer's: Can a head injury increase my risk?
Can a head injury cause or hasten Alzheimer's disease or other types of dementia?
Answer
from Glenn Smith, Ph.D.
The immediate effects of a head injury can include dementia symptoms, such as confusion, memory loss, and 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 dementias later in life. The greatest increase in future dementia risk seems to occur after a severe head injury that knocks you out for more than 24 hours. A moderately serious head injury that causes unconsciousness for more than 30 minutes, but less than 24 hours, also seems to increase risk to a smaller extent.
There's no evidence that a single mild head injury that doesn't knock you out, or that knocks you out for less than 30 minutes, increases your risk of dementia. However, repeated mild injuries may increase 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. A head injury in such a person would increase his or her risk further.
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.
Next questionSundowning: Late-day confusion
- DeKosky ST, et al. Traumatic brain injury - Football, warfare, and long-term effects. New England Journal of Medicine. 2010;363:1293.
- Kumar V, et al. Healthy brain aging: Effect of head injury, alcohol and environmental toxins. Clinics in Geriatric Medicine. 2010;26:29.
- Magnoni S, et al. New perspectives on amyloid-beta dynamics after acute brain injury. Archives of Neurology. 2010;67:1068.
- Chen AJ-W, et al. Traumatic brain injury: From bench to bedside to society. Neuron. 2010;66:11.


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