Is Head Injury Causing Dementia? MRI Might Show

MONDAY, Oct. 28, 2019 (HealthDay News) -- When a loved one shows signs of dementia, sometimes a head injury is the cause and MRI scans can help prevent a misdiagnosis of Alzheimer's, researchers report.

As many as 21% of older adults with dementia may be misdiagnosed with Alzheimer's disease, a previous study found. Up to 40% of dementias are caused by conditions other than Alzheimer's disease, according to the Alzheimer's Association.

A misdiagnosis can be devastating for patients and their families, and result in patients not receiving appropriate treatment or taking part in clinical trials that could benefit them, according to the authors of this new study.

It included 40 patients, average age 68, who'd suffered a traumatic brain injury (TBI) and later developed memory problems. The patients underwent brain MRI scans, which were analyzed with a software program.

"We already knew that MRIs can reveal subtle abnormalities in patients with neurological disorders, such as Alzheimer's," said study author Dr. Somayeh Meysami, a postdoctoral clinical research fellow in cognitive and behavioral neurology at the University of California, Los Angeles.

"The purpose of our study was to evaluate whether MRI also could reveal distinct abnormalities in traumatic brain injury. And, if we could identify such a pattern, it would lead to improved diagnosis of TBI-related memory loss from other causes of dementia," Meysami explained in a university news release.

The MRI scans revealed that in the TBI patients, most of the brain damage was in a region called the ventral diencephalon, and the least amount of damage was in the hippocampus. The ventral diencephalon is involved in learning and emotions, while the hippocampus is involved in memory and emotions and is the region of the brain most impacted by Alzheimer's disease.

According to study co-author Dr. Cyrus Raji, the method the team used to "measure brain volumes in these individuals is useful because it can be applied on the same type of MRI scans we obtain in the clinic with no special type of imaging required." Raji is an assistant professor of radiology at Washington University in St. Louis.

The study was published recently in the Journal of Alzheimer's Disease.

About 2.9 million Americans experienced a TBI in 2014, and the rates are highest among people aged 75 and older, according to the U.S. Centers for Disease Control and Prevention.

More information

The American Academy of Family Physicians has more on traumatic brain injury.