October 29, 2019
By Megan Brooks
NEW YORK (Reuters Health) - Memory loss due to traumatic brain injury (TBI) can be distinguished from Alzheimer's disease (AD) using magnetic resonance imaging (MRI), according to a new study.
The study found that older adults with a history of TBI and memory loss show abnormalities on MRI that are different from age-related changes and distinct from the usual patterns seen in AD.
"That's important because it suggests that in older individuals with memory problems, this pattern could identify those individuals that are having memory problems from TBI and it can prevent a misdiagnosis of Alzheimer's disease," Dr. Cyrus Raji of the Mallinckrodt Institute of Radiology, Division of Neuroradiology, Washington University in St. Louis, told Reuters Health by phone.
The study was published online October 23 in the Journal of Alzheimer's disease.
Dr. Raji and colleagues at the University of California, Los Angeles, took a look back at MRI scans from 40 patients (mean age, 67.7 years) referred for cognitive complaints who had a history of TBI. They were screened for history of known dementia or other disorders that might influence cognition.
Each patient had an MRI that included a 3D volumetric sequence analyzed with Neuroreader volumetric brain assessment software. Brain volumes in the 40 participants were compared to a normative database to determine the extent of atrophy.
Results showed that TBI caused the most damage to a brain region known as the ventral diencephalon, which is associated with learning and emotions. TBI caused the least amount of atrophy in the hippocampus, the brain region involved in memory and emotions and that is most impacted by dementia.
"The fact that we did not find predominant hippocampal or temporal-parietal atrophy in this group compared to other regions suggests that TBI-related brain damage is distinct, and that the mechanisms of TBI-related cognitive decline are potentially distinguishable from those for AD and other dementias," write the researchers.
"I think in older individuals with memory loss there tends to be a default toward jumping to the AD diagnosis," Dr. Raji told Reuters Health. Being able to distinguish TBI-related memory loss from AD-related memory loss has obvious benefits for patients, he added.
"In a patient with memory loss and TBI where the hippocampus is normal, but these other brain regions are abnormal, we now know that can be affected by TBI and you have essentially prevented an AD misdiagnosis," said Dr. Raji. "No one wants to hear that they have head trauma-related damage, but it's not nearly as anxiety inducing as the AD diagnosis."
The study was supported by McLoughlin Cognitive Health Gift Fund. Dr. Raji has received consulting fees from Brainreader ApS, which makes Neuroreader software.
J Alzheimers Dis 2019.
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