Can an MRI Predict Who Will Get Alzheimer's Disease?

Can imaging scans of the brain predict who will go on to get Alzheimer's disease? There's a condition called mild cognitive impairment where a person has mild memory impairment and difficulty processing information, but they're still able to function appropriately. They may seem relatively normal but a little more confused and forgetful. The problem is more than half of all people with mild cognitive impairment go on to develop full-blown dementia. But which ones?

Can Scans of the Brain Predict Future Dementia?

A team of researchers at the University of California at San Diego School of Medicine believe MRI scans of the brain are useful for distinguishing which people with mild cognitive impairment will develop Alzheimer's dementia. They did serial head MRI scans on almost 700 older adults, some with mild cognitive impairment, some with Alzheimer's disease - as well as a group of healthy adults. They found that thinning of the cerebral cortex the portion of the brain involved in memory and higher cognitive processing was a good marker for future progression to Alzheimer's disease, which is easy to read on MRI.

They did repeat MRI scans of the brain a year later to look at how the thickness of the cerebral cortex had changed in these patients over time and found this change in cortical thickness to be a good marker for future progression to dementia. Not surprisingly, people with rapid thinning of their cerebral cortex over time are more likely to have dementia later as their cerebral cortex thins out and atrophies. Brain atrophy is a common feature of Alzheimer's disease.

MRI Scans of the Brain and Mild Cognitive Impairment

People who are experiencing cognitive and memory problems usually undergo a workup that includes a head MRI, but the head MRI is mainly used to rule out other treatable conditions that cause symptoms of dementia. Now it appears that MRI scans of the brain could be useful for predicting whether people with mild cognitive impairment will go on to develop more serious memory problems later. This would allow families the chance to better plan for the future. Plus, MRI scans of the brain are a safe procedure that doesn't involve exposure to radiation, which is a good thing for both patients and family.

References: "Using MRI, Researchers May Predict Which Adults Will Develop Alzheimer's"
Merck Manual. Eighteenth edition. 2006.