MRI scans show structural brain changes in people at risk for Alzheimer’s disease

People at risk of developing Alzheimer’s disease exhibit a specific structural change in the brain that can be visualized by MRI, a study by neuroscientists at Chicago’s Rush University Medical Center finds. The results may help identify those who would most benefit from early intervention.

“One of the main challenges in the field of Alzheimer’s disease is identifying individuals at risk of developing the disease so that therapeutic interventions developed in the future can be given at the earliest stage, before symptoms begin to appear,” said Sarah George, a graduate student who coauthored the study with Leyla deToledo-Morrell, Ph.D., director of the graduate program in neuroscience at Rush University Medical Center.

Structural imaging techniques can be used to identify people at risk for developing Alzheimer’s disease, according to deToledo-Morrell, also a professor of neurological sciences at the Graduate College of Rush University.

The researchers followed 52 individuals with mild cognitive impairment over a period of six years. Mild cognitive impairment is thought to be a precursor of Alzheimer’s disease and other forms of dementia. Patients with this condition can exhibit memory decline known as amnestic mild cognitive impairment. Twenty-three of the study participants progressed to Alzheimer’s disease.

The researchers used MRI to look for structural changes in the substantia innominata (SI), a region deep within the brain that sends chemical signals to the cerebral cortex, the brain’s outer layer that is largely responsible for reasoning, memory, and other higher functions. Although no structural changes were found in the SI between the two groups, the MRI showed a thinning of the cortical areas that receive strong input from the SI in those who went on to develop Alzheimer’s disease.

“Since we were able to distinguish those who progressed to Alzheimer’s disease compared with those who remained stable, we believe that MRI techniques that examine patterns of structural alterations provide a sensitive biomarker for detecting risk of Alzheimer’s disease,” George said.