January 30, 2018

Study Finds Gender Differences in Mild Cognitive Impairment

Jessica CaldwellBy Jessica Z.K. Caldwell, Ph.D.

Women are more likely than men to get Alzheimer’s disease, and often show worse symptoms. On the other hand, women perform better than men on measures of memory that are often used to detect Alzheimer’s disease, such as learning a list of words. The reasons for this discrepancy are unclear, and the answers may be key to developing disease treatments.

Scientists take a closer look

A study conducted at Cleveland Clinic Lou Ruvo Center for Brain Health examined gender differences in people with Mild Cognitive Impairment (MCI). MCI is a pre-dementia stage during which memory difficulties exist, but have not yet made a major impact on daily life. Focusing on MCI allows us to examine early disease symptoms, which may be most responsive to new treatments.

Our study looked at more than 700 men and women participating in a large national project called the Alzheimer’s Disease Neuroimaging Initiative (ADNI). ADNI includes several types of brain scans. One type, called amyloid imaging, can show whether a person has buildup of a substance called amyloid in the brain. The presence of amyloid buildup is a biomarker — or biological signature — of Alzheimer’s disease. In other words, if amyloid is present, an individual has MCI due to Alzheimer’s disease.

What they found

We looked at memory performance in men and women with MCI due to Alzheimer’s disease or other causes, based on their amyloid brain imaging. We found that in MCI due to Alzheimer’s disease, both men and women showed poor memory for a list of words. However, in MCI not due to Alzheimer’s disease, women showed better memory than men. This effect could not be explained by age.

This finding is important because it shows that Alzheimer’s disease may remove the memory advantage that women typically have over men, even before the dementia stage. While more studies are needed, this finding might begin to explain how women are more vulnerable to the effects of Alzheimer’s disease.

What’s next?

Our neuropsychology team at the Lou Ruvo Center for Brain Health will continue to study ways that Alzheimer’s disease impacts men’s and women’s brains differently. A generous donation from The Women’s Alzheimer’s Movement, headed by Maria Shriver, will help us with our goals, and also will contribute to her foundation’s goal of more completely understanding why Alzheimer’s disease disproportionately affects women.

About the Author

Jessica Z.K. Caldwell, PhD, completed her graduate training at the University of Wisconsin, Madison, where she focused on behavioral correlates of function and structure of medial temporal lobe brain regions. She completed an internship at Harvard Medical School and a fellowship at Brown University, where she assessed a wide variety of neuropsychological conditions, including neurodegenerative disease, HIV-related cognitive disorders, head injuries, epilepsy and delirium. Dr. Caldwell is now a staff neuropsychologist at the Lou Ruvo Center for Brain Health.