People who have Down syndrome might develop Alzheimer’s disease at a younger age than people without Down syndrome. Recently, however, research showed that some people with Down syndrome might not develop dementia at all. Doctors and researchers are trying to learn why some people with Down syndrome develop dementia, either earlier or later, and others don’t.
Only a few of the approved drug treatments for Alzheimer’s disease have been tested to see whether they work for people with Down syndrome, and these treatments offer few benefits. It’s crucial, then, for us to learn more about normal aging and Alzheimer’s disease in people with Down syndrome.
The University of Kentucky has received funding from the National Institutes of health since 2009 to follow a group of volunteers with Down syndrome. We’ve learned about several important changes that happen in the brain as people with Down syndrome age:
1. We’ve learned that connections in the brain called white matter tracts — like the “wires” connecting various parts in our brains — might be different in people with Down syndrome. The frontal lobe, which is important to our personality, memory and actions, appears to be less strongly connected to other parts of the brain in people with Down syndrome. As these individuals get older, these connections become progressively weaker, possibly leading to personality changes and memory problems.
2. We’re learning that there might be changes in some blood proteins that indicate the need for different Alzheimer’s treatments for people with Down syndrome than for people without the condition. Some of these changes include higher levels of a protein called beta amyloid, which increases with age and might suddenly change as someone develops dementia. Other proteins include those involved with the immune system and inflammation, which appear to be higher in people with Down syndrome as they get older.
3. We’ve learned about which kinds of learning and memory tests are helpful for diagnosing Alzheimer’s disease and which are not. This understanding will help us determine which tests are most helpful in clinical trials that seek to determine whether a treatment leads to improvements in learning and memory for people with Down syndrome.
Our work to understand Down syndrome and Alzheimer’s disease continues.
Participation involves an annual visit including blood measures for wellness, neurologic examinations, tests of learning and memory, changes in walking, and brain imaging. More information is available at www.uky.edu/DSAging.
Elizabeth Head and Frederick Schmitt are the principal investigators for the Aging and Down Syndrome Research Study at the University of Kentucky.