After years of struggling to diagnose Alzheimer’s disease (AD) in its early stages, scientists are finally closing in on several tests that can identify individuals who appear healthy, but are significantly more likely to develop the neurodegenerative disease in the future. Experts believe that AD must be caught early to give potential treatments the best chance of protecting the brain.
The most recent diagnostic breakthrough is a study involving a blood test for AD that was published online Mar. 9, 2014 in the journal Nature Medicine. Researchers recruited a group of 525 healthy individuals aged 70 and older who provided blood samples and underwent cognitive testing once a year over a five-year period. During the study, 28 participants developed mild cognitive impairment (cognitive problems worse than average for a person’s age, but not serious enough to impact daily activities) or AD dementia. When they compared these participants’ blood samples with samples taken from cognitively normal individuals, the researchers found that levels of 10 specific metabolites thought to help promote the health of brain cell membranes were significantly depleted in the 28 participants with cognitive decline. In subsequent trials, the re-searchers demonstrated that these metabolites could be used with up to 96 percent accuracy to predict who was likely to develop AD within the next three years.
“This is a really new and exciting development, but the findings will need to be replicated in a separate sample with a larger number of participants,” comments researcher Rebecca Amariglio, PhD, a neuro-psychologist at MGH, and Instructor in Neurology at Harvard Medical School. “The good news is that this research is one of a number of recent studies looking into diagnostic indicators of AD. Their results are very promising, and suggest that there may be a number of different approaches to identifying the early stages of the disease.
“For example, in addition to this most recent study, scientists have developed a process using PET scans to identify brain deposits of beta-amyloid proteins, which are hallmarks of AD. Other potential diagnostic tools include functional magnetic resonance imaging (fMRI) to observe differences in brain activity that appear to be connected to early AD, and MRI scans to detect atrophy that appears to be linked to the disease process.”
WHAT YOU CAN DO
Worried about memory problems? Here’s where to go for help:
- See a physician for a thorough medical examination to exclude possible causes of memory loss other than dementia.
- Consult a specialist in memory problems, such as a geriatric psychiatrist (MD), neuropsychologist (PhD), geriatrician (MD), or neurologist (MD).
- Enroll in an ongoing memory study at an academic medical center near you.
- Contact professional organizations that provide information and support for people with dementia and AD, such as: the Alzheimer’s Association (225 N Michigan Ave, Fl. 17, Chicago, IL 60601 Tel: 1-800-272-3900, www.alz.org/); the Alzheimer’s Foundation of America (322 8th Ave., 7th Fl., New York, NY 1001, Tel: 1-866-232-8484, www.alzfnd.org); or the National Institute on Aging’s Alzheimer’s Disease Education and Referral (ADEAR) Center (PO Box 8250 Silver Spring, MD 20907, Tel: 1-800-438-4380, www.nia.nih.gov/Alzheimer
Dr. Amariglio’s own research attests to the importance of more subjective indicators of early AD—an individual’s self-reported cognitive concerns. In a study presented at the 2013 Alzheimer’s Association International Conference, Dr Amariglio described an investigation involving 189 healthy adults over age 65 who were questioned about their memory concerns. The partici-pants also underwent PET scans revealing levels of beta-amyloid proteins in their brains. The results revealed that those participants with the greatest accumulation of beta-amyloid were also more likely to complain of problems with higher-level cognitive tasks, such as prioritizing and organizing, leading the research team to conclude that subjective concerns may be an early indicator of AD.
“Now we can combine subjective complaints with biomarkers to help confirm whether an individual has early AD, and institute lifestyle changes and perhaps eventually medications to try to slow that process or ease symptoms,” Dr. Amarigilio says. “Earlier diagnosis will also help us find treatments to halt the progress of AD before it damages the brain.”
Not all cognitive changes noticed by older adults are associated with AD pathology, Dr. Amariglio stresses. Many may be associated with normal aging. Medical challenges, medications, stress, depression, poor sleep, and chronic pain may also interfere with optimal cognitive functioning.
Studies suggest that the speed at which the brain processes information and the ability to ignore irrelevant information and distractions naturally diminish with age. Older adults may have greater difficulty multitasking and performing tasks that require multiple actions. They may have greater difficulties with forgetting names, misplacing objects, remembering the source of information, absorbing information, learning new things, and retrieving stored information. These cognitive challenges can cause stress, which in turn may increase memory and thinking problems in older adults.
“Age-related cognitive changes are normal and are not a cause for worry,” Dr. Amariglio says. “They can usually be addressed using basic memory strategies and working to improve focus and organization.
“On the other hand, some subjective cognitive complaints may indicate something more serious, even when people are able to function normally in everyday life. These complaints represent a change in memory functioning and involve more extensive memory problems. They tend to be consistent, get worse over time, and increase the difficulty of pursuing normal activities. For example, it may become more difficult for individuals to retrace their steps, or they may begin to have significant word-finding problems.”
More serious lapses
“Generally speaking, the more changes an individual observes across a range of different tasks, the greater the likelihood that these may be beyond normal aging,” Dr. Amariglio says.
The following warning signs may be a symptom of more serious memory problems that require further assessment. Check with your medical care provider if you:
- Struggle to remember recent events, but can easily recall things that occurred in the past
- Find it hard to follow conversations or programs on television
- Forget the names of friends or everyday objects
- Cannot recall things you have heard, seen, or read
- Find it difficult to make decisions
- Notice that you repeat yourself or lose the thread of what you are saying
- Have problems thinking and reasoning
- Get lost in familiar surroundings
- Feel anxious, depressed or angry about your forgetfulness
- Find that other people comment on your forgetfulness.MMM
Leave a Reply