Saturday, September 20, 2008

MEDICAL NEWS: New Pathways Between Memory Loss, Alzheimer's

(previously published here at

Mild cognitive impairment (MCI) is a stage between normal aging and Alzheimer's earliest stages. Understanding how it goes from mild thought problems to dementia could be key to figuring out how to prevent Alzheimer's. The following details of some of the latest research can give you an idea of the importance of aiming early.

Understanding Risk Factors

According to a Mayo Clinic report, the MCI rate increases with age and is higher in men, who are almost twice as likely to develop the condition than women. Although previous studies show women at higher risk of dementia and Alzheimer's, women generally outlive men, perhaps surviving long enough for their conditions to progress.

According to Dr. B. Brent Simmons, assistant professor and head of Temple University Hospital's Senior Care Specialists section of geriatrics, the higher rates of heart disease in men might also affect their chances of getting vascular dementia.

This study collected data from 1,786 people aged 70 to 89 and found that after a year, about 3.5 percent of 70- to 79-year-olds and 7.2 percent of 80- to 89-year-olds become afflicted with it. Overall, the growth rate of new MCI cases in the elderly population is at 5 percent per year - higher than anticipated.

Drug Development

In research by New York's Mt. Sinai School of Medicine, the brains of 124 diabetics taking medication (insulin and other glucose-lowering drugs) had up to 80 percent less beta-amyloid plaque compared to other diabetics and 124 non-diabetics. Beta-amyloid protein clumps in and around the brain, forming plaque that inhibits and destroys neurons necessary for daily functions and memory.

However, even if a combination of insulin and oral anti-diabetes medications may prevent Alzheimer's-related factors, they cannot be prescribed for non-diabetics. Hopefully, though, brain pathways such as insulin signaling could be used in developing new treatment methods.

Besides plaque, Alzheimer's indicators include unusual changes to a protein called tau. A yearlong trial at Duke University Medical Center tested a promising new drug - a nasal spray called AL-108 - on 144 patients with MCI, between ages 55 and 85, and saw a 62.4 percent improvement in memory ability.

Patients took several tests that measured memory ability before and after medication. The tests measured short-term visual, verbal and auditory working memory, functions that deteriorate throughout the progression of Alzheimer's.

Although this drug doesn't cure Alzheimer's, it showed that attacking the protein tangles does work, stabilizing some of the progress of dementia.

Getting It Before It Starts

Instead of just treating symptoms, researchers at the University of Pennsylvania School of Medicine are trying to stop it before it starts, by finding chemical and biological markers of these conditions.

Since Alzheimer's is a disease measured by analyzing symptoms, the goal of the first investigation was, according to its lead researcher, Dr. Leslie Shaw, "to determine if we could detect Alzheimer's disease pathology before a patient went on to have full blown dementia and memory disorders."

The research focused on measuring levels of cerebral spinal fluid (CSF) and establishing benchmark concentration levels of biological indicators for normal, mildly cognitively impaired, and Alzheimer's individuals.

The differences between the baseline levels of three Alzheimer's-associated proteins were significant enough to speed up drug development efforts of biological compounds that can fix these differences.

The second Penn study uses MRI scans to detect abnormal structural changes linked to MCI in the brains of healthy elderly. Radiology professor Christos Davatzikos, Ph.D. and his colleagues monitored these slight physical changes to the brain successfully might provide a way to alert patients and doctors to brain deterioration and memory decline early enough to prepare or begin treatment.

With around 18 percent of 400 patients converting to Alzheimer's a year, this study is ongoing, and doctors are able to "study the progression as it's happening ... at a rate large enough to make our tests reliable or not with sufficiently large number of study subjects," said Dr. Shaw, who is also the director of Penn's ADNI Biomarker Core Lab.

Collaboration is key for all involved, and as Dr. Shaw noted, "the earlier we can detect the disease reliably with confidence, the earlier we can institute and monitor treatment such as diet, exercise, adjusted sleep patterns and having a social life, along with doctor visits, to delay and stop the disease."

The MRI-based study used images from the Baltimore Longitudinal Study of Aging (BLSA) and the Alzheimer's Disease Neuroimaging Initiative (ADNI) and was funded by the National Institute on Aging and the Institute for the Study of Aging.

Dr. Shaw's research was funded by the Alzheimer's Disease Neuroimaging Initiative via the National Institutes of Health.

Heather J. Chin can be reached at

©The Evening Bulletin 2008

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