Alzheimer's Archive

It’s happened to all of us: a hand or leg temporarily “falls asleep,” usually from being in one position for too long. Why does it happen? Are there times when you should be concerned about it?

When people with dementia start exhibiting agitated behaviors, doctors often prescribe medications, but these have risks of serious side effects. A new study found that nondrug interventions were more effective than medications in reducing agitation.

News briefs

We've reported before that heavy drinking is tied to an increased risk for developing dementia. A Harvard-led study published online Sept. 27, 2019, by JAMA Network Open suggests that the risk is even worse if you have mild cognitive impairment (MCI). Researchers analyzed the data of more than 3,000 dementia-free adults (average age 78, some with MCI) who reported their alcohol use and underwent psychological testing for six years. People with MCI who drank heavily (more than 14 drinks per week) had a 72% higher risk for dementia than people who drank less than one drink per week. However, people without MCI who drank moderately (seven to 14 drinks per week) didn't appear to have an increased risk for dementia, and even seemed to have a 37% lower risk for dementia compared with people who consumed less than one drink per week. The bottom line: "Our results suggest that moderation is the healthiest approach if you drink. And if you have mild cognitive impairment, you may want to reconsider drinking alcohol at all," says Dr. Kenneth Mukamal, a study author and researcher with the Harvard T.H. Chan School of Public Health.

Image: franckreporter/Getty Images

Semantic memory is your store of factual knowledge and the meanings of words. It also helps you recall nonverbal concepts and relationships between words and concepts. And while some aspects of memory may decline with age, semantic memory does not.

Half of people who live to 85 will develop Alzheimer’s disease — a disturbing statistic. But research into a family in South America has revealed a gene mutation that appears to afford protection, and may lead to a way to treat or possibly even prevent the disease.

In the journals

A new study found that a simple blood test can detect beta-amyloid protein buildup in a person's brain years before Alzheimer's disease symptoms appear. The results were published online Aug. 1, 2019, by the journal Neurology.

High amounts of beta-amyloid can clump together and form plaques on the brain, which is strongly associated with Alzheimer's disease. Other research has found that amyloid plaques can appear as early as 20 years before the first sign of Alzheimer's symptoms, such as cognitive decline and memory loss.

Can a blood test tell whether or not you have a concussion? It’s not quite that simple. There is a test that indicates the presence of substances released into the blood after a brain injury, but for now it is more useful for identifying situations when a CT scan is not necessary.

But some experts say limitations of the study raise questions about the results.

Could one of your regular pills raise your risk of dementia? A study published online June 24 by JAMA Internal Medicine found that people over age 55 who took a daily dose of certain common drugs for approximately three years had a 50% higher risk of developing dementia.

The medicines in question are in a category known as anticholinergics, which are used to treat conditions as diverse as depression, urinary incontinence, allergies, and Parkinson's disease. The study's authors say the findings should prompt doctors to use caution or potentially even avoid prescribing certain medications to people over age 45 on a long-term basis if there are other options available.

Clinical trials for drugs to stop or slow the progression of dementia have not been successful. A recent study attempted to determine how much influence, if any, genetic and lifestyle factors may have on the development of dementia.

In the journals

Gingivitis (gum disease) has been linked to a higher risk of heart disease, but a recent study says that the bacteria that cause gingivitis also may be connected to Alzheimer's disease. The study was published Jan. 23, 2019, in Science Advances.

Scientists have previously found that this species of bacteria, called Porphyromonas gingivalis, can move from the mouth to the brain. Once in the brain, the bacteria release enzymes called gingipains that can destroy nerve cells, which in turn can lead to memory loss and eventually Alzheimer's.