Memory lapses are common and increase with age; when do they signal Alzheimer's?

By Rachel Saslow
Washington Post Staff Writer
Tuesday, February 9, 2010; HE01

Where did I park my car?

What is that lady's name?

Where are my glasses?

Some call these "senior moments" or "tip-of-the-tongue" experiences. They're mundane for many elderly (and not-so-elderly) adults, but when do they become something more serious? How does one know when it's time to get screened for a memory disorder?

"The reason it's becoming such an acute concern for everybody is that baby boomers are starting to get into the higher-risk age group, but the bigger driver for this is the baby boomers' parents," says James Lah, an Emory University neurologist, who is 48 and has parents ages 73 and 81. "That age bracket is very high risk, and seeing it in our parents makes you acutely aware and afraid of that prospect."

The risk of mild cognitive disorder and dementia increase with age; Alzheimer's disease is the leading cause of dementia. About 5 million Americans live with Alzheimer's and, in 2008, it passed diabetes to become the sixth-leading cause of death in this country, according to the Centers for Disease Control and Prevention, partially because of the lack of treatments to stop or reverse it. Some studies estimate that a person's risk of developing the disease doubles every five years after age 65.

Memory lapses start in our 20s, though people don't typically notice or fret about them until their 50s. In a study published last year in the journal Neurobiology of Aging, psychologists asked about 2,000 participants to solve puzzles, identify patterns and remember words and details from stories, among other memory tests. The top performers were 22 years old; researchers saw a notable decline in the ability to make rapid comparisons, remember unrelated information and detect relationships by age 27. A weakening memory can usually be detected by around age 37, according to the study. The good news was that people's vocabulary and general knowledge increase until at least age 60.

"Once you hit your 40s and especially your 50s, your memory is not as good as it used to be," says Gary Small, a professor of psychiatry and aging at the University of California at Los Angeles. "The brain science of aging certainly backs that up."

While it's not healthy to over-interpret everyday memory lapses, it's important to bring up with a doctor anything that strikes you or your family as unusual. It's also wise to do this sooner rather than later, because treatments for Alzheimer's, though not completely effective, may provide some help when the disease is diagnosed early. Also, a doctor can screen a patient for other conditions that can cause memory loss, such as stroke, a bad interaction among medications or a thyroid disorder.

More common conditions such as depression, hormonal changes, stress, fatigue and a poor diet can contribute to forgetfulness, so sometimes lifestyle changes can restore memory function. The strongest memory-protective lifestyle strategy is physical exercise, Small says. Just 10 minutes of brisk walking each day can help lower one's Alzheimer's risk, he says. Lah says his male patients uniformly hate his suggestion to take up ballroom dancing, which is more likely to protect against dementia than, say, golf, because it is more physically demanding and requires a more active thought process.

"It's always good for a giggle during an otherwise difficult discussion," he says.

Some people turn to "brain calisthenics" such as crossword puzzles, playing music or learning a new language to stay sharp. A study published last year in the journal Neurology backed up this approach: Scientists found that people who did 11 such activities a week delayed rapid memory loss by about 1.3 years compared with those who did just four a week. Still, both Small and Lah say it's a stretch to claim that any of the brain exercise programs are proven to prevent memory disorders.

Others swear by ginkgo biloba, but a study last year in the Journal of the American Medical Association suggested that the extract does not reduce the chances of dementia. Then there are omega-3 fatty acids -- which Small says some studies suggest may be helpful although "the evidence is not overwhelming" -- and the much-ballyhooed pomegranate juice. The bright-red seeds of the pomegranate have lots of Vitamin C and other antioxidants, which fight the free radicals that can damage brain cells. Studies show an association between ingesting antioxidants and having a lower risk for Alzheimer's, but any claim that drinking pomegranate juice would be beneficial would have to be based on a double-blind, placebo-controlled trial, "which I have not seen," Small says.

"With memory lapses, it's the degree of the problem," he says. "If you forget where you place your keys, that's common. But if you put them in the refrigerator repeatedly, that's a problem."

Starting with Small's example, here are some common "senior moments," juxtaposed with situations that might be more troublesome:

NORMAL: Forgetting your keys.

PROBLEMATIC: Putting your keys in the refrigerator.

Acting as if the keys belong between the milk and the eggs shows a level of confusion that interferes with daily life, a good benchmark for determining if a slip is something more serious. So if you find your car keys in the dairy drawer, is it time to see a neurologist? Not exactly, says Molly V. Wagster, chief of the behavioral and systems neuroscience branch at the National Institute on Aging.

"I can see a cognitively healthy person of any driving age getting distracted, carrying several packages at once and then they get a yogurt out on the way to work and put the keys in the refrigerator," Wagster says.

Multitasking gets more difficult as people age. What's important is that the person realizes something is missing and they keep searching for it until they find it, she says. People with dementia might forget that they need to find the car keys and then forget that they need to go to work.

NORMAL: Forgetting where you parked.

PROBLEMATIC: Forgetting where you parked once a week.

Working memory is a kind of short-term memory that is particularly vulnerable as we age. Our working memory contains information that you hang on to for a short while for a specific purpose, such as where we parked the car. The brain also has to be able to change and update information in the working memory.

"If you park in a parking lot next to a large shopping mall and go in, walk through several stores and exit from a different door, you need to be able to update your working memory because you're exiting at a different orientation," Wagster says. "But once you get to your car, you don't need that information anymore" and can therefore shed it.

While forgetting where you parked once in a while is normal, doing so once a week suggests a faulty working memory, interferes with daily life and could signal a larger problem.

NORMAL: Forgetting a person's name.

PROBLEMATIC: Forgetting a person's name and then repeatedly asking him or her, "What's your name again?"

It's normal for our brains to change over time, just like our muscles, bones and skin show their ages, Lah says.

"Just as you don't run as fast at 70 as 20, likewise those brain cells you've been carrying around for 70 years don't fire and transmit information as quickly as they did when you were 20," he says.

To retrieve information such as a person's name, it has to be stored correctly. That means that when you meet a new person, you have to learn his or her face, name and some identifying details and then consolidate those bits of information. If that system isn't working, retrieval won't be possible.

"Where it becomes much more worrisome for those concerned with Alzheimer's, it's not just the retrieval process that becomes inefficient: The brain cells and networks responsible for learning information become damaged."

Repeating questions is a common symptom of Alzheimer's and could signal a damaged short-term memory.

NORMAL: Inability to program the cable box.

PROBLEMATIC: Forgetting how to turn on the television.

Programming a cable box is something you rarely have to do, and with three remotes and increasingly complicated entertainment systems, it's normal to need some help. But if someone watches television every night and is suddenly befuddled by the buttons on the remote, that could be a problem. People with memory disorders often find it difficult to complete daily tasks that they used to do automatically, such as driving to work, remembering the rules of a favorite game or even bathing.

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