Recognizing the signs of Alzheimer's
By the faculty of Harvard Medical School for The Harvard Medical School Adviser

Q: My mother has several relatives with Alzheimer's disease. She's now in her early 70s and becoming more forgetful. How can I tell if she's showing the early signs of the disease?

A: Regardless of age, everyone experiences occasional episodes of forgetfulness. Many people fear that these lapses are a sign of Alzheimer's, the most common form of dementia. But there are important differences between simple forgetfulness and dementia. Experts now recognize a third state called mild cognitive impairment, which falls in between normal memory function and dementia. Although people with mild cognitive impairment face a higher risk of developing dementia, a good number retain enough memory and judgment to get along with little or no outside help.

Normal forgetfulness is neither progressive nor disabling. Normal or mild memory problems are likely to surface when people are under stress, fatigued, ill, distracted or overloaded. They will often remember the forgotten information later. Written reminders and other memory-jogging techniques can help overcome this kind of forgetfulness.

A certain increase in forgetfulness seems to be a normal byproduct of aging and is perhaps a result of changes in the brain that begin around age 50. For example, there is a gradual loss of receptors on brain cells and a decline in certain brain chemicals. Between half and two-thirds of people age 50 or over have some degree of memory loss.

Mild cognitive impairment (MCI) falls between normal forgetfulness and dementia. At least one cognitive (thinking) domain -- usually memory -- is below normal or in decline. When memory is affected, the condition is called amnesic MCI. Although some people with MCI remain stable or even improve, studies show that the many, especially those with amnesic MCI, eventually develop dementia.

Autopsies have shown that the brains of people with amnesic MCI have more clumps and tangles of brain cells than normal people. These physical changes may explain the symptoms of the disease. But these abnormalities aren't as widespread or serious as they are in people with Alzheimer's disease. About 10 percent to 15 percent of people with MCI progress to dementia each year. MCI becomes more common with age and affects 3 percent to 22 percent of people over age 65.

People who have MCI are able to carry on daily activities with little difficulty, but they may show some weaknesses. In particular, they may have subtle problems with language, attention and problem-solving. And special testing may reveal they have a harder time learning and recalling information compared with people who are the same age and have similar education levels.

With dementia, a person's memory loss is severe enough that it interferes with their ability to function socially and at work. People with dementia don't just have memory problems, they also have trouble with abstract thinking, judgment and doing complex physical tasks (such as writing).

Early in the disease, people may lose track of time, and the sense of time becomes more distorted as problems progress. People with dementia may insist it's time to leave immediately after arriving at a place, or they may complain of not having been fed right after they have finished eating.

Changes in mood and personality are often the most convincing evidence that something is wrong. Many people lose interest in their usual activities. And they may become withdrawn, irritable or inexplicably hostile.

Dementia also affects a person's ability to use and understand language. A common symptom is being unable to think of the right words, so the person may try to cover up with long-winded descriptions that fail to reach the point. Or he or she may angrily refuse to discuss the matter further. Substituting a similarsounding word ("wrong" instead of "ring") or a related word ("read" instead of "book") is common.

Other symptoms of dementia include perception problems and behavior changes. For example, a person may believe their spouse is an impostor, become frightened by ordinary sounds or fail to recognize their own reflection in a mirror. Behavior problems include being stubborn, pacing or hand-wringing, wandering, using obscene or abusive language, stealing, hiding things and wandering. Strong emotional responses to minor problems are another symptom.

Scientists are developing imaging techniques and blood and spinal fluid tests that may one day be able to diagnose this dreadful disease in its earliest stages. For now, doctors have to rely on clinical criteria and mental function testing. And we all await the most important progress of all, better ways to prevent and treat Alzheimer's disease and other forms of dementia.

Copyright 2007 the President and Fellows of Harvard College. Developed by Harvard Health Publications (www.health.harvard.edu). Distributed by UFS. Submit q ue harvard_adviser@hms.harv ard.edu.