This week Mayo Clinic researchers reported that men are 1.5 times more likely than women to have memory problems. You may wonder, then, how it can also be true (which it is) that more women develop and die from Alzheimer's?
The kind of memory loss in the new study is called mild cognitive impairment (MCI). Scientists theorize that in men, there's a delayed progression from MCI to dementias like Alzheimer's. Or possibly dementia in women progresses faster. Nobody's sure.
What is certain is that memory disorders are plentiful enough to be hard to keep straight. Seems like a good time for a recap:
- Normal memory loss: Everybody's brain ages. As the connections and chemicals in the brain alter with time, many people forget things like names, keys, and what the heck they went in the next room to get. Normal.
- Mild cognitive impairment: Problems with memory, language, or other mental functions are noticeable to others (and show up on tests) but don't interfere with daily life. Dad continually loses his keys and forgets the neighbors' names but he can still pay bills and drive around. The April 18th Psychiatric News reports that 1 in 5 people over 70 have MCI—more than previously thought. Some develop Alzheimer's, some don't.
- Early Alzheimer's: In addition to pronounced memory problems (Mom can't remember what happened yesterday or major news events), there's cognitive trouble—she can't count backward by 7s, messes up planning meals or managing finances, gets lost. It's diagnosed through testing and a complete medical exam to rule out other problems.
- Mid Alzheimer's, Late Alzheimer's: Always follow in progression after early-stage. There are no improvements, only periods of stabilization and gradual decline.
- Early-Onset Alzheimer's: Not to be confused with early-stage Alzheimer's, early-onset starts before age 65. New wrinkle: Researchers now say earlier dementia, before age 45, is almost never Alzheimer's-related.
- Dementia: Not a disease itself, but a set of symptoms including memory loss, cognitive problems, and other effects of deteriorating brain function. Alzheimer's is just one type of dementia. Others include vascular dementia (caused by tiny strokes) and Lewy Body Dementia (of which Parkinson's Disease Dementia is a subset).
- Senile dementia: An outdated term that usually referred to what we now call Alzheimer's.
- Other causes of memory loss: Depression, stress, insomnia, alcoholism, brain tumors, medication, or many other things can be the culprit. Just this week it was reported that common incontinence drugs can confuse memory in older people.
And once you have all these straight comes an idea to turn them on their heads: Some scientists question whether normal memory loss, MCI, and Alzheimer's are distinct conditions -- or even that Alzheimer's is a single "disease." Peter Whitehouse, an acclaimed neurologist and Alzheimer's expert who wrote The Myth of Alzheimer's (a must-read that came out in January) is one. We just don't know enough about the disease processes to be sure. He prefers a new (and, he says, less stigmatized) term for these degrees of memory impairment: "brain aging."
Just semantics? Or does what we call various brain impairments affect how sufferers are viewed and treated? A question for the 21st century.
Image by Flickr user e3000s, used under the Creative Commons attribution license.