Posting in Healthcare
A test of reaction times in middle age may identify people with rice-sized lesions in the brain that are a precursor to Alzheimer's.
As with genetic tests for Huntington's, Alzheimer's has no cure. How knowing you're at the door of a horrible death is of benefit, I could not say.
But what if you're decades away from it, and what if it might be possible to take some action to prevent it?
That's what David Bunce (right), an Australian currently working at Brunel University in England, claims in a paper at PLoS One describing what he calls a 30-second screening test for the disease that can be conducted on people in their 40s. (Picture from the Australian National University.)
A test of reaction times, he wrote, can identify people who might have rice-sized lesions in that portion of the brain devoted to memory. An inconsistent result is the danger signal, he wrote. Consistently fast or slow times indicate lesions are unlikely to be there.
The efficacy of the test was demonstrated by brain scans of 428 participants, all between 44 and 48, 15% of whom had the lesions.
In his paper Bunce suggested the test can help doctors prescribe lifestyle changes or drugs that might delay the onset of symptoms until you have time to die from something else.
Before going on, let's be clear. As I wrote last month, many medical studies are wrong, especially in small studies, in hot areas of research, where the researcher's career is wedded to the idea of being right. All true in this case. (Also note, those are indicators something may be wrong, not proof they are wrong.)
But here's the real kicker. Will those "changes" in diet and lifestyle Bunce holds out hope for help?
Another paper delivered this week, in Neurology, indicates cholesterol levels in middle age are actually a poor predictor of risk.
The result contradicts a large study last year indicated a link between high levels of cholesterol in mid-life and later onset of Alzheimer's. Doctors have been looking at cholesterol as a predictor for dementia because the amyloid plaques, indicating the disease is coming on, are composed of similar stuff.
This idea, that heart health and later brain health may be linked, has been controversial since it was first proposed. But it remains comforting, the idea that controlling a single number will keep you alive.
Maybe too simple, it turns out.
Michelle Mielke of Johns Hopkins looked at a 32-year study of Swedish women, almost 10% of whom eventually suffered dementia, and found no link between cholesterol levels in middle age and dementia in old age.
There was, however, a risk associated with rapid decreases in cholesterol levels entering old age, when they were not the result of using statin drugs, Mielke's paper said. The risk of later Alzheimer's was up 17.5% for this group.
So, do you want to take the Bunce test? Especially if we are not certain what you should do about it?
Nov 11, 2010
The key to the test isn't speed, it's consistency. If you are always fast, or always slow, then you "pass." You probably don't need to be examined for those rice-sized precursors of Alzheimer's. But if we have you do the test, say, 10 times, and 2 times you're distracted or more more slowly than normal, that's the danger signal. Me, I'm consistently slow. Tiny thyroid gland.
My mother was out of her head the last 3 days of her life with liver failure. Thank God it was only 3 days; but those three days are permanently branded in my brain. My mother-in-law has dementia from multiple TIAs. X-rays look like buckshot scattered in her brain. Her judgement's shot, and her thought and speech processes are painfully slow and child-like. My father's wife has stage 3-4 Alzheimers's. Misplaces small objects all the time. Forgets what she's looking for even when it's in plain sight. It's really noticeable when she does repeats: asks the same question over and over for several minutes and promptly forgets the answer each time. Alzheimer's is an ugly disease.
Even if you can't prevent Alzheimer's, finding out early would give you time to learn what to expect, prepare your friends and loved ones, write your will and memoirs, and decide on any coping strategies that you want to try before you're too far gone to think of or implement them. I'd much rather do all that while I still have my cognitive abilities than try to deal with it while already suffering from symptoms (or leave it all to someone else.)
PS In my family 58 is a baby. For at least three generations the youngest person to die was 83. The oldest was 107. Many in their 90's. No history of cancer. If one of my relatives committed suicide at 58 I would be devatated. Once you are in your 80's you may need a little help getting around. We are happy to provide it. The wit and wisdom we get from the truly old are beyond compare. I would feel like I was robbing my kids and great grandkids and all those in the middle if I took myself away from them before my time. And I am betting the writer of post number two would rather have Mom back again.
I have consistantly fast reaction times. I was able to win all the bar tests: catch a falling dollar bill, you name it, I won it. Still can outperform the kids. Nothing to do with brain power, everything to do with a big thyroid gland. I never sleep according to my family, I am always "busy" or doing two things at once. Nothing to do with outsized virtue. Just a really fast thyroid. How would that test work on those like myself? It wouldn't.
Kill yourself too soon, lose a lot of good years. Wait too long, lose the choice. My mom chose not to wait, and did an old fashioned 'Shotgun in the mouth" at 58. We'll never know if she was going to have an O.K. slow fall off or something catastrophic. I miss her, the old bat, but she died like she lived, making her own choices and living (or dying) with the consequences.
The prescription to ward off any of the diseases of aging is always the same. Proper diet (lots of fruits and vegetables), adequate sleep and appropriate exercise, and no test will excuse you of this responsibility to yourself.