Archive for the ‘memory loss’ Category

Thanks for the Memory: part 2: Dementias

Tuesday, June 19th, 2012

It's on the tip of my tongue

In 1990 I needed neurosurgery. The mass which was removed turned out to be benign, but I had a major post-op bleed and was left with a considerable scar on my right frontal cortex. Up to that point I'd had, as I often said, "the fourth best memory in the family."

Afterwards my brain worked well enough. But I had considerable problems moving information from short-term to long-term memory. So when I bought the Harvard Medical School booklet mentioned in my last post, I was intrigued by the research that has been done on the subject and how it applied to me and to others, especially as we age.

Most of us worry about dementia; the Aging, Demographics and Memory Study figures, published in 2007 looking at people 71 or older, estimated there were 3.9 million people with dementia in the US in 2002. Of that group, 2.4 million had Alzheimer's disease. The crucial factor, I thought, was the prevalence, the total number living with a disease, went up with age from 5% of people in the 71 to 79 year old group to 37.4% in those 90 and above. And there are lots more of us living to that age than before.

It's become clear that having a stroke, what used to be termed a "cerebrovascular accident" (CVA), is another major route for developing dementia. A 2010 study in the journal Stroke describes dementia associated with "first-ever stroke" in a French city of 150,000 inhabitants over a 24-year period. Out of nearly 4,000 patents suffering a CVA, 20.4% had dementia. Risk factors for the outcome included age, diabetes, prior heart attack, and atrial fibrillation (an irregular heart rhythm associated with a risk of emboli, blood clots that can be dislodged, travel to the brain and clog an artery).

These figures clearly included those with new-onset dementia, but, because of the study's design, didn't exclude those who may have had the problem prior to their stroke. Nonetheless a history of stroke nearly doubles the prevalence of dementia in people over 65.

Another group with an increased incidence of neurocognitive (thinking/memory) issues includes the roughly 40 million infected with HIV. At least 30% of that group have associated brain function impairment ranging from minor or mild symptoms to full-fledged dementia. With the newer anti-retroviral drug treatments, the incidence (new cases) of HIV-associated dementia (HAD) has markedly decreased, although with people living longer with the virus, overall there are more HAD patients.

There is a roadblock between the circulation and the brain itself, the blood-brain barrier (BBB), which serves, in usual circumstances, to prevent microbes from invading the central nervous system. The human immunodeficiency virus can penetrate the BBB in several ways: one of which is by hitching a ride inside one kind of immune cells called monocytes. This is termed a "Trojan Horse" method.

Another disease, affecting 1.3 million Americans, is termed Lewy Body Dementia (LBD). It's closely associated with the dementia seen in Parkinson's disease. Both have deposits of an abnormal protein that causes difficulties in brain function. In LBD these proteins are found in several areas of the brain; with Parkinson's they are more localized.

Let's get the right pill to help, not hinder

So why is it important to know what kind of dementia a person has?

Some types respond poorly to medications that may help other forms, at least to a limited extent. And LBD patients may be helped by meds that offer less benefit to Alzheimer patients.

It's not always easy, but an experienced neurologist can often sort out which person has which disease.


Thanks for the Memory: Part one

Thursday, June 14th, 2012

keep in touch with your older friends

My wife and I recently talked about the consequences of aging, physical and mental, and I decided to order a booklet from Harvard Medical School titled "Improving Memory: Understanding age-related memory loss." Then we set out on a Monday through Friday visit to old friends (literally, since most were more than 85 years old and at least five were over ninety). We flew from Denver to a city we once lived in and saw ten individuals/couples over the ensuing four days.

I remembered a family occasion fourteen years ago when my Dad and another elderly relative were talking about whether they'd rather be as they were, over ninety and suffering various aches and pains, but mentally sharp, or like another senior at the dinner was, a year or so older and healthy physically, but over the Alzheimer's cliff. They both voted for being creaky, but lucid.

The older friends we visited in three locales on the recent trip reminded me of Dad's discussion back in 1998. Most were a little frail and complained of a variety of back, leg and joint issues, but they were mentally right on target. On the other hand, I wondered if several had at least mild cognitive impairment.

Then we came home and I started reading the booklet. There are seven normal types of memory problems: a tendency to forget thing over time (transience), absentmindedness, blocking, misattribution, suggestibility, bias, and persistence. All of these can be worsened with age  without implying more severe brain issues: Alzheimer's, other dementias or even mild cognitive impairment.

The missing letters may not mean Alzheimers

I had the second of those seven problems yesterday, seeing a new member of my men's book group on the front steps of the house we were meeting in, introducing ourselves by first names and then sitting through a detailed discussion of a book, The Inventor's Dilemna, over the next two hours.

One of the seniors we visited on our trip had always been superb with names and even in her mid-80s is much better than most of us. I never had that talent and, of course, I have even less of it at age 71.

I had made no real attempt to store the other guy's name, didn't give him one of my usual memory-hook mental pictures, and totally forgot it by the time we left. One trick to overcome absentmindedness is using cues. I'm a "visual-verbal" person, and so I tend to superimpose an unusual tie or a mustache or something similar and then repeat  the cue to myself. When I do that, I remember names. In his case, I hadn't done so.

The book from Harvard has ten ways to promote memory health. One was very striking to me: "Get a good night's sleep." I sometimes read late into the night, 11:30 or 12 or even 12:30, and when I do I'm a tad groggy in the morning. That's not something I should do if I want to be at my best the next day.

So, having been in their company for a few minutes to several hours at most, I wouldn't even venture a guess as to whether the older friends we had eaten a meal with, or talked with for five or ten minutes, were mentally totally normal for their age and encountering one of the seven types of age-related memory problems we'll all have to cope with, or, possibly, had more severe issues.

But I will use the ideas in the book from Harvard Medical School.