In my last post I reviewed a reinterpretation of my neuropsych tests, that, in contrast to the official NIH interpretation, indicates definite impairment. The essential logic was that the NIH report analyzed the results of each of the many separate test items in isolation rather than in relationship to one another. While almost all of the individual tests were within normal limits, the new interpretation by my neuropsychologist friend, Carol, was that the relationships among the tests indicated impairment.
Carol also said that there were subgroups of people who seemed to do significantly better on tests (even when compared to academic peers) than in daily life. Doctors, she said, are often in that group. Apparently, it’s a combination of an ability to concentrate better than others with a similar IQ and having developed test-taking abilities, ie strategies that enabled better test scores than people who didn’t strategize.
I don’t know whether or not I belong to this subgroup, of course. But it would help explain why almost all my individual tests were normal. Aware of the importance of the test, I remember concentrating intentionally and intensely on each item. I wanted to make sure there were no careless mistakes. Even as I took the test, I was surprised by how well it seemed to me I was doing.
I’m also aware of specific strategies I’ve developed, mostly based on having taken the previous tests, which have had some of the same items as in the NIH test. One item, for instance, required me to come up with as many words beginning with a certain letter, say “f,” within the space of a minute. I’d done poorly on this item in previous testing, so, as I ruminated about my poor showing afterwards, I found myself repeating the test mentally using different initial letters. I discovered that once the initial rush of words beginning with, say, “f,” slowed, I could add a second letter, say “r” and began thinking of words that began with “fr,” which brought a second rush of words to mind. Once that slowed, I changed the second letter again and so on. It made a huge difference. Another test item asked me to remember a series of unrelated words or numbers. This time, I concentrated deeply and repeated under my breath the words or numbers several times as each new word or number was given to me, thus creating an inner “aural memory” that significantly augmented my ability to remember.
So there are good reasons to consider the possibility that the cognitive exam interpreted previously as normal does, in fact, show evidence of impairment.
This new interpretation helps me understand why my own perception of my cognitive abilities is so much more dramatic than it is to most others. I do generally function normally, but at a lower level than before. This is called “subjective cognitive decline” (ie the perception of impairment in the face of normal objective testing). And perhaps the word “decline” is better than “impairment.” Mostly I’m not impaired in a way that others would notice, but I know I’ve declined.
Perhaps the most important result that came out of the retesting was that Carol noticed something I’d overlooked in the background of the NIH narrative summary. Commenting on the reports from last summer’s MRI, the report stated that “the recent brain MRI was read as showing generalized cerebral volume loss and small vessel occlusive disease.”
I was shocked, actually! These findings are consistent with vascular cognitive decline, ie impairment due to the obstruction of tiny arteries in the brain, sometimes called “mini-strokes” or “multi-infarct” disease. I had been under the distinct impression that both MRIs during the past year had been normal.
Even after my brain scans indicating no evidence for Alzheimer’s, I never seriously considered vascular impairment; I thought it had been ruled it out. (Several correspondents on this blog and in personal emails, however, suggested the possibility.)
I’ll write on vascular impairment next time.