Posted by Steve Giddings on April 30, 2001 at 20:17:19:
In Reply to: MEMORY posted by JACK DRUM on April 30, 2001 at 20:12:14:
I read the primary article quite closely, as well as the accompanying editorial. My guess is that numbers for this observation will temper somewhat with time, similar to the initial "50% success rate" for catheter- based RFA for trigger points causing atrial fibrillation published in the same august journal now about 3 years ago. Most other studies find their measured incidence to be about 10%, not the 54% at 5 years noted in this study.
Some points:
There was no control group. The authors compared the change in the changes seen in patients who had not undergone any sort of surgery or had any stressful life event.
There was no correlation with the period of time on bypass. One might think that the chance for damage would increase with time of relative O2 deprivation. I don't buy the explananation that the effect was due to subclinical infarcts caused by instrumentation when there were no discrete neurologic deficits.
The results are not consistent with observations made by others.
The results were based on one preoperative evaluation. If this were artifactually increased, or altered by observer bias. The person performing the test may have been biased as to the potential outcome. This is not to imply that the authors "cheated". It is a known effect and the specific reason for blinding clinical trials and doing concurrent controls.
The study was done at one site. The observations made with this population may not be generalizable.
Now, there was something else I was going to say but is has slipped my mind completely (had the maze Jan, 1999...at age 52).
Personally, I had some difficult with viseo-spacial orientation in three dimensions for the first several days (couldn't orient a deck of cards to shuffle them)post op and also had some trouble finding single words that describe complex concepts, particular mechanisms for drugs, word analogies, etc. I was so worried about this that I took several on-line IQ tests and got within 5 points that I got at age 12. The biggest real brain problem I had post op was insomnia, which persists.