A new study suggests that the relationship between brain shrinkage and memory loss in Alzheimer's disease changes across the age spectrum, especially in advanced age.
The research, which appeared in a recent online issue of the medical journal Neurology, found that the pattern of changes associated with Alzheimer's disease appear to be less noticeable in people over the age of 80 (classified as “very old”) compared to those between the ages of 69 and 75 (“young-old”).
Executive function, immediate memory and attention/processing speed were less abnormal in those considered very old when compared to their healthy counterparts in the young-old grouping. The very old also showed less severe thinning of portions of the cerebral cortex and the overall cerebrum than the young-old. This is in part because these brain areas decrease in thickness due to age, so there are fewer differences between the healthy very old brain and the very old brain with Alzheimer's, researchers said.
Researchers studied 105 people with Alzheimer's and 125 people who were free of dementia. Participants were grouped into those who were between the ages of 60 and 75 and those age 80 years and older. All were given tests that measured language, attention and speed of processing information, executive function and immediate and delayed ability to recall information.