Snowden et al. performed a study of how different lifestyle choices such as getting a college education or maintaining a high level of mental activity throughout life can affect cognitive function as a person ages on a group of nuns in "The Nun Study". They collected data regarding lifestyle choices, monitored the changes in the nuns' cognition function as they aged, and performed autopsies on the nuns' brains after they died.
One of the objectives of "The Nun Study" was to determine the relationship between brain infarction and the clinical expression of Alzheimer disease. To accomplish this objective physical manifestations of brain infarction and Alzheimer disease that were found at autopsy were compared to the results of cognition tests for dementia and Alzheimer's disease performed by the nuns during life. Lacunar and large brain infarcts were used as markers for infarction and senile plaques and neurofibrillary tangles in the neocortex were used markers for Alzheimer's disease. The study found that of those that met the criteria for Alzheimer disease, those that had brain infarcts had lower cognitive function and a higher prevalence of dementia than those that did not exhibit infarcts. Of those that didn't meet the criteria for Alzheimer disease, brain infarcts were only weakly associated with poor cognitive function and dementia. An especially high level of dementia was found in participants that had lacunar infarcts in the basal ganglia, thalamus, or deep white matter of the brain. However, fewer neuropathologic lesions of Alzheimer's disease in these areas appeared to result in dementia in those with lacunar infarcts as compared to those without lacunar infarcts. In all study participants, there was a strong association between atherosclerosis of the circle of Willis and lacunar and large brain infarcts. These findings suggest that cerebrovascular disease may lead to brain infarction that may play an important role in determining the presence and severity of the clinical symptoms of Alzheimer's disease.
Results and more information from "The Nun Study" have been published in "Aging With Grace" by Dr. David Snowden.
Reference:
Snowdon DA, Greiner LH, Mortimer JA, Riley KP, Greiner PA, Markesbery WR.
"Brain infarction and the clinical expression of Alzheimer disease. The Nun Study."
JAMA. 1997 Mar 12;277(10):813-7
Subscribe to:
Post Comments (Atom)
No Nun pun intended, but what an awful combination for cognitive function/dementia, ie, Alzheimer's and brain infarctions.
ReplyDeleteDid "good" lifestyle choices prevent either one of these? Id like to think so.
LR
Yes, choices such as obtaining a college education and maintaining a high level of brain activity throughout life helped to prevent the neurodegeneration seen in Alzheimer's patients. Those that did not do these things were shown to have a greater level of neurodegeneration and have a higher risk for developing Alzheimer's symptoms. I suppose the take home message from part of this study is "use it or lose it" in regards to neurodegeneration. Other positive lifestlye choices such as diet, exercise, and not smoking can help prevent factors that can lead to cerebrovascular disease such as dyslipidemia and sustained hypertension, which can reduce a person's risk of having a stroke.
ReplyDelete