Your brain: Use it or lose it

Patients with advanced education showing early signs of Alzheimer’s disease (AD) were found to be less vulnerable to neural damage associated with the disease, according to a review in the March publication of Neurology.

Michael Ewers, PhD, from the department of radiology at University of California, San Francisco, and colleagues, showed how Alzheimer’s patients with higher education undergoing 18F-FDG PET imaging had lower FDG metabolism in the brain than those with lower levels of education but the same signs of Alzheimer’s pathology.

These findings indicate that education, as a measure of cognitive reserve, may help patients compensate for disease activity and maintain cognitive performance in the beginning stages of Alzheimer’s. The evidence supports prior studies showing associations between higher cognitive reserve and lower FDG uptake in the evaluation of preclinical AD.

“Together the current and previous results suggest that across different clinical stages of AD, subjects with high cognitive reserve can tolerate more FDG-PET hypometabolism to maintain a certain level of cognitive performance when compared to subjects with low cognitive reserve,” wrote Ewers et al.

A total of 52 elderly but cognitively healthy subjects with a mean age of 75 years showing signs of preclinical Alzheimer's disease were recruited from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Patients were screened for their level of education and cognitive ability and underwent 18F-FDG PET to evaluate metabolic changes in the brain associated with neurodegeneration.

Higher education was correlated with lower FDG-PET metabolism in the temporo-parietal areas of the brain. In contrast, cognitively healthy subjects with lower levels of education and cognitive reserve demonstrated hypermetabolism of FDG. The increased metabolism in these areas of the brain was thought necessary to maintain healthy cognition.

“The increased FDG-PET metabolism in preclinical AD with low cognitive reserve can be explained by a selection effect: subjects with low FDG-PET and low education are more likely to show mild cognitive impairment (MCI) or AD dementia than to stay cognitively normal,” explained the authors.