PET Shows Highly Educated Alzheimer’s Patients Cope Better

PET images show that neural reserve and neural compensation allows highly educated patients with prodromal Alzheimer’s disease to cope better with the disease than their less educated peers, according to a study published in The Journal of Nuclear Medicine.

Italian researchers sought to determine if there was a metabolic basis for resilience to the neurodegeneration (cognitive reserve) in patients who were highly educated and were showing signs of mild cognitive impairment that later progressed into Alzheimer’s disease. Patients with more than 12 years of education were considered to be higher educated, and those with fewer than 12 years had lower levels of education. Cognitive reserve refers to the hypothesized capacity of an adult brain to cope with brain damage in order to maintain a relatively preserved functional level.

The highly educated group, comprising 48 controls and 28 prodromal Alzheimer’s disease patients and the poorly educated group, comprising 42 controls and 36 prodromal Alzheimer’s disease patients, underwent 18F-FDG PET scans. Brain metabolism was first compared between education-matched groups of patients and controls. Then the researchers compared the metabolism between highly and poorly educated prodromal Alzheimer’s disease patients in both directions to identify regions of high education-related metabolic depression and compensation.

The researchers found a higher metabolic activity in the dorsolateral prefrontal cortex for the patients with Alzheimer’s disease. More extended and significant correlations of metabolism within the right dorsolateral prefrontal cortex and other brain regions were found with highly educated than less educated patients or even highly educated controls.

The results suggested that neural reserve and neural compensation were activated in the highly educated prodromal Alzheimer’s disease patients.

“This study provides new insight into the functional mechanisms that mediate the cognitive reserve phenomenon in the early stages of Alzheimer’s disease,” lead author Silvia Morbelli, MD, said in a release. “A crucial role of the dorsolateral prefrontal cortex was highlighted by demonstrating that this region is involved in a wide frontotemporal and limbic functional network in patients with Alzheimer’s disease and high education, but not in poorly educated Alzheimer’s disease patients.”

The authors concluded, “The present findings suggest that highly educated prodromal Alzheimer’s disease patients can cope better with the disease thanks to neural reserve but also to the recruitment of compensatory neural networks in which the right dorsolateral prefrontal cortex plays a key role.”