FDG-PET in the Evaluation of Brain Metabolic Changes Induced by Cognitive Stimulation in aMCI Subjects

Cognitive training has reported to improve cognitive performance in Mild Cognitive Impairment (MCI) as well as in older healthy subjects. 18F-FDG-PET is widely used in the diagnoses of dementia for its ability to identify early metabolic changes. This study was aimed to assess the effect of cognitive stimulation on brain metabolic network and clinical cognitive performance. Thirty aMCI subjects were enrolled in the study and allocated in two groups matched for cognitive profile, sex and schooling and then randomly assigned to the training arm or to the placebo arm. All subjects underwent neuropsychological assessment and PET imaging before and after intervention. We found significant association between brain metabolism and cognitive stimulation in treated aMCI subjects. Brain metabolic changes included Brodmann areas reported to be involved in working memory and attentive processes as well as executive functions. Our study shows that metabolic changes occur earlier than possible clinical changes related to the intervention. 18F-FDG-PET could provide a useful biomarker of response to identify a population of aMCI suitable to respond to treatment, according to most recent data on default network mode and its adaptivity to external stimuli.