RESUMO
BACKGROUND: The purpose of this study was to explore the clinical and brain functional abnormalities in patients with mild Alzheimer's Disease (AD) and patients with amnesic Mild Cognitive Impairment (aMCI). METHODS: we used resting spect-neuropsychology correlations method. RESULTS: We found that parieto-temporal associative cortex, mainly involving the inferior parietal lobule, posterior cingulate and middle temporal gyrus, is compromised early in AD. These results suggest that the dysfunction in these areas contributes to cognitive decline in the storage of verbal information, drawing abilities and non-verbal abstract reasoning in AD. The aMCI group showed hypoperfusion primarily involving the frontal areas bilaterally, and this correlated with the impairment in free delayed recall on a verbal memory task. CONCLUSION: Our results underlie the clinical differences between AD and aMCI patients that might reflect the involvement of different degenerative mechanisms in these groups.