Non-fluent progressive aphasia: cerebral metabolic patterns and brain reserve.

Functional imaging studies suggest that brain reserve allows patients with Alzheimer's disease with more years of schooling to cope better with brain damage. No studies exist on patients with non-fluent progressive aphasia (NFPA). We aimed to explore metabolic patterns of patients with NFPA and to provide evidence for brain reserve in NFPA. 11 right-handed patients with NFPA and 16 age-matched controls underwent (18)F-FDG PET imaging. Scans of patients and controls were compared in SPM2. A linear regression analysis with glucose metabolism as dependent variable and years of schooling as the independent variable, adjusted for age, gender, and a total score of the CERAD neuropsychological battery was conducted. The NFPA group showed a hypometabolism of the left hemisphere including the middle frontal, and inferior temporal and angular gyri, and the bilateral caudate nuclei and thalami (p(corr)<0.05). The regression analysis revealed a significant inverse association between education and glucose metabolism in the left inferior temporal, parahippocampal, and supramarginal gyri (p(corr)<0.05). We conclude that brain reserve is also present in NFPA.