Longitudinal changes of cerebral glucose metabolism in semantic dementia

Background: Semantic dementia (SD). Objective: To identify the pattern of decline of cerebral glucose metabolism in SD using cerebral F-18-fluoro-2-desoxy-D-glucose positron emission tomography scanning (F-18-FDG-PET). Methods: Eight patients with SD underwent F-18-FDG-PET at baseline and at re-examination in average 15 months later. Results: Compared with healthy control subjects, patients with SD showed a significant asymmetrical ( left 1 right) hypometabolism of the temporal lobes, particularly of the anterior poles, at baseline. At follow-up, we observed a deterioration of cognitive abilities. However, in addition to the temporal lobes no other cortical or subcortical region showed a significant reduction of glucose metabolism except the anterior cingulate cortex ( pcorr < 0.05). Conclusion: Subtle functional changes suffice to produce significant neuropsychological deterioration. Copyright (C) 2006 S. Karger AG, Basel.