Background: The Frontal Assessment Battery (FAB) is widely used to assess executive dysfunction in patients with amnestic mild cognitive impairments due to Alzheimer's disease (aMCI-AD), but its neurobiological meaning is unclear. To elucidate this, we examined the relationship between the FAB score and three key imaging biomarkers: gray matter volume, amyloid-beta (Aβ) deposition, and glucose metabolism.
Methods: Twenty Aβ- and tau-positive aMCI-AD patients and age-matched controls underwent structural magnetic resonance imaging and positron emission tomography with [11C]PiB and [18F]FDG. Voxel-based morphometry and statistical parametric mapping analyses were performed to elucidate the relationships between FAB scores and regional gray matter volume, [11C]PiB uptake for Aβ deposition, and [18F]FDG uptake for glucose metabolism.
Results: FAB scores were significantly lower in aMCI-AD than in controls (p < 0.001). In aMCI-AD, FAB was significantly correlated with right inferior frontal gray matter volume and right medial and left middle frontal glucose metabolism (family-wise error p < 0.05). However, there was no correlation between Aβ deposition and FAB (family-wise error p < 0.05).
Conclusions: The decreased FAB score is linked more with frontal-lobe neurodegeneration than with Aβ pathology in aMCI-AD. The FAB could be an early marker for neurodegeneration related to frontal-lobe executive dysfunction.
Keywords: Alzheimer's disease (AD); Amnestic mild cognitive impairments (aMCI); Frontal Assessment Battery (FAB); Voxel-based morphometry (VBM); [(11)C]PiB; [(18)F]FDG.
Copyright © 2024 Elsevier B.V. All rights reserved.