Trait-anxiety and glial-related neuroinflammation of the amygdala and its associated regions in Alzheimer's disease: A significant correlation.

Background: Positron emission tomography, which assesses the binding of translocator protein radiotracers, ¹¹ C-DPA-713, may be a sensitive method for determining glial-mediated neuroinflammation levels. This study investigated the relationship between regional ¹¹ C-DPA713 binding potential (BP _ND ) and anxiety in patients with Alzheimer's disease (AD) continuum.
Methods: Nineteen patients with AD continuum determined to be amyloid-/p-tau 181-positive via cerebrospinal fluid analysis were included in this cross-sectional study (mild cognitive impairment [MCI, n = 5] and AD [n = 14]). Anxiety was evaluated using the State-Trait Anxiety Inventory (STAI). A whole-brain voxel-based analysis was performed to examine the relationship between ¹¹ C-DPA-713-BP _ND values at each voxel and the STAI score. Stepwise multiple regression analysis was performed to determine the predictors of STAI scores using independent variables, including ¹¹ C-DPA-713-BP _ND values within significant clusters. ¹¹ C-DPA-713-BP _ND values were compared between patients with AD continuum with low-to-moderate and high STAI scores.
Results: Voxel-based analysis revealed a positive correlation between trait anxiety severity and ¹¹ C-DPA713-BP _ND values in the centromedial amygdala and the left inferior occipital area [ P  < 0.001 (uncorrected) at the voxel-level]. ¹¹ C-DPA713-BP _ND values in these regions were a strong predictor of the STAI trait anxiety score. Specifically, patients with AD continuum and high trait anxiety had increased ¹¹ C-DPA713-BP _ND values in these regions.
Conclusions: The amygdala-occipital lobe circuit influences the control of emotional generation, and disruption of this network by AD pathology-induced inflammation may contribute to the expression of anxiety. Our findings suggest that suppression of inflammation can help effectively treat anxiety by attenuating damage to the amygdala and its associated areas.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2024 Published by Elsevier Inc.)