Altered Functional Connectivity of Amygdala with the Fronto-Limbic-Striatal Circuit in Temporal Lobe Lesion As a Proposed Mechanism for Poststroke Depression

Objective: Poststroke depression (PSD) is an important complication that affects stroke rehabilitation. Abnormal cortical-subcortical connectivity may be associated with the development of PSD. However, few studies have focused on the emotional network of PSD in the temporal lobe lesions. The aim of is study was to investigate amygdala-cortical functional connectivity (FC) in the temporal lobe in individuals with and without PSD.

Design: Twenty-three patients with PSD and 21 stroke patients without depression were recruited to undergo functional magnetic imaging scanning.

Results: In stroke patients with depression, the left amygdala had increased FC with the bilateral precuneus and right orbital frontal lobe but decreased FC with the right putamen. The right amygdala had increased FC with the right temporal pole, right rectus gyrus, and left orbital frontal lobe but decreased FC with the right primary sensory area (S1). Correlative analyses revealed that the amygdala's FCs with the right orbital frontal lobe, right insular cortex, and right cingulate cortex were correlated with the Hamilton Depression Rating Scale score.

Conclusion: The current study identified mood affected through the fronto-limbic-striatal circuit in PSD. Hyperconnectivity between the amygdala, default mode network, and salience network might be related to depressive symptoms, which may provide novel insight into the underlying neuropathologic mechanisms of PSD in temporal lobe lesions.