Dysfunction of anterior insula in the non- affected hemisphere in patients with post- stroke depression: A resting-state fMRI study

BACKGROUND Post-stroke depression (PSD) is a consequential neuropsychiatric sequela that occurs after stroke. However, the pathophysiology of PSD are not well understood yet. OBJECTIVE To explore alterations in functional connectivity (FC) between anterior insula and fronto-cortical and other subcortical regions in the non-affected hemisphere in patients with PSD compared to without PSD and healthy control. METHODS Resting-state FC was estimated between the anterior insula and cortical and subcortical brain regions in the non-affected hemisphere in 13 patients with PSD, 12 patients without PSD, and 13 healthy controls. The severity of depressive mood was measured by the Beck Depression Inventory (BDI)-II. RESULTS Patients with PSD showed significant differences in FC scores between the anterior insula and the superior frontal, middle frontal, and orbitofrontal gyrus in the non-affected hemisphere than healthy control or patients without PSD (P< 0.05). In post-hoc, patients with PSD showed higher FC scores between the anterior insula and the superior frontal region than patients without PSD (P< 0.05). Furthermore, alterations in FC of the superior frontal, middle frontal, and orbitofrontal gyrus were positively correlated with depression severity, as measured with the BDI-II (P< 0.001).