Altered spontaneous neural activity in frontal and visual regions in patients with acrophobia

Acrophobia is a prevalent type of specific phobia, which frequently leads to functional impairments and occupational limitations. However, the neural pathology of acrophobia is still largely unknown.

26 acrophobic patients and 30 healthy controls were enrolled in this study. All participants underwent a resting-state fMRI scan. Severity of symptoms was evaluated using self-report and behavioral measures. The regional homogeneity (ReHo) and seed-based functional connectivity (FC) were then examined.

Compared to controls, acrophobic patients demonstrated higher ReHo in the right fusiform gyrus and lower ReHo in the bilateral superior frontal gyrus. Lower FC of right fusiform gyrus-bilateral caudate, right fusiform gyrus-right parahippocampal gyrus, and left medial superior frontal gyrus-left cuneus was also found in the acrophobia group. Additionally, there were negative correlations between behavior avoidance scores and FC of right fusiform gyrus- right parahippocampal gyrus (r = -0.42, p = 0.04) and between scores of the 7-item generalized anxiety disorder scale and FC of left medial superior frontal gyrus- left cuneus (r = -0.40, p = 0.049) in the acrophobia group.

Owing to the cross-sectional design, it was unclear whether the functional abnormalities found in the acrophobic patients were related to state or trait effects.

Preliminary results indicated that acrophobic patients revealed abnormal brain function in orbitofrontal cortex, medial prefrontal cortex, and visual regions. These abnormalities may be helpful in understanding the possible neurobiological mechanism of acrophobia and may serve as potential intervention and prevention targets.