Altered functional connectivity of nucleus accumbens in patients with persistent postural-perceptual dizziness: a resting-state functional magnetic resonance imaging study

Abstract

Objective This study aimed to investigate alterations in functional connectivity (FC) of the nucleus accumbens (NAc) in patients with persistent postural-perceptual dizziness (PPPD) using resting-state functional magnetic resonance imaging (rs-fMRI), and to examine the relationship between aberrant FC and clinical characteristics. Methods Twenty-four patients with PPPD and 25 age and gender matched healthy controls (HCs) were enrolled. Rs-fMRI data was preprocessed using DPABI. The bilateral NAc were selected as seed regions, and seed-to-voxel FC analysis was performed. FC differences between groups were assessed using two-sample t-tests with age, sex, HAMA, and HAMD scores as covariates (voxel-level FDR-corrected q < 0.05). Correlation analysis was conducted between abnormal FC values and clinical variables. Results Compared with HCs, patients with PPPD exhibited significantly enhanced FC between the right NAc and the left superior occipital gyrus (Occipital_Sup_L; peak MNI: -24, -96, 24; T value = 4.35; voxel-level FDR-corrected q < 0.001), as well as between the right NAc and the right Inferior Frontal Gyrus, Orbital part (Frontal_Inf_Orb_R; peak MNI: 39, 45, -3; T value = 4.90; voxel-level FDR-corrected q < 0.001). No significant FC abnormalities were detected for the left NAc seed. Correlation analysis revealed a significant negative correlation between the FC value of right NAc to left superior occipital gyrus and disease duration in PPPD patients (r = -0.61, FDR-corrected q = 0.03). Conclusion Patients with PPPD exhibit enhanced FC between the right NAc and visual- and emotion-related cortical regions, including the superior occipital gyrus and orbitofrontal cortex. The negative correlation with disease duration suggests that these FC alterations may be most pronounced in the early stages of the disorder. These findings provide new insights into the neural mechanisms of visual dependence and emotional dysregulation in PPPD.