Altered Regional Spontaneous Brain Activity and Default Mode Network Functional Connectivity in Herpes Zoster-Related Pain Patients with High Anxiety.

Pain and psychological disorders are two common symptom clusters in patients with herpes zoster-related pain (HZ-RP). We utilized functional magnetic resonance imaging (fMRI) to investigate functional characteristics of the brain in HZ-RP patients with different levels of anxiety. Twenty-five HZ-RP patients with high anxiety (HZ-RP with HA) and 26 HZ-RP patients with low anxiety (HZ-RP with LA) were enrolled. Fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo) and functional connectivity (FC) based on the brain regions with significant differences and default mode network were compared between two groups. Multivariate linear regression models were used to investigate impact of clinical characteristics on significant abnormalities, and moderation analysis was used to examine interaction between pain and anxiety. Compared with HZ-RP with LA, HZ-RP with HA resulted in increased fALFF in the right Rolandic operculum (RO) and ReHo in the left middle temporal gyrus (MTG) but decreased ReHo in the right precentral gyrus (PrCG). The left anterior prefrontal cortex showed decreased FC with the left medial superior frontal gyrus, whereas the left occipital cortex showed increased FC with the right fusiform gyrus, right MTG and left precuneus in HZ-RP with HA. Multivariate linear regression models revealed that the degree of pain and anxiety contributed to explaining the variance in the fALFF of the right RO, and anxiety alone correlated with ReHo abnormalities in the right PrCG. Abnormal brain function, particularly in the right PrCG, may underpin anxiety-related pathophysiology in HZ-RP patients, suggesting potential neural targets for intervention.