Altered EEG Brain Networks in Patients with Acute Peripheral Herpes Zoster

Abstract

Objective: To investigate whether the brain networks changed in patients with acute peripheral herpes zoster (HZ).

Methods: We reviewed the EEG database in Jianyang People's Hospital. Patients with acute HZ (n=71) were enrolled from January 2016 to December 2020. Each included subject underwent a ten-minute and 16-channel EEG examination. Five epochs of 10-second EEG data in resting-state were collected from each HZ patient. Five 10-second resting-state EEG epochs from sex- and age-matched healthy controls (HC, n=71) who reported no history of neurological or psychiatric disorders and visited the hospital for routine physical examinations were collected. Brain network and graph theory analysis based on phase locking value parameter and functional ICA were performed using a self-writing Matlab code and the LORETA KEY tool.

Results: Compared with the HC group, the HZ patients showed significant altered brain networks. The graph theory analysis revealed that the clustering coefficient and local efficiency of full band in HZ patients were lower than those in HC group (P<0.05). In beta band, the global efficiency and local efficiency of HZ patients group decreased, compared with healthy group (P<0.05). The functional ICA showed that three components showed significant differences between the two groups. In component 2, HZ patients showed excess superior frontal gyrus (BA10) neuro oscillation in delta band and less medial frontal gyrus (BA 11) neuro oscillation in beta and gamma bands than that in HCs. And for component 3, the alpha band of the HZ patients presented increased neuro activities in superior frontal gyrus (BA 11) and decreased neuro activities in occipital lobe (BA 18). In component 4, the inferior frontal gyrus (BA 47) showed excess activity in the left hemisphere and reduced activity in the right hemisphere in delta band, compared with HC group.

Conclusion: Altered brain networks exist in resting-state EEG data of patients with acute HZ. The changes of EEG brain networks in HZ patients are characterized by decreased global efficiency and local efficiency in beta band. Moreover, the spontaneous oscillation of some brain regions involving pain management and the connectivity of default mode network changed in HZ patients. Our study provided novel understanding of HZ from an electrophysiological view, and led to converging evidence for treatment of HZ with neural regulation in future.

Keywords: brain network; graph theory analysis; herpes zoster; independent component analysis; phase locking value.

Figure 1

Comparisons of PLV network and graph theory properties between HZ and HC patients*. PLV network connectivity in beta band (13–30 Hz) (A); Comparison of network properties in full band (1–45 Hz) (B) and beta band (13–30 Hz) (C). The blue line in A indicates that the connections between bilateral anterior temporal, right anterior temporal, and right central regions in HZ patients decreased when compared with HCs in beta band. No significantly different connection survival was found in other frequency bands after FDR corrections between the two groups. For B and C, the tail on each bar indicates the corresponding standard error of the mean (SEM). For other frequency bands, no significant differences were found between the two groups (not shown in the figure). *All the results were computed using two sample t-test and corrected with FDR method at level P<0.05.

Figure 2

ICA components showing significant differences between herpes zoster patients and healthy controls. Component 2 (A), component 3 (B), and component 4 (C). The images are shown in MNI space. The red color indicates increased neuronal activity and the blue color indicates decreased neuronal activity. The small triangles along the coordinate axes indicated the maximum electric neuronal activity. The corresponding peak coordinates are displayed in the upper part of each band image. The location assignments of each component are shown in Table 2.