Acute Herpes Zoster Can Alter Brain Networks, Effecting Pain Perception

According to a study published in the Journal of Pain Research, individuals with acute herpes zoster (HZ) have altered brain networks based on resting-state electroencephalography (EEG) data.

The analysis showed that the synchronization of bilateral anterior temporal and right central EEG signals in β-band tended to decrease for individuals with acute HZ. This decrease is important for pain perception and modulation, according to the study

Individuals with acute HZ showed decreases in global and local efficiency, clustering coefficient, and increased shortest path length. This could lead to potential deficits in cognition considering that beta was involved in cognitive functions, according to the study. Investigators suggest that these changes could be used as a biomarker for identification of cognitive functions.

Additionally, individuals with acute HZ showed a reduction of beta and gamma activity in the left middle frontal gyrus (MFG), which could be caused by different natures of pain or detection methods and could show an inhibition response to HZ pain, according to the study.

The superior frontal gyrus (SFG) have also been reported to anticipate types of pain, which had excessive delta and alpha activity, suggesting that the balance between excitation and inhibition has been altered, according to the researchers. The study included 71 patients who were diagnosed with acute HZ from January 2016 to December 2020 in Jianyang People’s Hospital.

Patients were included if they were 20 through 80 years of age and the onset time of acute HZ was less than 14 days; reported no other diseases that might affect EEG patterns; no previous nervous system disease, mental disease, or head trauma; MRI scanning on the brain showed negative intracranial results.

A control group of 71 patients who were deemed healthy were matched with patients with HZ. Ten-minute scalp EEG data were collected for all subjects.

The brain changes were characterized by the decrease clustering coefficient, global efficiency, local efficiency, and increased shortest path length in the beta band. In addition, some of these brain regions involved pain management such as the SFGs and the MFGs.

A limitation of the study was that the population was relatively small. Investigators add that further studies should be conducted to explore the cognitive function evolutions.

Reference

Zhou Y, Liu Z, Sun Y, Zhang H, Ruan J. Altered EEG Brain Networks in Patients with Acute Peripheral Herpes Zoster. J Pain Res. 2021;14:3429-3436 https://doi.org/10.2147/JPR.S329068