# Abnormal intrinsic brain functional network dynamics in patients with postherpetic neuralgia

## TL;DR

This study found altered brain network dynamics in patients with postherpetic neuralgia compared to healthy individuals and those with herpes zoster.

## Contribution

The study reveals novel insights into dynamic brain connectivity and topological changes specific to postherpetic neuralgia patients.

## Key findings

- PHN patients showed decreased proportion in strongly connected brain states and increased in intermediate states.
- PHN patients exhibited altered nodal network metrics in specific brain regions compared to healthy controls.
- Nodal betweenness centrality in the right supramarginal gyrus correlated with disease duration in PHN patients.

## Abstract

This study aimed to investigate the temporal characteristics of the functional connection state patterns and the topological structure of dynamic brain functional networks of patients with postherpetic neuralgia (PHN).

We recruited 23 PHN patients, 45 herpes zoster (HZ) patients and 27 matched healthy controls (HC) to participate in resting-state functional magnetic resonance imaging. We applied the sliding time window analysis method and K-means clustering analysis to identify dynamic functional connectivity (dFC) variability patterns in three groups. The graph-theoretical approach was used to investigate the topological structure of brain functional networks.

All participants showed three types of dynamic functional connection states (state I: strongly connected, state II: sparsely connected, state III: intermediate pattern). Compared to HC, PHN patients exhibited a decreased proportion in state I (p = 0.024, FDR corrected) and increased proportion in state III (p = 0.006, FDR corrected). PHN patients dwelled longer in state III (p = 0.020, FDR corrected). Besides, the dynamic topological properties of PHN patients exhibited significant alterations in nodal network metrics. Compared with HC, PHN patients had an elevated nodal betweenness centrality in the right supramarginal gyrus (p = 0.003, FDR corrected) and a decreased nodal degree centrality in the left transverse temporal gyrus (p = 0.002, FDR corrected) in state I. Furthermore, the nodal betweenness centrality in the right supramarginal gyrus in state I was positively correlated with the disease duration (r = 0.679, p = 0.008).

Dynamic functional connection states and the variance of topological organization may offer new insights into intrinsic functional activities in PHN brain networks.