Functional and Structural Changes in Postherpetic Neuralgia Brain Before and Six Months After Pain Relieving

Yi Zhang; Song Cao; Jie Yuan; Ganjun Song; Tian Yu; Xiaoli Liang

doi:10.2147/JPR.S246745

Functional and Structural Changes in Postherpetic Neuralgia Brain Before and Six Months After Pain Relieving

J Pain Res. 2020 May 4:13:909-918. doi: 10.2147/JPR.S246745. eCollection 2020.

Authors

Yi Zhang^{1

2}, Song Cao^{2

3}, Jie Yuan^{2

3}, Ganjun Song^{2

4}, Tian Yu², Xiaoli Liang⁵

Affiliations

¹ Department of Anesthesiology, The Second Affiliated Hospital of Zunyi Medical University, Zunyi 563002, Guizhou, People's Republic of China.
² Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi, People's Republic of China.
³ Department of Pain Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, People's Republic of China.
⁴ Department of Radiology, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou, People's Republic of China.
⁵ Department of Anesthesiology, Zunyi Medical University, Zunyi 563002, Guizhou, People's Republic of China.

Abstract

Objective: Multimodal magnetic resonance imaging (MRI) was used to detect whether 6 months after pain relieving, the structural and functional abnormalities in the brain of postherpetic neuralgia (PHN) patients are changeable.

Methods: Fifteen successfully treated PHN patients were enrolled; the brain activity and structural abnormalities were detected and compared before and 6 months after treatment. The functional parameters were evaluated with resting-state functional MRI technique, i.e., the regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuation (fALFF). Structural changes were detected with voxel-based morphometry (VBM) and diffusion kurtosis imaging (DKI).

Results: Six months after pain relieving, PHN brain showed different ReHo and fALFF values in the frontal lobe, caudate, supramarginal gyrus, anterior cingulate cortex (ACC), cuneus, middle temporal gyrus, and cerebellum. In addition, VBM intensity in the cerebellum increased; DKI values decreased in the thalamus and increased in the temporal lobe after successful treatment.

Conclusion: Six months after pain relieving, functional and structural changes exist in PHN brain. Changes in some differential areas in PHN brain, such as ACC, frontal lobe, thalamus, and temporal lobe indicate that the central plasticity may be reversible after chronic pain relieving.

Keywords: PHN; ReHo; fALFF; fractional amplitude of low-frequency fluctuation; functional magnetic resonance imaging; postherpetic neuralgia; regional homogeneity.