<p>Altered gray matter volume in patients with herpes zoster and postherpetic neuralgia</p>

Abstract

PurposeThe aim of this study was to measure brain alterations in patients with herpes zoster (HZ) and postherpetic neuralgia (PHN) and compare their differences using a voxel-based morphometry (VBM) technique.Materials and methodsThirty-three patients with HZ, 22 patients with PHN, and 28 well-matched healthy controls (HCs) were recruited. Magnetic resonance imaging data were acquired for all subjects and analyzed using the VBM method. The changes in gray matter volume (GMV) in HZ and PHN groups were compared with those in HC group, and the GMV differences were also compared between the PHN and HZ groups. Further correlation analysis and receiver operating characteristic curves were used to confirm the significance of GMV changes in various brain regions.ResultsCompared with HCs, decreased GMV was found in the bilateral insular lobes and increased GMV was found in the bilateral thalamus in the HZ group. In the PHN group, GMV decreased in the bilateral insula lobes, right middle frontal gyrus, bilateral precentral gyrus, and left postcentral gyrus and increased in the left cerebellar posterior lobe, right parahippocampal gyrus, and right lentiform nucleus. In addition, the PHN group exhibited increased GMV in the left cerebellar tonsil, culmen, and left lentiform nucleus and decreased GMV in the right precentral gyrus compared with the HZ group. Further correlation analysis and receiver operating characteristic curves revalidate the significance of most of these abnormal brain regions.ConclusionThe VBM method revealed widespread GMV abnormalities in HZ and PHN patients. The brains of PHN patients have broader abnormalities in nonpain-related regions, suggesting the complexity of a central mechanism. When PHN patients were compared with HZ patients, the left cerebellar tonsil, culmen, and left lentiform nucleus corresponded to greater area under the curve, suggesting that abnormalities in these regions are risk factors for HZ patients’ transformation to PHN.

The Brain’s Structural Differences in Peripheral Neuropathic Pain: A Comparison Study Between Postherpetic Neuralgia and Lower Back Pain

“…Generally, LBP patients had larger GMV than healthy people in bilateral putamen and left posterior thalamus [38], and in temporal lobes, S1, S2, M1 [45]. On the other hand, PHN patients also showed greater GMV in both thalamus and basal ganglia [12,29], which suggested that these two regions were the main parts involved in pain modulation of both PHN and LBP. That could be the explanation for why both the GBV and MC results of these two areas showed no signi cance in PHN-LBP comparison in our study.…”

“…Compared with function MRI (fMRI) and diffusion tenson imaging (DTI), T1 weighted imaging (T1WI) has the advantages of easier access, higher resolution, and relative insensitivity to artifacts (e.g., head motion, susceptibility). However, few studies [12,29] have explored the GMV changes in PHN from T1WI, let alone MC.…”

Neuropathic pain: Spotlighting anatomy, experimental models, mechanisms, and therapeutic aspects

“…Patients experiencing neuropathic pain do not only show alterations in brain regions associated with sensorimotor functions, but also in regions related to memory, emotion and behaviour. The grey matter volume of patients with postherpetic neuralgia was observed to be increased in the parahippocampal gyrus, whereas decreased in the medial frontal gyrus and the insula lobes (Liu et al., 2019). These findings provide new options for the development of therapies that alternate from conventional pain medication.…”

Pilot Analyses of Interferon Subtype Expression Profiles in Patients with Herpes Zoster or Postherpetic Neuralgia

“…Several pathophysiological mechanistic theories describe PHN as a result of neuronal damage from virus-infected cell lysis, disrupted inflammatory signaling, vasoconstriction with consequent ischemic nerve damage, and increased gray matter volume (16,17). All these concepts, however, in-clude an immunological component.…”