Herpes Zoster and Postherpetic Neuralgia: Practical Consideration for Prevention and Treatment

Peripheral and central pathogenesis of postherpetic neuralgia

BACKGROUND

Postherpetic neuralgia (PHN) is a classic chronic condition with multiple signs of peripheral and central neuropathy. Unfortunately, the pathogenesis of PHN is not well defined, limiting clinical treatment and disease management.

OBJECTIVE

To describe the peripheral and central pathological axes of PHN, including peripheral nerve injury, inflammation induction, central nervous system sensitization, and brain functional and structural network activity.

METHODS

A bibliographic survey was carried out, selecting relevant articles that evaluated the characterization of the pathogenesis of PHN, including peripheral and central pathological axes.

RESULTS

Currently, due to the complexity of the pathophysiological mechanisms of PHN and the incomplete understanding of the exact mechanism of neuralgia.

CONCLUSION

It is essential to conduct in-depth research to clarify the origins of PHN pathogenesis and explore effective and comprehensive therapies for PHN.

Varicella-zoster virus-related neurological complications: From infection to immunomodulatory therapies

The Varicella-zoster virus (VZV), classified as a neurotropic member of the Herpesviridae family, exhibits a characteristic pathogenicity, predominantly inducing varicella, commonly known as chickenpox, during the initial infectious phase, and triggering the reactivation of herpes zoster, more commonly recognized as shingles, following its emergence from a latent state. The pathogenesis of VZV-associated neuroinflammation involves a complex interplay between viral replication within sensory ganglia and immune-mediated responses that contribute to tissue damage and dysfunction. Upon primary infection, VZV gains access to sensory ganglia, establishing latent infection within neurons. During reactivation, the virus can spread along sensory nerves, triggering a cascade of inflammatory mediators, chemokines, and immune cell infiltration in the affected neural tissues. The role of both adaptive and innate immune reactions, including the contributions of T and B cells, macrophages, and dendritic cells, in orchestrating the immune-mediated damage in the central nervous system is elucidated. Furthermore, the aberrant activation of the natural defence mechanism, characterised by the dysregulated production of immunomodulatory proteins and chemokines, has been implicated in the pathogenesis of VZV-induced neurological disorders, such as encephalitis, myelitis, and vasculopathy. The intricate balance between protective and detrimental immune responses in the context of VZV infection emphasises the necessity for an exhaustive comprehension of the immunopathogenic mechanisms propelling neuroinflammatory processes. Despite the availability of vaccines and antiviral therapies, VZV-related neurological complications remain a significant concern, particularly in immunocompromised individuals and the elderly. Elucidating these mechanisms might facilitate the emergence of innovative immunomodulatory strategies and targeted therapies aimed at mitigating VZV-induced neuroinflammatory damage and improving clinical outcomes. This comprehensive understanding enhances our grasp of viral pathogenesis and holds promise for pioneering therapeutic strategies designed to mitigate the neurological ramifications of VZV infections.

Management of Herpes Zoster Infection Using a Combination of Allopathic and Herbal Medication: A Case Report

Herpes zoster (HZ) also known as shingles is the reactivation of varicella-zoster virus (VZV) that causes chickenpox. It usually occurs in adults after remaining dormant in the dorsal root ganglia or ganglia of the cranial nerves for several years. It typically manifests as vesicle crops in a dermatomal or "zosteriform" pattern, which shows vesicle, ulcer, and scab distribution that is unilateral, clustered, and linear in a dermatome that is supplied by a single nerve. Patients usually experience prodromal symptoms of deep, severe aching or burning pain. Medicinal treatment frequently includes antiviral drugs to decrease the severity of the lesion and steroidal drugs to reduce symptoms of inflammation. It is also a known fact that steroid has several adverse effects on patients due to which therapeutic drugs with lesser side effects may be given to patients such as herbal medications. This case presentation reports a patient with HZ viral infection who was successfully treated with a meticulous combination of conventional allopathic drugs with ayurvedic medication with a significant positive response to the medication.

Trigeminal Neuralgia Secondary to Herpes Simplex Virus Type 1 Infection Treated With Oral Acyclovir

Trigeminal neuralgia (TN) is characterized by episodic electric, shock-like facial pain. Though often idiopathic, herpes simplex virus type 1 (HSV-1) reactivation can rarely cause symptomatic TN. We report the case of a 30-year-old woman who developed oral HSV-1 lesions followed by right-sided TN pain. MRI of the brain did not reveal neurovascular compression. TN pain completely resolved with oral acyclovir treatment alone, without anticonvulsants. This highlights the importance of considering atypical etiologies such as HSV-1 reactivation in TN evaluation. Early antiviral therapy may treat underlying inflammation and provide sustained symptom relief in HSV-associated TN.

Recent advances in the treatment and prevention of peripheral neuropathy after multiple myeloma treatment

The incidence of multiple myeloma (MM) is increasing year by year, requiring chemotherapy drugs to control the condition. With the advent of new proteasome inhibitors, immunomodulators, and monoclonal antibodies, the prognosis of patients has improved significantly. However, peripheral neuropathy caused by drugs limits the dose and duration of treatment, which seriously affects patients' quality of life and treatment outcome. Although the neuropathies induced by chemotherapy drugs have attracted much attention, their mechanism and effective prevention and treatment measures are not clear. Therefore, how to alleviate peripheral neuropathy caused by drugs for treatment of MM is a key issue in improving patients' quality of life and prolonging their survival time, which have some clinical value. In this paper, we review the current research on the pathogenesis, pharmacological and nonpharmacological treatment, and prevention, which expects to present instruction for peripheral neuropathy after treatment of MM.

Therapeutic Strategies for Postherpetic Neuralgia: Mechanisms, Treatments, and Perspectives

PURPOSE OF REVIEW

Postherpetic neuralgia is an annoying pain that mainly affects older people. In order to give patients more options, this review summarizes the pharmacological and interventional treatments for postherpetic neuralgia and updates the research on the efficacy, thereby providing doctors with more treatment options. The adverse effects and effective doses of its various treatments are also presented so that the therapy can be prescribed according to their concrete physical conditions. In a word, this review is dedicated to providing a comprehensive overview of the treatment options for postherpetic neuralgia and offering patients more choices.

RECENT FINDINGS

Combinational therapy is more excellent than monotherapy. The local anesthesia and gabapentin comprised outstanding compatibility. In addition, two therapeutic tools for PHN patients, especially for the intractable ones, electroacupuncture (EA), and osteopathic manipulative treatment (OMT), show their efficacy and become potential options to alleviate pain. In terms of treatment, guidelines recommend patients use tricyclic antidepressants (TCAs), gabapentin, pregabalin, and 5% lidocaine patches as the first-line medications, and gabapentin is investigated most, especially the gabapentin enacarbil (GEn). And drug efficacy can be limited by adverse effects and tolerated doses. Interventional treatments, with their invasiveness and operational difficulty, are usually considered for intractable patients. Combinational therapies may be used when a single therapy cannot achieve the desired effect. Therapies such as OMT and EA have also been proposed to palliate pain in some cases, and future directions of treatment may be investigated in Chinese medicine and acupuncture.

Comparison of the Severity of Zoster-Associated Pain and Incidence of Postherpetic Neuralgia in Patients with and without Pre-Existing Spinal Disorders at the Same Spinal Nerve Level: A Retrospective Multicenter Study

The incidences of herpes zoster (HZ) and postherpetic neuralgia (PHN) are significantly influenced by age. As individuals age, the occurrence of spinal disorders increases, thereby raising the likelihood of HZ and PHN coexistence. Considering this, our study aimed to explore the potential impact of pre-existing spinal disorders at the nerve level where HZ developed, on the severity of zoster-associated pain (ZAP) and the incidence of PHN. For our investigation, we retrospectively analyzed a total of 237 patients who presented with HZ and ZAP at various sensory levels (cervical, thoracic, lumbar, and sacral) with or without pre-existing spinal disorders. The presence or absence of spinal disorders at the sensory level affected by HZ was determined using computed tomography or magnetic resonance imaging. Our study results revealed that the group with spinal disorders at the sensory level where HZ developed did not exhibit an increased incidence of PHN. However, 3-6 months after HZ onset, this same group showed significantly higher ZAP scores compared to the group without spinal disorders. It implies a need for heightened pain management, as the coexistence of these conditions can increase pain severity. This study furnishes an initial standpoint to delve into intricate interactions between two diseases.

A Case Report of Refractory Postherpetic Neuralgia After Ramsay Hunt Syndrome Treated With Tympanic Nerve Neurectomy

Ramsay Hunt syndrome is a facial nerve palsy that arises from herpes zoster infection. In rare cases, postherpetic neuralgia is a complication following Ramsay Hunt syndrome. Pain management to address postherpetic neuralgia includes facial nerve blocks, medications such as gabapentin, carbamazepine and botulinum toxin injections, and pulsed radiofrequency. Despite the reported benefits for patients with glossopharyngeal nerve pain, neurectomy as a treatment has rarely been described. A 45-year-old patient visited our ENT clinic for chronic right-sided facial, ear, and jaw pain that persisted for 9 years following the development of Ramsay Hunt syndrome. She trialed multiple medications including gabapentin, carbamazepine, and botulinum toxin injections with minimal relief to her symptoms. The patient underwent a diagnostic myringotomy with topical application of lidocaine to the tympanic nerve. This resulted in temporary relief of her pain until the effects of the lidocaine subsided. The patient was subsequently offered lysis of the right tympanic nerve for more definitive management. The patient experienced significant pain reduction after the right tympanic neurectomy procedure. Chronic postherpetic neuralgia following Ramsay Hunt syndrome can cause significant impairment in a patient's quality of life. For patients with ear pain refractory to conservative management, a tympanic neurectomy can be considered.

Superior laryngeal nerve block for treatment of throat pain and cough following laryngeal herpes zoster: A case report

BACKGROUND

Herpes zoster is caused by reactivation of latent varicella-zoster virus infection within the sensory nerve ganglion of the spinal or cranial nerves. Laryngeal herpes zoster is rare and involves superior laryngeal nerve, which leads to several complications such as throat pain, and cough.

CASE SUMMARY

Patient concerns: A 52-year old woman presented with a 70 d history of throat pain and a 67 d history of non-productive cough. Three days after onset of pain, she was diagnosed with laryngeal herpes zoster. Flexible nasolaryngoscopy revealed multiple white ulcerated lesions on the left hemi epiglottis and the left supraglottic area. She was prescribed with 750 mg famciclovir a day for 7 d, and 150 mg pregabalin, 100 mg tramadol and 10 mg nortriptyline a day for 67 d. However, despite of these medications, she complained of pain and persistent cough. Therefore, superior laryngeal nerve block under ultrasound guidance was performed. Three days after the intervention, the throat pain and cough disappeared. The patient remained symptom-free at 3 mo follow-up.

CONCLUSION

A superior laryngeal nerve block can be an effective option for treatment of pain and cough following laryngeal herpes zoster.

REAC Antalgic Neuro Modulation in Chronic Post Herpetic Neuralgia

BACKGROUND

Chronic post-herpetic neuralgia (CPHN) is a symptomatic condition that afflicts adults and elderly individuals. The chronicity of this symptomatology can be conditioned by the epigenetic modifications induced by the virus on the processes of neurotransmission and sensitivity to pain. The aim of this study is to investigate whether manipulating endogenous bioelectrical activity (EBA), responsible for neurotransmission processes and contributing to the induction of epigenetic modifications, can alleviate pain symptoms.

METHODS

This manipulation was carried out with the antalgic neuromodulation (ANM) treatment of radioelectric asymmetric conveyer (REAC) technology. Pain assessment before and after treatment was performed using a numerical analog scale (NAS) and a simple descriptive scale (SDS).

RESULTS

The results of the analysis showed an over four-point decrease in NAS scale score and over one point decrease in SDS scale score, with a statistical significance for both tests of p < 0.005.

CONCLUSIONS

The results obtained in this study demonstrate how REAC ANM manipulation of EBA can lead to improvement in epigenetically conditioned symptoms such as CPHN. These results should prompt further research to expand knowledge and ensure optimized therapeutic outcomes.

Adjuvanted recombinant zoster vaccine decreases herpes zoster-associated pain and the use of pain medication across 3 randomized, placebo-controlled trials

ABSTRACT

Herpes zoster (HZ) and HZ-associated pain greatly affect patients' quality of life, particularly in older and immunocompromised adults, for whom comorbidities and polypharmacy are often reported. Three phase III, randomized, placebo-controlled clinical trials have reported the adjuvanted recombinant zoster vaccine (RZV) as highly efficacious in preventing HZ and reducing pain severity in healthy adults ≥50 years old (Zoster Efficacy Study [ZOE]-50 study, NCT01165177) and ≥70 years old (ZOE-70; NCT01165229) and in immunocompromised adults ≥18 years old undergoing autologous hematopoietic stem cell transplantation (ZOE-HSCT; NCT01610414). Here, we investigated efficacy of RZV in reducing (i) the duration of clinically significant pain (Zoster Brief Pain Inventory pain score ≥3) and (ii) HZ-associated pain medication use and duration of use in participants with confirmed HZ ("breakthrough cases") from the 3 studies. Recombinant zoster vaccine effectively reduced the duration of clinically significant HZ-associated pain during HZ episodes by 38.5% ( P -value: 0.010) in the ZOE-HSCT study. Although a similar trend was observed in the ZOE-50 and ZOE-70 studies, the results were not statistically significant because of the high vaccine efficacy (VE) against HZ resulting in rare breakthrough cases. VE in reducing pain medication use (39.6%; P -value: 0.008) and duration of medication use (49.3%, P -value: 0.040) was reported in the ZOE-70 study; corresponding positive VE estimates were observed in the ZOE-50 and ZOE-HSCT studies but were not statistically significant. Data reported here demonstrate efficacy of RZV in reducing HZ-associated pain duration and pain medication use in breakthrough cases, thereby improving quality of life of those with HZ.

Autologous fat grafting to the paravertebral space seems to prevent the postherpetic neuralgia-A single-arm pilot study

INTRODUCTION

Postherpetic neuralgia (PHN) is one of the most common complications of Herpes zoster (HZ), yet the mechanism and the treatment for PHN remains elusive. We first performed this feasibility study to verify the safety and efficiency of autologous fat grafting into the paravertebral space in early HZ to prevent PHN.

METHODS

Patients suffering from HZ with a rash in chest, back, or abdomen were arranged for autologous fat grafting to the paravertebral space. The primary endpoint was the incidence of PHN, which was defined as persistence pain in the affected dermal area in 12 weeks after fat grafting. Secondary endpoints including patient-reported changes in pain intensity, assessed pain threshold and the quality of life during follow-ups.

RESULTS

Eight patients accept the intervention and completed all follow-ups. Most patients report immediate pain relief after injection, one patient has a mild to moderate dizzy symptom after injection. No other short- or long-term adverse events occurred. For primary outcome, all patients have a timely reduced pain intensity, with no PHN events occurred, as all patients report pain intensity ≤3 in the VAS scale in 3 months after treatment. For electrical pain threshold, we identify that fat grafting differentially increases sensation and pain threshold in HZ area and healthy skin of patients. Besides, our results indicate significant improvement in patients' life quality decrease in analgesic consumption.

DISCUSSION

Autologous fat transplantation to the paravertebral space is a safe and feasible technique in preventing PHN from HZ in a rash. Further randomized controlled trial to investigate the actual long-term benefice of autologous fat grafting to the paravertebral space in preventing PHN is needed.

TRIAL REGISTRATION

ChiCTR, (ChiCTR1900025416); registered August 26, 2019.

Bibliometric analysis of research articles on post-herpetic neuralgia published from 1991 to 2020

Post-herpetic neuralgia (PHN) is one of the most painful diseases, which has made it a major concern for pain physicians. We aimed to quantitatively analyze the research outputs of studies on PHN published over the past 30 years using bibliometric analysis. We also aimed to analyze the research outputs of studies on interventional treatments for PHN and evaluate the academic achievements of Korean pain physicians. Bibliometric analysis was performed by searching the Web of Science database for PHN-related articles published between 1991 and 2020. Publication number, year, source, country, institution, and citation-related information were retrieved from the database. We also quantitatively analyzed publications related to interventional treatments for PHN. A total of 3285 publications were extracted from the database; 101 (3.1%) of the articles were published by South Korean authors, making South Korea the 11th in the order of countries that published the most articles. There were 185 articles on the effects of interventional treatments for PHN. South Korean authors published 30 (16.2%) articles out of these, making South Korea the 3rd in the order of countries that published the most articles on the effects of interventional treatment for PHN. Our results showed an increasing trend in the number of PHN-related publications and the academic achievements of Korean pain physicians in this field over the past 3 decades. However, the proportion of studies on interventional treatments is relatively small. Korean pain physicians need to establish academic evidence on interventional treatment to expand their role in this field and improve the outcomes of PHN patients.

Greater functional connectivity between the ventral frontal cortex and occipital cortex in herpes zoster patients than post-herpetic neuralgia patients

OBJECTIVE

This study aimed to compare whole brain network between herpes zoster (HZ) patients and post-herpetic neuralgia (PHN) patients, as well as to investigate the associations between whole brain network changes and pain intensity and the accuracy of classifying between different types of pain.

METHODS

PHN patients (n = 50) and HZ patients (n = 50) and healthy controls (HCs) (n = 50) underwent resting-state functional magnetic resonance imaging (rs-fMRI). Functional connectivity and global and local graph theory metrics were calculated by using Dosenbach-160 atlas. The relationship between neuroimaging indicators and clinical scales was evaluated using correlation analysis, and receiver operating characteristic (ROC) curves evaluated the feasibility of classifying PHN and HZ patients using specific neuroimaging indicators.

RESULTS

(1) 10 greater average connectivities were found in HZ group among the default mode, frontoparietal, cingulo-opercular, sensorimotor, occipital networks (ONs), and cerebellum (p < 0.001). (2) HZ patients exhibited higher global efficiency than those in the PHN and HCs (t = 2.178, p = 0.038). (3) Multiple linear regression analyses indicated that functional connectivity between the ventral frontal cortex in the cingulo-opercular network and the occipital gyrus in the ON influenced the visual analog score pain scores (β = 4.273; p = 0.004).

CONCLUSION

The variation of functional connectivity between ventral frontal cortex in the cingulo-opercular network and occipital gyrus in the ON may be a robust neuroimaging marker of the transition from HZ to PHN patients.

ADVANCES IN KNOWLEDGE

Whole-brain network analysis may be effective in distinguishing HZ and PHN patients and predicting pain intensity.

Current scenario and future applicability of antivirals against herpes zoster

Herpes zoster (HZ) is a common disease in the aging population and immunocompromised individuals, with a lifetime risk of 20%-30% that increases with age. HZ is caused by reactivation of the varicella-zoster virus (VZV), which remains latent in the spinal dorsal root ganglia and cranial sensory ganglia after resolution of the primary VZV infection. The main focus of HZ management is rapid recovery from VZV infection as well as the reduction and prevention of zoster-associated pain (ZAP) and postherpetic neuralgia (PHN). The use of antivirals against VZV is essential in the treatment of HZ. However, limited antivirals are only licensed clinically for the treatment of HZ, including acyclovir, valacyclovir, famciclovir, brivudine, and amenamevir. Fortunately, some new antivirals against different types of Herpesviridae have been investigated and suggested as novel drugs against VZV. Therefore, this review focuses on discussing the difference in efficacy and safety in the currently licensed antivirals for the treatment of HZ, the applicability of future novel antivirals against VZV, and the preventive or therapeutic effects of these antivirals on ZAP or PHN.

Oral herbal medicine for treatment of postherpetic neuralgia: A protocol for systematic review and meta-analysis

BACKGROUND

Postherpetic neuralgia (PHN) is the most common complication of shingling. Herbal medicine for PHN is clinically used to improve chronic pain and other symptoms that reduce the quality of life (QoL), such as sleep disturbances and emotional problems. This study aims to describe methods for synthesizing evidence for the effectiveness and safety of herbal medicine for treating PHN.

METHODS

Randomized controlled trials using herbal medicine in patients with PHN will be included in this review. Electronic databases such as MEDLINE via PubMed, EMBASE, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Infrastructure, WanFang, KoreaMed, Research Information Service System, Korean Studies Information Service System, Database Periodical Information Academic, Oriental Medicine Advanced Searching Integrated System, and Korea Citation Index will be searched without language limitations from their inception to September 2022. Two authors will perform quality assessments independently using the Cochrane risk-of-bias tool. The primary outcome will be pain intensity, and the secondary outcomes will be global impression, anxiety, depression, sleep disturbance, QoL, and safety. All data from eligible studies will be synthesized for meta-analysis.

RESULTS

This study will be a systematic review and meta-analysis to evaluate the effectiveness and safety of oral herbal medicine for treatment of PHN.

CONCLUSION

This study will provide evidence for herbal medicine as a potential treatment for PHN which is advantageous not only for patients but also for researchers and policymakers.

The Contrasting Seasonality Patterns of Some Cancer-Types and Herpes Zoster Can Be Explained by a Binary Classification of Immunological Reactions

A binary classification of the pathogenic immune reactions as anti-inflammatory high-Treg reactions or pro-inflammatory low-Treg reactions explains both the relatively low incidence rate of several types of cancer, and the relatively high incidence rate of herpes zoster cases diagnosed in the summer compared to cases diagnosed in the winter (in regions with temperate climate). This binary model also elucidates the longer survival of cancer patients diagnosed during the summer compared to these diagnosed in the winter. The three key elements of this explanation are: (a) the effect of sunlight on Treg production; (b) the evolvement of cancer from a low-Treg condition at early stage, to a high-Treg condition at advanced stage, and (c) the evolvement of herpes zoster from a high-Treg condition at pre-exudative stage to a low-Treg condition at acute exudative stage. A significant proportion of indolent tumors at the time of diagnosis (>20%) is a prerequisite for a beneficial effect of sunlight on cancer incidence rate and prognosis. This prerequisite restricts the beneficial effect of diagnosis during summer to certain types of cancer. Clinical implication: the prognosis of early stage tumors may be improved by a course of corticosteroid (or other immunosuppressant) treatment.

Interventions for zoster-associated pain: A retrospective study based on the clinical database

Background

Herpes zoster (HZ)-associated pain can lead to severe pain and reduced quality of life. Exploring effective treatment and the risk factors of zoster-associated pain has become important.

Methods

Interventions including nerve block, radiofrequency, and thermocoagulation were used for zoster-associated pain. The data of 131 patients with HZ and 230 patients with postherpetic neuralgia (PHN) were collected at baseline, 2 weeks, 3, 6, and 12 months after the intervention. Visual analog scale (VAS) and Brief Pain Inventory (BPI) scores at different time points were analyzed by two-way repeated measures ANOVA with Group as the between-subject variable (different pain durations and areas), Time as the within-subject variable (baseline, 2 weeks, 3 months, 6 months, and 12 months), and Group × Time as the two-way interaction. Besides, the effective rate, adverse effects, and medication were also recorded. The risk factors of PHN were analyzed by logistic regression.

Results

A total of 25 (19.08%) patients with HZ continued to have pain in the initially affected area after 3 months. The VAS scores and the BPI quality of life scores of patients with HZ-associated pain were significantly reduced from baseline to 2 weeks, 3, 6, and 12 months after the interventions. There was no significant difference in VAS and BPI scores in different pain areas and pain durations. No significant Group × Time interaction was observed. Age, diabetes mellitus, and immune-related diseases were risk factors of PHN.

Conclusion

Interventions could significantly improve the pain degree and life quality of patients with zoster-associated pain, and the positive effect of intervention did not change with pain duration and area. Advanced age, diabetes, and immune-related diseases are risk factors of PHN.

Comparison of Adjuvant Hypertonic Saline and Normal Saline for Epidural Block in Patients with Postherpetic Neuralgia: A Double-Blind, Randomized Trial

Background

In patients with postherpetic neuralgia (PHN), the effectiveness of epidural block and the benefits of adjuvant hypertonic saline (HS) have not been fully determined. Therefore, we investigated these issues in this study.

Methods

At a tertiary medical center's single pain clinic in Seoul, Republic of Korea, patients complaining of PHN even after 4 months of herpes zoster onset were enrolled and randomly assigned to either the HS or normal saline (NS) group. After epidural block with adjuvant HS or NS administration according to each protocol, outcomes were assessed at baseline and one and three months after the intervention. The primary outcome was pain intensity on the numerical rating scale (NRS). The secondary outcomes were the insomnia severity index (ISI), the medication quantification scale (MQS), and the global perceived effect of satisfaction (GPES).

Results

Thirty-six patients (NS: 17, HS: 19) were included in the intention-to-treat analysis. The estimated pain intensity decreased in both groups at one and three months after the procedure (P < 0.001), without a significant group difference. The estimated ISI and MQS were not significantly different at 1 month compared with baseline but significantly decreased at 3 months in each group (P < 0.001 and P < 0.001, respectively), without group differences. In addition, there was no difference between the groups on the GPES scale at one and three months after the procedure.

Conclusions

Epidural steroid injection may have the advantages of short-term pain relief, improved sleep quality, and decreased medication usage in patients with PHN. In addition, adjuvant HS administration with epidural steroid injection did not show beneficial effects in patients with PHN. Further studies are needed to clarify the potential effectiveness of HS in treating neuropathic pain such as PHN. This trial is registered with KCT0002845.

A comparative study between transcutaneous electrical nerve stimulation and pulsed electromagnetic field therapy in the management of post-herpetic neuralgia of the sciatic nerve

OBJECTIVES

To compare the efficacy of pulsed electromagnetic field therapy (PEMFT) versus transcutaneous electrical nerve stimulation (TENS) in the treatment of post-herpetic neuralgia of the sciatic nerve.

METHODS

A double-blinded randomized clinical study has included 56 patients (18 males and 38 females). Participants were randomly and equally assigned into 2 groups. Both groups received conventional physical therapy treatment. Moreover, group (A) has an additional TENS, and group (B) had PEMFT. Both modalities were applied once daily, 3 times a week for 20 minutes for 8 successive weeks. Visual analog scale (VAS) and carbamazepine intake (CMI) dose have been assessed before and after interventions.

RESULTS

There was a significant decrease in VAS and CMI post-treatment in group A and B compared with that pretreatment (P > .001). The percent decrease in VAS and CMI in group A were 72.44% and 69.47% respectively and that for group B was 68.95% and 67.94% respectively. The findings revealed a non-significant difference in VAS and CMI (P > .05) between groups. The Means of VAS and CMI were (2.4 ± 0.78, 204.5 ± 16.76 and 2.67 ± 0.9, 210.57 ± 16.5) in group A and group B respectively. The mean difference for VAS and CMI was (-0.27 and -6.07) between groups post-treatment respectively.

CONCLUSION

Both TENS and PEMFT were effective and nearly equivalent in improving the post-herpetic neuralgia of the sciatic nerve as measured by in VAS and CMI. Clinical recommendations should be highlighted to instigate the using of TENS and PEMFT in the management of post-herpetic neuralgia of the sciatic nerve.

Dermoscopic Differentiation of Blister Beetle Dermatitis and Herpes Zoster: an Observational Study

INTRODUCTION

Blister beetle dermatitis (BBD) and herpes zoster (HZ) manifest suddenly with vesicular lesions mimicking each other and progress rapidly. But a lack of definite differentiating criteria yearns the need for better investigating modality. Though histopathology persuades the need, is an invasive procedure, commonly deferred. Thus, dermoscopy, a non-invasive rapid diagnostic tool, can help in differentiating.

OBJECTIVES

To evaluate different dermoscopic patterns of BBD and HZ to differentiate both and to study dermoscopic features in early and late stages of lesions.

METHODS

An observational cross-section study conducted in southern India. Nine patients with clinical features suggestive of BBD and HZ were recruited. Lesions were divided arbitrarily into early and late. Dermoscopic examination was performed with handheld dermoscope. Diagnosis was confirmed by skin biopsy and Tzanck smear wherever necessary. Statistical analysis performed using data in terms of frequencies and percentages.

RESULTS

Dermoscopy of early BBD lesions showed multiple discrete and confluent yellowish-white structures, brown dots, roundish white globules, gray structures, 'targetoid pattern', brown areas over intense reddish pink background. Late BBD lesions revealed pinkish-white area, reduced gray structures and, dotted and globular vessels. Early HZ lesions showed poly-lobular gray and brown globules, bright pink background, gray globules covered by grayish veil-like structure with gray rim. Late HZ lesions revealed 'solar eclipse' pattern and 'crumpled fabric' patterns. The dermoscopic findings correlated with histopathology.

CONCLUSIONS

Dermoscopic patterns show peculiar features consistently pertaining to BBD and HZ, thus help in early diagnosis assisting in accurate treatment in both conditions.

The relative frequency of pruritus in postherpetic neuralgia patients presenting to the pain clinic and associative factors

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, whereas postherpetic pruritus (PHP) a rare one. Although PHN has been extensively studied, few studies have investigated PHP. The purpose of this study was to investigate PHP incidence and associated factors in patients with PHN. This was a retrospective study of patients with PHN. A total of 645 patients were included. This study conducted in a single university hospital. Data included age, sex, height, weight, pain score, PHN site, medications, nerve blocks, and pulsed radiofrequency treatment. Data also included PHP onset and duration among those with PHP. We divided patients into 2 groups: the control group (group C), comprising those without PHP, and pruritus group (group P), comprising those with PHP. The correlation of PHP with other factors was analyzed. Of 207 patients, 58 were in group P whereas 149 in group C. The mean onset time and duration of PHP were 96.5 and 278.6 days, respectively. Pain scores were lower in group P than in group C after 3 and 4 months following vesicle formation. Patients with PHN in the trigeminal nerve had a higher incidence of PHP compared to those with PHN in others. Twenty-eight percent of patients with PHN developed PHP. At 3 and 4 months after vesicle formation, patients with PHP had greater pain improvement compared to those without. Patients with PHN in the trigeminal nerve also had a higher incidence of PHP compared to others.

Management of patients with neuropathic pain

Background: Neuropathic pain diseases commonly treated with pain medicine are postherpetic neuralgia (PHN), diabetic peripheral neuropathy (DPNP), complex regional pain syndrome (CRPS), and chronic pain after spinal surgery. Diagnosis and treatment of these neuropathic pain diseases is an arduous task, and there is a need to improve the understanding of these entities.Current Concepts: PHN is diagnosed when pain persists for more than 3 months after the healing of herpes zoster rashes, and this disease is commonly encountered in the elderly population. The pathophysiology of DPNP is ischemia of nerve tissue due to microvascular damage. In addition to sensory nerves, DPNP can also result in changes in motor and autonomic nerves. CRPS is a chronic intractable pain disorder, and is classified into types 1 and 2. Type 1 CRPS is diagnosed when there is no evidence of nerve damage while type 2 CRPS shows evidence of nerve damage. However, the signs and symptoms do not differ depending on the type. Chronic pain after spinal surgery is characterized by persistent back pain even after one or more spinal surgeries. This neuropathic pain occurs in the lower back or leg region.Discussion and Conclusion: The most crucial step in the management of patients with neuropathic pain is to suspect and diagnose if the pain has the characteristics of any pain-related disease. Although the etiology and pathophysiology may differ, the treatment of neuropathic pain remains the same and includes both conservative and interventional approaches. Neuropathic pain diseases often become chronic in nature, and thus, it is important to establish a treatment plan which aims at decreasing pain, improving patient’s functionality and attaining an acceptable quality of life.

Cervical Root Enlargement in Segmental Zoster Paresis: A Study with Magnetic Resonance Imaging and Nerve Ultrasound

A 72-year-old woman presented with acute-progressive muscle weakness after a rash in the left upper limb. Muscle weakness was restricted to the left C5 innervated muscles. Short inversion time inversion recovery magnetic resonance imaging (MRI) showed a high-intensity signal in the left C5 nerve root, and nerve ultrasound showed its enlargement. She was diagnosed with segmental zoster paralysis (SZP) and treated with acyclovir and methylprednisolone. Her muscle strength gradually recovered, and the abnormal signal and enlargement in the left C5 nerve root improved. This is the first SZP case of confirmed improvement of abnormal findings on MRI and nerve ultrasound in association with muscle power recovery.

Unusual presentations of thoracic disc herniation treated by thoracic epidural block: Case reports

RATIONALE

Herniation of the thoracic intervertebral disc (HTD) is a rare disease that accounts for <1% of all disc herniations. Physicians may make diagnostic errors due to the variable clinical features and limited experience of HTD. In this report, we present 2 unusual cases of HTD.

PATIENT CONCERNS

A 72-year-old woman (case 1) visited our pain clinic because of chronic abdominal discomfort with visible bulging on the left side. Atrophy of the abdominal wall muscle and quadratus lumborum was observed. The therapeutic effect of interfascial plane block to exclude the possibility of truncal neuropathy following muscular atrophy was temporary. The other patient, a 75-year-old man (case 2) complained of aggravation of previously diagnosed postherpetic neuralgia. An extension of the previously symptomatic area of the forward upper dermatome was observed. Radiofrequency treatment on the symptomatic dorsal root ganglion failed to relieve symptoms.

DIAGNOSES

Two patients underwent magnetic resonance imaging of the spine for further evaluation. The patients were diagnosed with multilevel HTD and foraminal herniated disc, compatible with their symptoms and without myelopathy.

INTERVENTIONS

Two patients were conservatively treated with a fluoroscopy-guided transforaminal epidural block.

OUTCOMES

The 2 patients experienced significant pain reduction up to 50% on a numeric rating scale after repeated treatment.

LESSONS

Multilevel HTD of the mid- to lower-thoracic spine may present as abdominal bulging with atrophy of the abdominal wall muscles. We also report another case of concomitant symptomatic thoracic radiculopathy from HTD and postherpetic neuralgia at the adjacent level. Thoracic transforaminal epidural block may be considered a conservative therapeutic approach for HTD.

Diffusion tensor imaging study of the microstructural changes in the white matter of patients with herpes zoster and postherpetic neuralgia

OBJECTIVE

To determine the association between white matter structural changes and PHN by analyzing the diffusion tensor imaging data of patients with herpes zoster (HZ) or postherpetic neuralgia (PHN), and the volunteered healthy controls (HC).

METHODS

A total of 48 participants with HZ, 40 participants with PHN, and 28 age and sex matched HC were enrolled in this study. The diffusion tensor imaging data were collected by a Siemens 3.0T magnetic resonance scanner, and FSL (FMRIB's software) was used to analyze the differences in diffusion indexes among the HZ, PHN and HC groups. In addition, the correlation between the image and the clinical parameters was analyzed.

RESULTS

The results indicated that the microstructural integrity of the white matter, which affects the information exchange and integration between pain and non-pain related brain regions, showed difference in patients with HZ and PHN.

CONCLUSION

The study may provide an experimental basis for more thorough longitudinal research in the future to explore the changes of brain structure in patients with PHN from HZ and develop adequate treatment strategy.

Development of a perfusion process for serum-free adenovirus vector herpes zoster vaccine production

Herpes zoster is caused by reactivation of the varicella zoster virus (VZV). Researching and developing a herpes zoster vaccine will help to decrease the incidence of herpes zoster. To increase the bioreactor productivity, a serum-free HEK293 cell perfusion process with adenovirus vector herpes zoster (rAd-HZ) vaccine production was developed efficiently using the design of experiment (DoE) method. First, serum-free media for HEK293 cells were screened in both batch and semi-perfusion culture modes. Then, three optimal media were employed in a medium mixture design to improve cell culture performance, and the 1:1 mixture of HEK293 medium and MCD293 medium (named HM293 medium) was identified as the optimal formulation. On the basis of the HM293 medium, the relationship of critical process parameters (CPPs), including the time of infection (TOI), multiplicity of infection (MOI), pH, and critical quality attributes (CQAs) (adenovirus titer (Titer), cell-specific virus yield (CSVY), adenovirus fold expansion (Fold)) of rAd-HZ production was investigated using the DoE approach. Furthermore, the robust setpoint and design space of these CPPs were explored. Finally, the rAd-HZ production process with parameters at a robust setpoint (TOI = 7.2 × 10⁶ cells/mL, MOI = 3.7, and pH = 7.17) was successfully scaled-up to a 3-L bioreactor with an alternating tangential flow system, yielding an adenovirus titer of 3.0 × 10¹⁰ IFU/mL, a CSVY of 4167 IFU/cells, a Fold of 1117 at 2 days post infection (dpi). The DoE approach accelerated the development of a HEK293 serum-free medium and of a robust adenovirus production process.

A Comparison Between Effects of Amenamevir and Famciclovir on Intensities of Acute Pain and the Incidence of Postherpetic Neuralgia in Adult Patients with Herpes Zoster

Objective

Herpes zoster (HZ) is a common disease, whose most common complication is postherpetic neuralgia (PHN). We conducted this study to compare effects of amenamevir (AMNV) and famciclovir (FCV) on intensities of acute HZ pain and the incidence of PHN, which have not been compared yet.

Methods

After approval by the Ethics Committee, we retrospectively investigated adult patients with HZ treated with AMNV or FCV at Juntendo University Hospital between October, 2018 and February, 2020. We compared, between 143 AMNV-treated and 131 FCV-treated patients, pain scores of acute HZ pain evaluated on an 11-point numerical rating scale (NRS) and the incidence of PHN with the Mann-Whitney U test and Pearson's chi-square test, respectively. The univariate logistic regression analysis was used to identify predictors of PHN.

Results

Pain scores during the acute HZ period remained significantly lower in AMNV-treated patients than FCV-treated patients (p = 0.049, 0.011, and 0.016 for Day 3-4, Day 7, and Week 2-3, respectively), although the pain score at Day 0 before treatment didn't differ between them (p > 0.05). The incidence of PHN didn't differ between them (9.8% vs. 11.5%, p > 0.05). In the total cohort, the pain score at Week 2-3 was significantly associated with the development of PHN (r 2 = 0.180, p < 0.00001).

Conclusions

Compared with FCV, AMNV was more effective in reducing acute HZ pain, possibly reflecting its unique mechanism of action. However, AMNV didn't reduce the incidence of PHN possibly due to the multifactorial etiology of PHN.

Determining the Definitive Time Criterion for Postherpetic Neuralgia Using Infrared Thermographic Imaging

Introduction

The time criteria used in many studies of postherpetic neuralgia (PHN) are arbitrary and do not have supporting evidence. Therefore, this study sought to determine the definite time criterion for PHN by analyzing the skin temperature to estimate the time point when zoster-induced skin inflammatory reaction ends.

Methods

Infrared thermography was used to measure the difference in skin temperature between the affected and unaffected areas (ΔTemp) in the craniocervical and thoracic regions of patients with herpes zoster (HZ). Because the ΔTemp changes from a positive value to zero when the skin is no longer inflamed, a ΔTemp ≤ 0 was defined as the end of skin inflammation, and this time point was considered the starting point for PHN. This cutoff time point was estimated using receiver operating characteristic (ROC) curve analysis.

Results

A total of 503 patients were included in this study. The ROC curve analysis showed that the time point when the ΔTemp was ≤ 0 occurred at 12 weeks after HZ onset (95% confidence interval 11–15 weeks, area under the ROC curve 0.901). Using this time point as the time criterion of PHN, the sensitivity, specificity, and classification accuracy were 0.807, 0.905, and 0.871, respectively.

Conclusions

The transition of skin temperature from warm to cold occurs 12 weeks after HZ onset, which implies the end of local inflammation. Therefore, PHN associated with pathophysiologic change may be defined as 12 weeks after the skin rash. This finding provides a theoretical basis for the timing definition of PHN.

Altered gray matter volume and functional connectivity in patients with herpes zoster and postherpetic neuralgia

Numerous neuroimaging studies on postherpetic neuralgia (PHN) and herpes zoster (HZ) have revealed abnormalities in brain structure/microstructure and function. However, few studies have focused on changes in gray matter (GM) volume and intrinsic functional connectivity (FC) in the transition from HZ to PHN. This study combined voxel-based morphometry and FC analysis methods to investigate GM volume and FC differences in 28 PHN patients, 25 HZ patients, and 21 well-matched healthy controls (HCs). Compared to HCs, PHN patients exhibited a reduction in GM volume in the bilateral putamen. Compared with HZ patients, PHN patients showed decreased GM volume in the left parahippocampal gyrus, putamen, anterior cingulate cortex, and right caudate and increased GM volume in the right thalamus. However, no regions with significant GM volume changes were found between the HZ and HC groups. Correlation analysis revealed that GM volume in the right putamen was positively associated with illness duration in PHN patients. Furthermore, lower FCs between the right putamen and right middle frontal gyrus/brainstem were observed in PHN patients than in HCs. These results indicate that aberrant GM volumes and FC in several brain regions, especially in the right putamen, are closely associated with chronification from HZ to PHN; moreover, these changes profoundly affect multiple dimensions of pain processing. These findings may provide new insights into the pathophysiological mechanisms of PHN.

The effect of subcutaneous injection of methylprednisolone acetate and lidocaine for refractory postherpetic neuralgia: a prospective, observational study

BACKGROUND

Postherpetic neuralgia (PHN) is the most common and bearable complication of herpes zoster (HZ). This pain may have negative impact on the patient's all aspects of daily life and health-related quality of life (HRQOL). Despite numerous advances in treatment, many patients remain resistant to the current therapy options. It is the first time subcutaneous injection of methylprednisolone acetate and lidocaine has been used to treat refractory PHN. We report the results of this treatment evaluating pain relief and HRQOL improvement in this disorder.

METHODS

A total of 43 patients with refractory PHN was enrolled in the observational study. All patients received daily subcutaneous injection of methylprednisolone acetate and lidocaine for 10 consecutive days. The severity of pain was assessed by using Visual Analog Scale (VAS), and 36-Item Short Form Survey (SF-36) was applied to evaluate HRQOL. Assessment of the pain and HRQOL was carried out at baseline and posttreatment at 4 weeks as well as 6 and 12 months.

RESULTS

At baseline, all patients experienced severe PHN with average VAS scores of 8.44 ± 0.85 (minimum 7; maximum 10). At 4 weeks, 6 months, and 12 months after treatment, the pain had significantly decreased (P < .001), and all subjects showed significant improvement in all eight domains of HRQOL. No major adverse events associated with the subcutaneous injection were observed.

CONCLUSIONS

Our results indicate that subcutaneous injection of methylprednisolone acetate and lidocaine can be an effective and safe treatment for PHN.

Unusual presentation of Ramsay-Hunt Syndrome in kidney transplant patient

Herpes Zoster (HZ) is caused by reactivation of latent varicella zoster virus (VZV) in craniospinal sensory neurons and is characterized by a painful erythematous rash in the affected dermatome. Although kidney transplant recipients who are chronically maintained on immunosuppressive regimens are considered at risk, there are only a few cases described. We report a well-documented case of a 50-year-old male kidney transplant recipient who presented Ramsay-Hunt syndrome with atypical neurological finds.

Pulsed Radiofrequency of the Trigeminal Ganglion for Treating Postherpetic Neuralgia of the Ophthalmic Branch

Postherpetic neuralgia (PHN) is a painful, long-lasting condition as a consequence of nerve damage resulting from a herpes zoster infection. Although there are many different treatments available to reduce pain duration and severity, PHN is often refractory to them and no single therapy shows an effective cure for all cases of PHN, especially for those involving the ophthalmic branch of the trigeminal nerve. Pulsed radiofrequency (PRF) is a minimally invasive procedure for pain treatment that has been practiced over the past decade. However, its clinical efficacy and safety for treating PHN involving the ophthalmic branch of the trigeminal nerve have not been evaluated. Objective. This study aimed to evaluate the efficacy and safety of PRF for treating PHN involving the ophthalmic branch of the trigeminal ganglion. Study Design. An observational study. Setting. All patients received PRF of the ophthalmic branch of the trigeminal nerve, pain intensity was assessed by a visual analogue scale (VAS), and complications before and after PRF stimulation were noted. Methods. Thirty-two patients with PHN of the ophthalmic branch were treated by PRF of the ophthalmic branch with controlled temperature at 42°C for 8 min. Pain relief, corneal reflex, sleep quality, and satisfaction were assessed for all patients. Results. Thirty out of 32 patients (93.75%) reported significant pain reduction after PRF treatment. Twenty-eight of them (87.5%) were satisfied with their sleep and obtained a pain score lower than 3 following the procedure. Only two patients had a recurrence of the severe burning pain and returned to the hospital for other medical therapies 2 weeks after the PRF procedure. No patient lost the corneal reflex. Limitations. This study is an observational study and a nonprospective trial with a short-term follow-up period. Conclusion. PRF of the trigeminal ganglion of the ophthalmic branch can significantly reduce pain sensation and improve sleep quality and satisfaction for PHN of the ophthalmic branch.

Burst Stimulation of the Thoracic Spinal Cord near a Cardiac Pacemaker in an Elderly Patient with Postherpetic Neuralgia: A Case Report

New developments in spinal cord stimulation (SCS) have improved the treatment of patients with chronic pain. Although the overall safety of modern SCS has been established, there are no published reports regarding safety considerations when implanting a burst-mode spinal cord stimulator in patients with permanent cardiac pacemakers (PCPs). An 80-year-old man with a complete atrioventricular block implanted with a PCP was considered as a candidate for burst-mode SCS due to well-established postherpetic neuralgia (>180 days after rash). Cardiac monitoring during the burst-mode spinal cord stimulator trial and insertion did not indicate any interference. After the insertion of the burst-mode spinal cord stimulator, the patient showed functional improvement and significant pain relief. The safety of traditional tonic-mode SCS in patients with PCP has been previously reported. This is the first case report describing the safe and effective use of burst-mode SCS in a patient with PCP.

Structural and functional brain abnormalities in postherpetic neuralgia: A systematic review of neuroimaging studies

In recent decades, an increasing number of neuroimaging studies utilizing magnetic resonance imaging (MRI) have explored the differential effects of postherpetic neuralgia (PHN) on brain structure and function. We systematically reviewed and integrated the findings from relevant neuroimaging studies in PHN patients. A total of 15 studies with 16 datasets were ultimately included in the present study, which were categorized by the different neuroimaging modalities. The results revealed that PHN was closely associated with structural/microstructural and functional abnormalities of the brain mainly located in the 'pain matrix', including the thalamus, insula, parahippocampus, amygdala, dorsolateral prefrontal cortex, precentral gyrus and inferior parietal lobe, as well as other regions, such as the precuneus, lentiform nucleus and brainstem. Furthermore, a disruption of multiple networks, including the default-mode network, salience network and limbic system, may contribute to the neurophysiological mechanisms underlying PHN. The findings indicate that the cerebral abnormalities of PHN were not restricted to the pain matrix but extended to other regions, profoundly affecting the regulation and moderation of pain processing in PHN. Future prospective and longitudinal neuroimaging studies with larger samples will elucidate the progressive trajectory of neural changes in the pathophysiological process of PHN.

Abnormal Intrinsic Brain Activity and Neuroimaging-Based fMRI Classification in Patients With Herpes Zoster and Postherpetic Neuralgia

Objective: Neuroimaging studies on neuropathic pain have discovered abnormalities in brain structure and function. However, the brain pattern changes from herpes zoster (HZ) to postherpetic neuralgia (PHN) remain unclear. The present study aimed to compare the brain activity between HZ and PHN patients and explore the potential neural mechanisms underlying cognitive impairment in neuropathic pain patients. Methods: Resting-state functional magnetic resonance imaging (MRI) was carried out among 28 right-handed HZ patients, 24 right-handed PHN patients, and 20 healthy controls (HC), using a 3T MRI system. The amplitude of low-frequency fluctuation (ALFF) was analyzed to detect the brain activity of the patients. Correlations between ALFF and clinical pain scales were assessed in two groups of patients. Differences in brain activity between groups were examined and used in a support vector machine (SVM) algorithm for the subjects' classification. Results: Spontaneous brain activity was reduced in both patient groups. Compared with HC, patients from both groups had decreased ALFF in the precuneus, posterior cingulate cortex, and middle temporal gyrus. Meanwhile, the neural activities of angular gyrus and middle frontal gyrus were lowered in HZ and PHN patients, respectively. Reduced ALFF in these regions was associated with clinical pain scales in PHN patients only. Using SVM algorithm, the decreased brain activity in these regions allowed for the classification of neuropathic pain patients (HZ and PHN) and HC. Moreover, HZ and PHN patients are also roughly classified by the same model. Conclusion: Our study indicated that mean ALFF values in these pain-related regions can be used as a functional MRI-based biomarker for the classification of subjects with different pain conditions. Altered brain activity might contribute to PHN-induced pain.

Disrupted default mode network dynamics in recuperative patients of herpes zoster pain

Introduction

Previous studies of herpes zoster (HZ) have focused on acute patient manifestations and the most common sequela, postherpetic neuralgia (PHN), both serving to disrupt brain dynamics. Although the majority of such patients gradually recover, without lingering severe pain, little is known about life situations of those who recuperate or the brain dynamics. Our goal was to determine whether default mode network (DMN) dynamics of the recuperative population normalize to the level of healthy individuals.

Methods

For this purpose, we conducted resting‐state functional magnetic resonance imaging (fMRI) studies in 30 patients recuperating from HZ (RHZ group) and 30 healthy controls (HC group). Independent component analysis (ICA) was initially undertaken in both groups to extract DMN components. DMN spatial maps and within‐DMN functional connectivity were then compared by group and then correlated with clinical variables.

Results

Relative to controls, DMN spatial maps of recuperating patients showed higher connectivity in middle frontal gyrus (MFG), right/left medial temporal regions of cortex (RMTC/LMTC), right parietal lobe, and parahippocampal gyrus. The RHZ (vs HC) group also demonstrated significant augmentation of within‐DMN connectivity, including that of LMTC‐MFG and LMTC‐posterior cingulate cortex (PCC). Furthermore, the intensity of LMTC‐MFG connectivity correlated significantly with scoring of pain‐induced emotions and life quality.

Conclusion

Findings of this preliminary study indicate that a disrupted dissociative pattern of DMN persists in patients recuperating from HZ, relative to healthy controls. We have thus provisionally established the brain mechanisms accounting for major outcomes of HZ, offering heuristic cues for future research on HZ transition states.

Recombinant zoster vaccine (Shingrix®): a new option for the prevention of herpes zoster and postherpetic neuralgia

Postherpetic neuralgia (PHN) is a challenging condition for pain management specialists. The prevention of herpes zoster (HZ) and subsequent PHN in individuals aged 50 years and older, via the development of new vaccines, is an ongoing research project. The live zoster vaccine (LZV, Zostavax^®) was the first proof of concept that vaccination could prevent HZ, but LZV cannot be used in various immune-compromised patients. This led to the development of a new non-live recombinant zoster vaccine (RZV, Shingrix^®). This RZV has shown promising results in many clinical trials, with high reactogenicity and similar systemic adverse effects compared to those of LZV. The National Advisory Committee on Immunization has recommended LZV as a standard vaccine for HZ prevention in adults ≥ 50 years of age, but no studies directly comparing the safety and efficacy of RZV and LZV vaccines have been conducted. This article reviews the brief history, efficacy, and safety of the two vaccines and discusses the advantage of RZV over LZV based on the available literature.

Zoster sine herpete: a review

Zoster sine herpete (ZSH) is one of the atypical clinical manifestations of herpes zoster (HZ), which stems from infection and reactivation of the varicella-zoster virus (VZV) in the cranial nerve, spinal nerve, viscera, or autonomic nerve. Patients with ZSH display variable symptoms, such as neuralgia, however, different from HZ, ZSH show no zoster, which makes clinical diagnosis difficult. ZSH not only causes initial symptoms, such as neuropathic pain in the affected nerve, Bell palsy, and Ramsay Hunt syndrome, but also postherpetic neuralgia and fatal complications such as VZV encephalitis and stroke. The misdiagnosis of ZSH and tardy antiviral treatment may lead to severe ZSH sequelae. We review the publications related to ZSH, especially its diagnosis with VZV DNA and/or anti-VZV immunoglobulin (IgG and IgM). More work about ZSH, especially ZSH epidemiological survey and guidelines for its diagnosis and treatment, are needed because most of the present studies are case reports.

Comparison of ropivacaine with ropivacaine and fentanyl in continuous epidural analgesia for postherpetic neuralgia: A STROBE-compliant retrospective study

Continuous epidural analgesia (CEA) using local anesthetics is frequently used to control herpes zoster pain and prevent postherpetic neuralgia (PHN). However, few studies have been conducted to determine the efficacy of epidural drugs administered as CEA to manage PHN. This retrospective study was designed to evaluate the effectiveness of CEA with ropivacaine alone or with ropivacaine and fentanyl for controlling pain caused by PHN.We reviewed the medical records of 71 patients. We studied 2 groups: epidural ropivacaine (ER; CEA with ropivacaine alone; n = 44) and epidural ropivacaine and fentanyl (Epidural ropivacaine and fentanyl (ERF); CEA with ropivacaine and fentanyl; n = 27). To evaluate pain, a numeric rating scale (NRS) was evaluated at 6 time points: immediately before the procedure (baseline NRS score); 1 hour after the procedure; 14 days after the procedure; and 1, 3, and 6 months after the procedure. Complication rates were recorded during CEA. We also investigated whether additional invasive procedures were needed due to insufficient pain control during the 6-month follow-up period.After adjusting for confounding variables, there were no significant differences in the NRS scores between the 2 groups at any time point. The adjusted odds ratio for additional invasive procedures within 6 months after CEA was 1.03-times higher in the ERF group than in the ER group, but this difference was not statistically significant (95% confidence interval: 0.33-3.23, P = .96). Rates of complication (dysuria, vomiting, nausea, itching sensation, and hypotension) during CEA were higher in the ERF group than in the ER group. However, the differences were not statistically significant.There was no difference in the management of pain in patients with PHN between the groups. Epidural administration of fentanyl with ropivacaine did not improve pain management when compared to ropivacaine alone. Although not statistically significant, the incidence of complications during CEA was higher in the opioid combination group.

Comparison of the Analgesic Effect of Ropivacaine with Fentanyl and Ropivacaine Alone in Continuous Epidural Infusion for Acute Herpes Zoster Management: A Retrospective Study

Background and Objectives: Currently, few studies have reported the effects of opioids during continuous epidural infusion (CEI) to control pain owing to herpes zoster (HZ). This study aimed to retrospectively compare the effectiveness of epidural opioids in the treatment of acute HZ pain. Materials and Methods: We reviewed medical records of 105 patients who were divided into two groups: R group (CEI with ropivacaine) and RF group (CEI with ropivacaine and fentanyl). Clinical efficacy was evaluated using the numeric rating scale (NRS) score for 6 months after the procedures. We compared the percentage of patients with complete remission in each group. We investigated the complication rates during CEI. Results: No significant differences in the NRS scores were observed between the two groups in the 6-month period. The adjusted odds ratio (OR) for patients included in the complete remission was 0.6 times lower in the RF group than in the R group (95% confidence interval: 0.22–1.71, p = 0.35). The OR for complications during CEI was higher in the RF group than in the R group. However, the difference was not statistically significant. Conclusions: No difference was observed in the management of HZ pain and the prevention of postherpetic neuralgia between the two groups. The incidence of complications tended to be higher in the RF group than in the R group.

A case report of Ramsay Hunt syndrome in a patient with HIV treated by dual-wavelength photodynamic therapy

In this paper we report on the application of dual-wavelength photodynamic therapy with a topical chlorin-based photosensitizer for treatment of Ramsay Hunt syndrome in a patient with HIV. Traditional treatment approach (combination of acyclovir and a glucocorticosteroid) failed to provide a significant outcome, while photodynamic therapy resulted in fast positive dynamics. No recurrence was observed in a 5-month-long follow-up.

Comparison of the efficacy of continuous epidural block with epidural electrical stimulation and conventional continuous epidural block for management of zoster-associated pain beyond the acute phase: A retrospective study

Continuous epidural block (CEB) is a popular clinical method for controlling postherpetic neuralgia (PHN). However, the long-term effects of CEB on PHN have not yet been established. This study aimed to confirm the clinical efficacy of epidural electrical stimulation catheters in CEB to manage PHN.Patients were classified into 2 groups: those with subacute PHN, between 30 and 180 days after the onset of the rash; and those with chronic PHN, over 180 days after the onset of the rash. On the basis of the type of catheter used, the patients were further divided into the following 2 groups: the esopocan group, in which the site of herpes zoster infection was confirmed using a contrast medium alone; and the epistim group, in which an additional method of electrical stimulation through a guide-wire in the catheter was used for detecting the site affected by herpes. Clinical efficacy was assessed with a numerical rating scale immediately 1, 3, and 6 months after the procedure. We also investigated whether additional interventional treatment was necessitated because of insufficient pain control during the 6-month follow-up.We examined 88 patients. In the subacute PHN period, the numerical rating scale score was significantly lower in the epistim group than in the esopocan group until 6 months. In the chronic PHN period, no significant differences in the numerical rating scale scores were observed between the 2 groups until 6 months. In the subacute PHN period, the adjusted odds ratio for other interventional procedures within 6 months in the esopocan group versus the epistim group was 2.59 (95% confidence interval [CI] 0.83-8.09, P = .10), and in the chronic PHN period, it was 1.31 (95% CI 0.11-5.46, P = .79).Epidural drug administration to specific segments using electrical stimulation catheters may be more useful in mitigating zoster-associated pain in subacute PHN.

Short-term efficacy and safety of prednisone in herpes zoster and the effects on IL-6 and IL-10

Short-term efficacy and safety of prednisone in herpes zoster and the effect on IL-6 and IL-10 were investigated. A total of 125 patients (aged 40–70 years) with acute infective herpes zoster who were admitted to Daqing Oilfield General Hospital were selected and divided into 3 groups according to different treatment methods: low-dose (n=44), middle-dose (n=42) and high-dose (n=39) groups. The therapeutic effect, visual analogue scale (VAS) pain score, pain relieving and disappearing time, herpes stopping and disappearing time, incrustation and decrustation time, and incidence of adverse reactions in the three groups were recorded. The changes of IL-6 and IL-10 levels in the peripheral blood of patients before and after treatment were detected by enzyme-linked immunosorbent assay (ELISA) in order to analyze their relationship with pain degree and the time of symptom remission and subsidence. There were no significant differences in cure rate, significant effective rate, effective rate, ineffective rate and total effective rate among the three groups (P>0.05). The pain relieving and disappearing time in the middle-dose group were shorter than those in the low- and high-dose groups (P<0.05). The levels of IL-6 and IL-10 showed no statistical differences in the 3 groups before treatment (P>0.05). Pearson correlation analysis showed that IL-6 was positively correlated with VAS pain score, pain relieving and disappearing time, herpes stopping and disappearing time, incrustation and decrustation time (P<0.05), while IL-10 was negatively correlated with the above indicators (P<0.05). In conclusion, middle-dose prednisone has similar short-term efficacy to high-dose prednisone in the treatment of herpes zoster, but with lower complication and higher safety. IL-6 and IL-10 are closely related to the pain degree and the time of symptom remission and subsidence, which may provide a reference for clinical evaluation of the therapeutic effect of patients with herpes zoster.

Risk Evaluation for Acute Kidney Injury Induced by the Concomitant Use of Valacyclovir, Analgesics, and Renin-Angiotensin System Inhibitors: The Detection of Signals of Drug-Drug Interactions

Background: Drug-related acute kidney disease is a common side effect of valacyclovir (VACV) treatment. Although analgesics are frequently administered concomitantly with VACV to treat the pain of herpes zoster, the differences between nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen in relation to VACV-related acute kidney injury (AKI) are unclear. The risk for AKI with concomitant use of VACV and renin–angiotensin system (RAS) inhibitors that can cause AKI via a similar mechanism to NSAIDs is also unknown. We therefore evaluated the association between concomitant use of these drugs and VACV-related AKI, which was characterized according to the Japanese Adverse Drug Event Report (JADER) database.

Methods: We analyzed data from the JADER database, which is a spontaneous reporting system. The reporting odds ratio was used to evaluate the signals of AKI.

Results: A high proportion of VACV-related AKI cases occurred in summer. There was an increase in AKI signal in cases with concomitant use of VACV and NSAIDs, while no increase was detected in cases with concomitant use of VACV and acetaminophen. AKI events in cases with concomitant use of VACV and NSAIDs were more frequent in older and female patients and those with hypertension. Additionally, a signal increase for VACV-related AKI was observed with concomitant use of RAS inhibitors, with or without NSAIDs.

Conclusions: We identified a seasonal variation in VACV-related AKI. Additionally, our findings indicate that acetaminophen might represent a safer analgesic than NSAIDs with respect to VACV-related AKI. We also identified candidate risk factors for AKI with concomitant use of NSAIDs, such as older age, female sex, and hypertension. Although further studies are warranted, our findings highlight the need to consider concomitant drug use and seasonal factors that lead to urinary output loss so that VACV-related AKI can be avoided.