Review of current guidelines on the care of postherpetic neuralgia

The usage of a modified straight-leg raise neurodynamic test and hamstring flexibility for diagnosis of non-specific low back pain: A cross-sectional study

OBJECTIVES

The main purpose of this research study was to compare mean modified straight-leg raise test (mSLR) and hamstring muscle length (HL) between chronic non-specific low back pain (LBP) and healthy subjects to understand the possibility of neuropathic causes in LBP population as it may impact the diagnosis and treatment of LBP. Another purpose was to compare mean mSLR between those with lumbar nerve root impingement and those without as determine by magnetic resonance imaging (MRI).

METHODS

The design of the study is cross sectional and included 32 subjects with ages ranging from 18-50 years old. Clinical exam objective measures were collected such as patient questionnaires, somatosensory tests, HL range of motion, and a mSLR test, and were compared to the findings from a structural lumbar spine MRI.

RESULTS

There were no significant differences in mean HL angulation and mSLR angulation between LBP and healthy subjects (p>0.05). There was no significant difference in mean HL by impingement by versus no impingement (38.3±15.6 versus 44.8±9.4, p = 0.08, Cohen's d = 0.50). On the other hand, there was a significant difference in mean mSLR angulation by impingement (57.6.3±8.7 versus 63.8±11.6, p = 0.05, Cohen's d = 0.60).

CONCLUSIONS

The mSLR test was found to be associated with lumbar nerve root compression, regardless of the existence of radiating leg symptoms, and showed no association solely with the report of LBP. The findings highlight the diagnostic dilemma facing clinicians in patients with chronic nonspecific LBP with uncorrelated neuroanatomical image findings. Clinically, it may be necessary to reevaluate the common practice of exclusively using the mSLR test for patients with leg symptoms. This study may impact the way chronic LBP and neuropathic symptoms are diagnosed, potentially improving treatment methods, reducing persistent symptoms, and ultimately improving disabling effects.

Perceptions, Attitudes, Beliefs, and Practices Toward Traditional Chinese Medicine Therapies for Herpes Zoster: A Cross-Sectional Study of Healthcare Professionals

Introduction

Traditional Chinese medicine (TCM) holds great potential in promoting healing and relieving pain for herpes zoster (HZ) treatments. Evidence showed that both healthcare professionals' (HCPs) belief and knowledge influence their attitudes, which result in their expression and direct behavior. However, little is known in this area regarding TCM treatments for HZ. This study aimed to understand the HCPs' perceptions, attitudes, beliefs, and practices toward TCM and its services for HZ.

Methods

During July 2021 and October 2022, a cross-sectional study of HCPs querying demographics, perceptions, attitudes, beliefs, and practices toward TCM and TCM services for HZ was conducted. The frequency and percentage or mean and standard deviation were used to present categorical data and continuous data, respectively. A Chi-square analysis compared nurses' and doctors' views on TCM treatments for HZ.

Results

Out of 306 eligible respondents, 66.0% used TCM content in clinical practice less than 40% of the time. Respondents reported that there were three main advantages of TCM for HZ, including better crusting and healing, fewer side effects, and mitigating complications. A total of 41.3% (81/196) of the respondents who had cared for/treated HZ patients applied TCM treatments. The three factors most associated with referrals/providing TCM to patients were postherpetic neuralgia, early erythema or papules, and acute pain. Compared to nurses, doctors showed more endorsement of the efficacy and cost-effectiveness of TCM treatments for HZ patients.

Conclusion

The study found that most healthcare professionals in HZ had a favorable view of TCM, but lacked practical experience administering it to patients. Programs should be developed to provide evidence-based TCM treatments and encourage combining TCM with Western medicine for better patient care.

Peripheral Nerve Stimulation for a Refractory Case of Postherpetic Neuralgia in the Upper Limb: A Case Report

Postherpetic neuralgia (PHN) is a chronic neuropathic pain syndrome that is a direct consequence of the reactivation of varicella zoster virus (VZV). It manifests as neuropathic pain, which is pain that occurs because of dysfunction or damage of the nerves that carry sensations to the brain, and this typically persists for months to years after herpes zoster. Current conservative management for PHN includes a combination of topical agents (i.e., lidocaine and capsaicin) and systemic therapy (i.e., serotonin and norepinephrine reuptake inhibitors (SNRIs), gabapentin, pregabalin, and opioids). For refractory cases, with persistent intractable pain, more invasive interventional techniques can be used as pain-relieving measures to improve the patient's quality of life. This report presents a patient with upper limb PHN who responded to peripheral nerve stimulation (PNS) after he failed to obtain sufficient pain relief with conservative management.

[Electrical dorsal root ganglion stimulation (DRGS) for the treatment of refractory postherpetic neuralgia]

Postherpetic neuralgia (PHN) is a rare complication of herpes zoster characterized by prolonged and excruciating pain. Traditional treatments for PHN, such as analgesics, anticonvulsants and antidepressants, do not always bring the desired result. One promising alternative that is attracting the attention of the scientific community is dorsal root ganglion stimulation (DRGS). This method focuses on targeted and precise targeting of the source of pain, providing a new level of effectiveness in the treatment of PHN.

OBJECTIVE

A retrospective analysis of the technique and results of implantation of a permanent device for stimulating the spinal ganglia in patients with refractory PHN at the Burdenko Neurosurgical Center.

MATERIAL AND METHODS

The study was conducted in 7 patients (5 men, 2 women) with refractory PHN in the period from 2018 to 2020. The age of the patients ranged from 57 to 84 years (average age 74±8.4). All patients were implanted with Boston systems (Precision or Spectra versions). Stimulation parameters: pulse width - 120-210 μs, frequency - 30-130 Hz, amplitude at the lower limit of the appearance of paresthesia with the possibility of increasing with increased pain up to 5 mA. The position of the electrode depended on the location of the pain. All systems were implanted under X-ray guidance.

RESULTS

The duration of follow-up observation was more than 2.5 years. The average pain intensity one year after treatment was 3.42±2.45 points on the visual analogue scale (VAS) (a 62.3% decrease in intensity compared to baseline). In 3 (42.8%) patients, the result was characterized by us as «excellent» (intensity according to VAS decreased by 75% or more), in 1 (14.2%) - as «good» (intensity according to VAS decreased by 50-74%), in 1 (14.2%) - as «moderate» (VAS intensity decreased by 25-49% and in 2 (28.5%) as «unsatisfactory» (VAS intensity decreased by less than 25%, or postoperative complications occurred).

CONCLUSION

Given the complicated nature of PHN, the use of dorsal ganglion stimulation appears to be a promising and innovative treatment approach. Further research is needed to introduce this technique into clinical practice for the treatment of patients suffering from PHN.

Autologous Fat Grafting Is Not Superior to Placebo as Treatment of Postherpetic Neuralgia: A Double-Blind Randomized Clinical Trial

BACKGROUND

Postherpetic neuralgia (PHN) is a chronic pain syndrome occurring after a herpes zoster outbreak. While there is no effective treatment available today, autologous fat grafting has shown promise. This randomized controlled trial investigated the effectiveness of fat grafting as treatment for PHN compared with a sham treatment.

METHODS

A total of 46 participants with PHN were included. After liposuction under general anesthesia, participants were randomly assigned to receive either autologous fat grafting or saline injection to the area of pain. The primary outcomes were the average and maximum degree of pain measured on an 11-point numeric rating scale. Secondary outcomes were quality and degree of neuropathic pain (Neuropathic Pain Symptom Inventory) and quality of life (36-Item Short-Form Health Survey).

RESULTS

Forty-two participants completed follow-up of 6 months. For maximal degree of pain, a reduction of -1.1 ± 0.6 and -1.0 ± 0.5 mean change (±SE) on the numeric rating scale was observed in the intervention and control groups, respectively. For average degree of pain, the reduction was -1.2 ± 0.5 and -1.3 ± 0.4 in the intervention and control groups, respectively. The authors did not observe any significant changes in the neuropathic pain and quality-of-life parameters. For all measured outcomes, the differences between the groups were not statistically significant.

CONCLUSIONS

The authors did not find autologous fat grafting superior to a placebo when treating PHN of the skin. Given their results, they cannot recommend the routine use of this method to treat these pains.

CLINICAL RELEVANCE STATEMENT

Since autologous fat grafting was not proven to be more effective than a placebo in treating PHN, alternative treatment options should be explored. It is also essential to emphasize the importance of prophylactic vaccination against herpes zoster.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

CT-guided paravertebral injection of doxorubicin for treatment of postherpetic neuralgia: a database-based retrospective stratified study

Objective

This study explored the impact of different doeses of doxorubicin in CT-guided transvertebral foraminal injections for postherpetic neuralgia (PHN) treatment and the impact of 0.5% doxorubicin treatment on patients with different disease courses and lesion locations.

Methods

This retrospective study included 291 patients with PHN who received CT-guided doxorubicin injection at West China Hospital between April 2014 and February 2020.

Results

A total of 228 patients received 0.5% doxorubicin treatment and 63 received 0.33% doxorubicin. Both groups showed significantly improvement in visual analogue scale (VAS) and Brief Pain Inventory (BPI) scores. The 0.5% doxorubicin group demonstrated significant lower VAS scores at 6 and 12 months after surgery (all p < 0.001) and a significant lower score on the BPI at 6 and 12 months than the 0.33% doxorubicin group (all p < 0.05). Stratified analysis of 0.5% doxorubicin demonstrated a significant reduction in VAS score at 1 week, 3 months, 6 months, and 12 months after treatment compared to baseline (all p < 0.05) and significant improvements in BPI score after treatment compared to baseline (p < 0.05). The VAS score of the chest group was significant higher than facial, neck and upper limbs and abdomen groupsin groups 1 week after surgery (all p < 0.05). Various aspects of quality of life, including daily life, enjoyment of life, sleep, relationships, work, walking ability, and emotions, significantly decreased after surgery (p < 0.05). Especially in sleep duration, there was an increase in patients reporting intermediate sleep (4-7 h) and a proportion achieving a normal sleep duration of ≥7 h. And no significant differences of BPI were observed among different affected locations. The incidence of adverse events in the 0.5% doxorubicin group and 0.33% doxorubicin group was 8.78 and 6.34%, respectively.

Conclusion

CT-guided doxorubicin injection therapy has the potential to alleviate pain and enhance the quality of life in patients with PHN. Notably, the use of a 0.5% doxorubicin concentration yields more pronounced pain relief compared to a 0.33% concentration. While longer durations of PHN and specific affected sites may influence the response to treatment, the overall improvements in quality of life remain consistent.

Peripheral Nerve Stimulation of the Lesser Occipital and Greater Auricular Nerve for Post Herpetic Neuralgia in a Case of Ramsay Hunt Syndrome: Case Report

Background

Post-herpetic neuralgia (PHN) is a painful condition that presents after herpes zoster reactivation in the peripheral and central nervous system. When medical treatment fails, options are limited, and patients may suffer with chronic pain indefinitely.

Case Presentation

We present the case of a gentleman with a 3-year history of PHN in the distribution of the right lesser occipital and greater auricular nerves that failed to respond to medical treatment. He underwent a trial of neuromodulation, and post-operative pain scores improved by 80%, and at 60 days post-operatively his average pain score was 0 out of 10.

Conclusions

PNS is an effective and safe option for the treatment of chronic pain, and we present a report of successful treatment of PHN in a particularly difficult anatomic distribution. PNS of the lesser occipital and greater auricular nerves is a novel treatment for PHN and shows promise as an effective, safe therapy when other treatment fails.

Efficacy and Safety of SIKD1977 in Combination with Standard Treatment for Postherpetic Neuralgia: Study Protocol for a Double Blind, Placebo-Controlled, Randomized, Multicenter, Phase 2 Clinical Trial

Purpose

Postherpetic neuralgia (PHN) is the most common chronic complication of herpes zoster, associated with poor quality of life and increased patient and healthcare resource expenditure. This randomized controlled trial aims to evaluate the efficacy and safety of SIKD1977 (Sogeonjungtang) in combination with standard treatment and estimate an effective dose for treating PHN.

Patients and Methods

This is a protocol for a randomized, placebo-controlled, double-blind, multicenter trial. A total of 90 eligible participants with PHN will be recruited from three hospitals and randomly allocated to high-dose group, low-dose group, or placebo group in a 1:1:1 ratio. The trial will involve a 6-week oral administration of SIKD1977/placebo, and a 1-week follow-up period. The primary outcome will be the weekly average change in average daily pain score (ADPS) from baseline to the end of treatment. The secondary outcomes will include the weekly average changes in ADPS from baseline to week 2, 4, and 7, differences in Short-Form McGill Pain Questionnaire, Visual analogue scale, 5-level EuroQol-5 dimensions, Patient Global Impression of Change, and consumption of rescue drugs. All adverse events will be assessed during the trial.

Conclusion

This study will provide evidence for the efficacy and safety of SIKD1977, and an effective dose for PHN.

Trial Registration

This protocol has been registered in the Clinical Research Information Service with the identification code KCT0007939.

Patterns and Trends in Pharmacological Treatment for Outpatients with Postherpetic Neuralgia in Six Major Areas of China, 2015-2019

The aim of this study was to assess the patterns and trends of pharmacological treatment for outpatients with postherpetic neuralgia (PHN) in China in the period 2015-2019. Prescription data for outpatients with PHN were extracted from the database of the Hospital Prescription Analysis Program of China according to the inclusion criteria. The trends in yearly prescriptions and corresponding costs were analyzed and stratified by drug class and specific drugs. A total of 19,196 prescriptions from 49 hospitals in 6 major regions of China were included for analysis. The yearly prescriptions increased from 2534 in 2015 to 5676 in 2019 (p = 0.027), and the corresponding expenditures increased from CNY 898,618 in 2015 to CNY 2,466,238 in 2019 (p = 0.027). Gabapentin and pregabalin are the most commonly used drugs for PHN, and more than 30% of these two drugs were combined with mecobalamin. Opioids were the second most frequently prescribed drug class, and oxycodone accounted for the largest share of the cost. Topical drugs and TCAs are rarely used. The frequent use of pregabalin and gabapentin was in accordance with current guidelines; however, the use of oxycodone raised concerns about rationality and economic burden. The results of this study may benefit the allocation of medical resources and management for PHN in China and other countries.

Analgesic Treatment Approach for Postherpetic Neuralgia: A Narrative Review

Post-herpetic neuralgia (PHN) is an entity derived from peripheral nerve damage that occurs during the reactivation of the Varicella Zoster Virus (VZV), which manifests itself through pain with neuropathic characteristics. This can prove to be very difficult to manage in the chronic stages of disease reappearance. There currently exists a multitude of treatment alternatives for PHN, however, prevention through the early initiation of antiviral regimens is vital. There are various pharmacological options available, but it is important to individualize each patient to maximize efficacy and minimize adverse effects. Interventional procedures have become a cornerstone in difficult-to-manage cases, and have shown promising outcomes when used in a multimodal approach by experienced specialists. It is necessary to make an objective diagnosis of PHN and start early treatment. Additionally there is current evidence that vouches for interventional therapies as well as individualization, with a clear establishment of therapeutic objectives according to the needs of each patient.

Efficacy of different acupuncture therapies on postherpetic neuralgia: A Bayesian network meta-analysis

Background

Postherpetic neuralgia (PHN) is a common, complex, and refractory type of neuropathic pain. Several systematic reviews support the efficacy of acupuncture and related treatments for PHN. Nevertheless, the efficacy of various acupuncture-related treatments for PHN remains debatable.

Objective

We aimed to assess the efficacy and safety of acupuncture-related treatments for PHN, identify the most effective acupuncture-related treatments, and expound on the current inadequacies and prospects in the applications of acupuncture-related therapies.

Methods

We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, Web of Science, Google Scholar, four Chinese databases (China National Knowledge Infrastructure, China Biomedical, Chongqing VIP, and Wan Fang databases), clinical research registration platform (World Health Organization International Clinical Trial Registration platform, China Clinical Trial Registration Center) for relevant studies. We also examined previous meta-analyses; gray literature; and reference lists of the selected studies. We then evaluated the risk of bias in the included studies and performed a Bayesian multiple network meta-analysis.

Results

We included 29 randomized controlled trials comprising 1,973 patients, of which five studies showed a high risk of bias. The pairwise meta-analysis results revealed that the efficacy of all acupuncture-related treatments for pain relief related to PHN was significantly better than antiepileptics. The network meta-analysis results showed that pricking and cupping plus antiepileptics were the most effective treatment, followed by electroacupuncture (EA) plus antiepileptics for pain relief in patients with PHN. EA plus antiepileptics ranked the best regarding reduced Pittsburgh Sleep Quality Index (PSQI) and Self-Rating Depression Scale (SDS) scores in patients with PHN. No results were found regarding the total response rate or quality of life in this study. Acupuncture-related treatments showed a lower incidence of adverse events than that of antiepileptics.

Conclusion

Acupuncture-related therapies are potential treatment options for PHN and are safe. Pricking and cupping plus antiepileptics, are the most effective acupuncture-related techniques for pain relief, while EA plus antiepileptics is the best acupuncture-related technique for improving PHN-related insomnia and depression symptoms. However, owing to the limitations of this study, these conclusions should be cautiously interpreted, and future high-quality studies are needed.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021226422, identifier CRD42021226422.

Rodent models of postherpetic neuralgia: How far have we reached?

Background

Induced by varicella zoster virus (VZV), postherpetic neuralgia (PHN) is one of the common complications of herpes zoster (HZ) with refractory pain. Animal models play pivotal roles in disclosing the pain mechanisms and developing effective treatments. However, only a few rodent models focus on the VZV-associated pain and PHN.

Objective

To summarize the establishment and characteristics of popular PHN rodent models, thus offer bases for the selection and improvement of PHN models.

Design

In this review, we retrospect two promising PHN rodent models, VZV-induced PHN model and HSV1-induced PHN model in terms of pain-related evaluations, their contributions to PHN pathogenesis and pharmacology.

Results

Significant difference of two PHN models is the probability of virus proliferation; 2) Most commonly used pain evaluation of PHN model is mechanical allodynia, but pain-induced anxiety and other behaviours are worth noting; 3) From current PHN models, pain mechanisms involve changes in virus gene and host gene expression, neuroimmune-glia interactions and ion channels; 4) antiviral drugs and classical analgesics serve more on the acute stage of herpetic pain.

Conclusions

Different PHN models assessed by various pain evaluations combine to fulfil more comprehensive understanding of PHN.

Acupuncture therapies for postherpetic neuralgia: a protocol for a systematic review and Bayesian network meta-analysis

INTRODUCTION

Postherpetic neuralgia (PHN) is the most common sequela of herpes zoster, and it is often refractory to guideline-recommended treatments. Acupuncture therapy, a wildly applied complementary-alternative treatment, may help in the management of PHN. Diverse types of acupuncture therapy for PHN have been proposed, however, their comparative efficacies remain unclear. This study protocol plans to compare the efficacy and safety of different acupuncture therapies for PHN.

METHODS AND ANALYSIS

Databases including MEDLINE, Embase, Cochrane Library, Web of Science, Chinese Biomedical Database, China National Knowledge Infrastructure, VIP Database, Wanfang Database, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, Chinese Clinical Trial Register and OpenGrey will be searched from their inception to January 2022. Randomised controlled trials (RCTs) assessing the effectiveness of acupuncture therapy on the management of PHN will be selected. The primary outcome is pain intensity. Secondary outcomes include negative emotions, sleep condition, quality of life and adverse events. Reviewers will conduct study selection, data extraction and risk of bias assessment procedures. Then, standard pair-wised meta-analysis and Bayesian network meta-analysis will be performed (if applicable). The Confidence in Network Meta-Analysis application will be used to assess the confidence in the evidence for the primary outcome.

ETHICS AND DISSEMINATION

All data used for this study will be extracted from published RCTs, thus, no ethical approval will be required. The results of this systematic review will be disseminated through peer-reviewed journal and conference presentation.

PROSPERO REGISTRATION NUMBER

CRD42020219576.

Computed Tomography-Guided Radiofrequency Ablation of the Cervical Dorsal Root Ganglia in 27 Patients with Cervical and Occipital Postherpetic Neuralgia

Background

Postherpetic neuralgia (PHN) is a common complication of herpes zoster virus infection that is associated with intense pain. The present study aimed to investigate the use of computed tomography (CT)-guided radiofrequency ablation (RFA) of the cervical dorsal root ganglia (DRG) for treatment of cervical and occipital PHN in 27 patients at a single center.

Material/Methods

Twenty-seven patients with PHN in the cervical and/or occipital region were enrolled. After imaging the area of PHN in the patients, axial scanning was performed on the upper cervical segment in the spinal scanning mode. The puncture path was defined and then RFA therapy (90°C for 180 s) was performed by targeting the corresponding intervertebral foramen. Patients were followed 2 days later and at 1, 3, 6, and 12 months after surgery. Observation at each follow-up visit included rating of pain on a visual analog scale (VAS) and assessment of complications and adverse events.

Results

VAS scores significantly decreased in patients with PHN after RFA compared with their scores before RFA (P<0.05). Skin sensation decreased in the area that was originally painful and allodynia significantly diminished.

Conclusions

The findings from this small study from a single center showed that CT-guided percutaneous RFA of cervical DRG safely and effectively reduced cervical and occipital PHN in the short term.

Retrospective Analysis of 170 Patients Followed up with Herpes Zoster and Postherpetic Neuralgia in Nothern Cyprus

Herpes zoster is viral infection that occurs with reactivation of the varicella-zoster virus (VZV). It is usually a painful but self-limited dermatomal rash with  cutaneous distribution. Although it's usually a painful, self-limiting rash, it can be much more serious; In addition, acute cases often lead to postherpetic neuralgia (PHN) and seriously impair quality of life. It is important to recognize those at risk of developing postherpetic neuralgia, early treatment and prevent complications. Objectives :Our aim is to determine the clinical features of our herpes zoster diseases and to review the treatments in patients with postherpetic neuralgia. Methods: A search for HZ and PHN was conducted in a general practice research database, comprising 2 general practices( dermatologist and physatrist) and representing 5600 people. We analyzed a retrospective 170 case series of pediatirc and adults addmited  to the dermatology and physical therapy and rehabilitation outpatient clinic between October 2018 and October 2020. Results: A total of 170 new cases had been diagnosed with HZ in the dermatology and physical therapy and rehabilitation clinics over 2 years . Female to male ratio was 2:1 and the age ranged from 5 years to 88 years. The thoracic dermatomes were the most commonly involved. The risk of developing PHN 1 month after the start of the zoster rash was 21 %. Independent risk indicators for the occurrence of PHN were age [55–74] years. Conclusion : The risk of developing PHN increases with age and with commorbitity. Preventive strategies such as vaccination should focus on patients with herpes zoster aged >55 years.

Nonprescription Products of Internet Retailers for the Prevention and Management of Herpes Zoster and Postherpetic Neuralgia: Analysis of Consumer Reviews on Amazon

BACKGROUND

Herpes zoster affects approximately 1 million people annually in the United States, with postherpetic neuralgia as the most common complication. The frequent prescription of opioids as the first-line medication for herpes zoster or postherpetic neuralgia contributes to the increasing health care costs of their treatment. Despite the advent of internet retailers providing alternative products for the prevention and management these conditions, there are limited studies on the availability, ingredients, and consumer preference for the products.

OBJECTIVE

This study used the internet retailer Amazon to determine the availability of products for the management of herpes zoster and postherpetic neuralgia, and assessed consumer preference based on listed ingredients.

METHODS

The internet retailer Amazon was used to perform a search for products related to "shingles" in September 2020. Top products sorted by reviews and ratings were determined to be either shingles-specific (including "shingles" in either the product title or description) or shingles-nonspecific. Analysis of price, rating, type of vehicle, and ingredients was performed. The types of vehicles, ingredients, and percentages of positive and negative reviews related to "shingles" of the product groups were analyzed with a two-tailed two-sample proportions Z-test to assess the difference between shingles-specific and shingles-nonspecific products. Statistical significance was judged at P<.05.

RESULTS

The top 131 products among over 3000 products retrieved were determined based on a rating of 4 or more stars after searching for the term "shingles" on Amazon. Forty-six of the 131 products (35.1%) were shingles-specific. Shingles-nonspecific products were more likely to have positive reviews mentioning "shingles" (P=.005). Vehicles, balms (P=.02), and salves (P=.04) were more likely to be shingles-specific, whereas tablets or capsules (P=.002) were more likely to be shingles-nonspecific. Among the ingredients analyzed, aloe vera was the top-ranked ingredient, included in 29 of the 131 total products (22.1%). Aloe vera (P=.01), lemon balm (P<.001), vitamin E (P=.03), and peppermint oil (P=.008) were more likely to be included in the shingles-specific products, whereas magnesium (P=.01) was more likely to be included in shingles-nonspecific products.

CONCLUSIONS

There is an abundance of products and ingredients being used for the management and treatment of shingles with certain ingredients preferred by consumers. There is a discrepancy between approved ingredients and the ingredients preferred by consumers. Furthermore, there are insufficient studies on ingredients used by consumers on internet retailers such as Amazon, and future studies can focus on the effectiveness of popular ingredients to decrease misinformation on the internet.

A fixed nitrous oxide/oxygen mixture as an analgesic for patients with postherpetic neuralgia: study protocol for a randomized controlled trial

BACKGROUND

The pain management of postherpetic neuralgia (PHN) remains a major challenge, with no immediate relief. Nitrous oxide/oxygen mixture has the advantages of quick analgesic effect and well-tolerated. The purpose of this study is to investigate the analgesic effect and safety of nitrous oxide/oxygen mixture in patients with PHN.

METHODS/DESIGN

This study is a single-center, two-group (1:1), randomized, placebo-controlled, double-blind clinical trial. A total of 42 patients with postherpetic neuralgia will be recruited and randomly divided into the intervention group and the control group. The control group will receive routine treatment plus oxygen, and the intervention group will receive routine treatment plus nitrous oxide/oxygen mixture. Data collectors, patients, and clinicians are all blind to the therapy. The outcomes of each group will be monitored at baseline (T0), 5 min (T1), and 15 min (T2) after the start of the therapy and at 5 min after the end of the therapy (T3). The primary outcome measure will be the pain intensity. Secondary outcomes included physiological parameters, adverse effects, patients' acceptance of analgesia, and satisfaction from patients.

DISCUSSION

Previous studies have shown that nitrous oxide/oxygen mixture can effectively relieve cancer patients with breakthrough pain. This study will explore the analgesic effect of oxide/oxygen mixture on PHN. If beneficial to patients with PHN, it will contribute to the pain management of PHN.

TRIAL REGISTRATION

Chinese Clinical Trial Register ChiCTR1900023730 . Registered on 9 June 2019.

CT-Guided Pulsed Radiofrequency at Different Voltages in the Treatment of Postherpetic Neuralgia

Background

Postherpetic neuralgia (PHN) is a form of long-lasting neuropathic pain that can severely affect patients’ quality of life. Pulsed radiofrequency (PRF) has been proven to be effective in treating PHN, but the optimal radiofrequency parameters are still not well defined. This retrospective study aimed to compare the efficacy and safety of CT-guided PRF at three different voltages for the treatment of PHN patients.

Methods

This study included 109 patients with PHN involving the thoracic dermatome who were treated in the Department of Pain Management of Shengjing Hospital, China Medical University, from January 2017 to May 2019. They were divided into three groups based on the PRF voltage used: group A (45 V), group B (55 V), and group C (65 V). The PRF therapy (voltage 45, 55, and 65 V) was performed in all patients by targeting the thoracic dorsal root ganglion. After surgery, patients were followed at 3 days, 1 month, 3 months, 6 months, and 12 months. Observation at each follow-up included basic patient characteristics, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36) scores, patient satisfaction, complications, and side effects.

Results

Visual analog scale scores decreased and SF-36 scores increased for all patients in the three groups at each post-operative time point (1, 3, 6, and 12 months; all P < 0.01). Pain relief, improvement in quality of life, and overall satisfaction were more significant for patients in group C than for those in groups A and B at the 3-, 6-, and 12-month follow-ups (all P < 0.05). Patients in group B had lower VAS scores and higher overall satisfaction levels than those in group A (both P < 0.01). A small number of patients from each group (n ≤ 3) experienced mild intraoperative and post-operative complications, which bore no relationship with group assignment (all P > 0.05). At post-operative day 3, patients in group C had skin numbness affecting a larger area than patients in the other two groups (both P < 0.05), but the differences were no longer statistically significant at day 30 after the operation. All patients experienced a drop in numbness area of more than 30% after surgery.

Conclusion

Compared with PFR at 45 and 55 V, PFR at 65 V had superior efficacy in treating PNH, with a favorable safety profile.

[Manifestations of herpes zoster ophthalmicus]

The article reviews the main ocular features of Herpes Zoster Ophthalmicus (HZO) including Ramsay-Hunt and Tolosa-Hunt syndromes that involve III, IV and VI pairs of cranial nerves and I branch of the trigeminal nerve, and describes treatment methods of its active manifestations and postherpetic neuralgia, as well as herpes zoster vaccination practices.

Patterns of anticonvulsant use and adverse drug events in older adults

PURPOSE

To examine indications for, duration of use, and rate of adverse drug events (ADE) attributable to anticonvulsant initiation, as adjudicated by expert review of electronic health records (EHR) of older adults.

METHODS

We identified a cohort of community dwelling Medicare beneficiaries with linked EHR (aged 65+, continuously enrolled with a large health system/until death between 2012 and 2014, n = 20 945) and drew a stratified EHR review sample (n = 1534). An expert reviewed all records to adjudicate anticonvulsant use, years of use, indication for use, and evidence of ADEs attributable to anticonvulsant initiation. After excluding patients with insufficient EHR data (n = 37; 2%), we reconstructed the cohort using inverse probability weights to resemble the original cohort of eligible beneficiaries (n = 20 380). Among incident users of a single anticonvulsant, we estimated the rate of ADEs and described the type and severity of ADEs.

RESULTS

Overall, 12% (n = 2469) of eligible beneficiaries used at least one anticonvulsant in the 2012 to 2014 period (4% [n = 757] incident users, 8% [n = 1712] prevalent users). Incident users were most frequently prescribed gabapentin (n = 461/757, 61%), benzodiazepines (n = 122/757, 16%), and levetiracetam (n = 74/757, 10%); the most common indication was pain relief (n = 214; 28%) followed by epilepsy (n = 53; 7%). Among incident users, the overall ADE rate was 10/100 person-years (95% CI 4-20/100 person-years), of which 29% (n = 28/97) were life threatening (eg, somnolence). Most ADEs among incident monotherapy users were nervous system related (68%, n = 66/97).

CONCLUSION

Many older adult community dwelling traditional Medicare beneficiaries had clinically significant ADEs likely attributable to the initiation of anticonvulsant therapy, which was begun for a range of indications.

Herpes Zoster and Postherpetic Neuralgia in an Elderly Patient with Critical COVID-19: A Case Report

Critical patients with COVID-19 are thought to be at high risk of developing chronic pain. However, the exact nature and mechanisms of COVID-19-related chronic pain remain largely unknown. Here, we describe clinical features, treatments and outcome of herpes zoster as well as postherpetic neuralgia in a 70-year-old woman with critical COVID-19. The patient had a history of type 2 diabetes and myasthenia gravis. She developed herpes zoster in the right 10 to 12 lumbar dermatomes in the recovery period of COVID-19. Intravenous (250 mg 3 times a day) and then oral (400 mg 5 times a day) acyclovir was used for antiviral therapy. Pregabalin (75 mg orally twice a day) and ibuprofen was used for analgesia. Her skin lesions resolved 21 days after the onset of rash. However, she continued to have persistent pain in the same dermatomal distribution. After the dosage of pregabalin was increased to 150 mg orally twice a day, her pain was partially relieved. During the telephone follow-up 4 months after herpes zoster eruption, the patient still complained intermittent pain in the right 10 to 12 lumbar dermatomes. Our case draws attention to postherpetic neuralgia in COVID-19 patients and provides a targeted suggestion for this kind of patients.

Postherpetic neuralgia and recalcitrant cystic lesions following herpes zoster: A case report and review of treatment options

Acute herpes zoster lesions in most cases are self-limited except in older and immunocompromised patients, wherein the pain can cause significant suffering. Postherpetic neuralgia is a painful situation for patients that can compromise the quality of life. Here, we report a 30-year-old healthy young man who developed treatment-resistant postherpetic neuralgia after herpes zoster (fourth/fifth thoracic segment) without any underlying immunocompromised state. He also developed some cystic lesions, which were removed by aspiration and surgery. The skin lesions improved 2 weeks after the surgery and postherpetic neuralgia was completely cured after 5 months, however cystic lesions recurred multiple times and were excised completely during each visit. Postherpetic neuralgia has a significant impact on the health-care cost borne by the society and affected individual, hence, it is essential to select appropriate treatment to manage the pain of postherpetic neuralgia.

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.

Herpes Zoster Presentation, Management, and Prevention: A Modern Case-Based Review

Herpes zoster (HZ) is a common cutaneous entity with protean clinical presentations, management options, complication rates, and prevention strategies, all of which are rife with dogma. During an inpatient consultation for HZ, have you ever been approached by a frantic staff or family member, worried that a pregnant, elderly, or infant contact will be 'infected' if they get too close? Have your patients ever asked you about their risk of having HZ twice, or claimed that they have frequent 'recurrences'? In what timeline should antiviral therapy be employed? Is there evidence for prednisone or gabapentin in acute HZ treatment? Who should be vaccinated against HZ and what are the benefits and risks? In case-based form, these and other complex but common scenarios will be examined using clinical and viral mechanistic clues, along with updated treatment and prevention guidelines, to provide a modern HZ case management compendium, comprehensive of the diverse age and health populations now presenting with this condition.

Treatment Patterns and Medication Use in Patients with Postherpetic Neuralgia

BACKGROUND

Postherpetic neuralgia (PHN) is a chronic, painful condition characterized by persistent pain following resolution of a herpes zoster (HZ) infection. Epidemiologic data demonstrate that the risks for HZ infections and the development of PHN increase with age.

OBJECTIVE

To characterize prescribing patterns, health care utilization, and treatment costs for adults with PHN based on real-world data.

METHODS

This study analyzed medical and pharmacy claims from 2010 to 2014 in the MarketScan Commercial and Medicare Supplemental databases. PHN patients were identified based on criteria from a published algorithm. PHN treatment patterns were analyzed by age and reported descriptively for patients aged < 65 or ≥ 65 years. Excess incremental health care costs were calculated for PHN patients by comparing expenditures for a cohort of PHN patients to expenditures of a propensity score-matched control group of patients with HZ alone.

RESULTS

Approximately 0.4% of patients aged < 65 years were diagnosed with HZ versus 1.3% of patients aged ≥ 65 years; approximately 15.3% of HZ patients aged < 65 years and 26.4% of patients aged ≥ 65 years were diagnosed with PHN. Overall, opioids remained the most frequently prescribed initial treatment. Approximately 21.6% of PHN patients received an opioid as an initial treatment for PHN, 15.1% received gabapentin; 8.9% received a prescription nonsteroidal anti-inflammatory drug (NSAID); 8.3% received a lidocaine patch; 3.3% received pregabalin; 2.5% received a tricyclic antidepressants (TCAs); 0.8% received other topical lidocaine; and < 1% received capsaicin. Observed first-line use of the lidocaine patch and gabapentin was higher in patients aged ≥ 65 years relative to patients aged < 65 years. When separated by age group, only 24.6% of patients aged < 65 years and 38.5% of patients aged ≥ 65 years were prescribed a recommended first-line treatment for initial PHN therapy (gabapentin, lidocaine patch, pregabalin, and TCAs). Comparisons of treatment costs of PHN patients to matched HZ patients without PHN indicated that PHN patients initiated on opioids had the highest mean additional health care expenditure compared with PHN patients initiated on other medications. On average, PHN patients initiated on opioids had $7,601 additional health care expenditure compared with HZ patients with no PHN; additional expenditures were $6,428 for pregabalin, $4,213 for lidocaine patches, $3,478 for gabapentin, $3,304 for NSAIDs, and $2,797 for TCAs, respectively.

CONCLUSIONS

Management of PHN is associated with substantial utilization of opioid-based therapies across all ages. Medications supported by evidence either as first-line therapies or as part of a multimodal regimen for the management of PHN are underused relative to opioid-based PHN therapies. Improving adherence to evidence-based PHN treatment regimens offers the potential to reduce opioid prescribing first line and reduce overall treatment costs. Given the emphasis to reduce opioid prescribing to minimize the risk of dependence, abuse, and diversion, multimodal analgesic treatments that can avoid or reduce opioid use should be considered.

DISCLOSURES

Research funding was provided by SCILEX Pharmaceuticals. The sponsor reviewed and approved the research plan and provided support for manuscript preparation through Patel's role as a coauthor of this manuscript. The sponsor's product (lidocaine patch) was not used in this study. Patel is a paid employee of SCILEX Pharmaceuticals. Goss is an employee and minority owner of Boston Healthcare Associates, which received a research grant from SCILEX Pharmaceuticals to conduct this study. Gudin reports advisory board fees from AcelRx Pharmaceuticals and BioDelivery Sciences International and consulting fees from Averitas, Daiichi, Hisumitsu, Nektar, Purdue, Quest Diagnostics, SCILEX Pharmaceuticals, and US WorldMeds, unrelated to this study. Fudin reports advisory board fees from AcelRx Pharmaceuticals, Human Half-Cell, Quest Diagnostics, GlaxoSmithKline, SCILEX Pharmaceuticals, BioDelivery Sciences, Daiichi Sankyo, and Salix Pharmaceuticals; speaker fees from Daiichi Sankyo, Salix Pharmaceuticals, Abbott Laboratories, Acutis Diagnostics, and AstraZeneca; and consulting fees from Firstox Laboratories, unrelated to this study. The other authors have nothing to disclose. Parts of this research were presented at the AMCP Managed Care & Specialty Pharmacy Annual Meeting; April 22, 2016; San Francisco, CA, and at the 35th Annual Scientific Meeting of the American Pain Society; May 11-14, 2016; Austin, TX.

Patient and economic burdens of postherpetic neuralgia in China

Background

Little is known about the patient-reported and economic burdens of postherpetic neuralgia (PHN) among China’s urban population.

Methods

This noninterventional study was conducted among adults ≥40 years with PHN who were seeking medical care at eight urban hospitals in China. At one study site, patients completed a questionnaire evaluating the patient-reported disease burden (N=185). The questionnaire consisted of validated patient-reported outcomes including the Brief Pain Inventory (BPI), 5-dimension, 3-level EuroQol (EQ-5D-3L), Medical Outcomes Study Sleep Scale, and Work Productivity and Activity Impairment Questionnaire for Specific Health Problems. Questions on non-pharmacologic therapy and out-of-pocket (OOP) expenses were also included. At all study sites, physicians (N=100) completed a structured review of patient charts (N=828), which was used to derive health care resource utilization and associated costs from the societal perspective. Annual costs in Chinese Yuan Renminbi (RMB) for the year 2016 were converted to US dollars (US$).

Results

Patients (N=185, mean age 63.0 years, 53.5% female) reported pain of moderate severity (mean BPI score 4.6); poor sleep quantity (average of 5.3 hrs per night) and quality; and poorer health status on the EQ-5D-3L relative to the general Chinese population. Respondents also reported average annual OOP costs of RMB 16,873 (US$2541) per patient, mainly for prescription PHN medications (RMB 8990 [US$1354]). Substantial work impairment among employed individuals resulted in annual indirect costs of RMB 28,025 (US$4221). In the chart review, physicians reported that patients (N=828) had substantial health resource utilization, especially office visits; 98% had all-cause and 95% had PHN-related office visits. Total annual direct medical costs were RMB 10,002 (US$1507), mostly driven by hospitalizations (RMB 8781 [US$1323]).

Conclusion

In urban China, PHN is associated with a patient-reported burden, affecting sleep, quality-of-life, and daily activities including work impairment, and an economic burden resulting from direct medical costs and indirect costs due to lost productivity. These burdens suggest the need for appropriate prevention and management of PHN.

Assessing the reporting quality in randomized controlled trials of acupuncture for postherpetic neuralgia using the CONSORT statement and STRICTA guidelines

Background

This study evaluates the reporting quality of randomized controlled trials (RCTs) on acupuncture use for the treatment of postherpetic neuralgia and explores related factors.

Methods

The following six databases PubMed, Embase, Cochrane Library, VIP, CNKI, and SinoMed, were systematically searched from their inception to December 2018. RCTs using acupuncture as an intervention for postherpetic neuralgia were selected and incorporated in this study. The reporting quality was assessed based on the CONSORT statement and the STRICTA guidelines. Regression analyses were also conducted on pre-specified study characteristics searching for factors associated with reporting quality.

Results

A total of 137 RCTs were included in this study. The CONSORT based median OQS was 12 (minimum 3, maximum 29). Of the items comprised in the statement, ten were sufficiently reported (reported in over 70% of trials). The remaining fifty-five items were poorly reported (reported by fewer than 5% of trials). The STRICTA based median OQS was 9 (minimum 2, maximum 15). The results showed that eight of the comprised items were well reported (reported in over 70% of trials), and only three were incompletely reported (reported in fewer than 20% of trials). Based on the CONSORT statement related analysis, a post-2010 publication (β coefficient 2.394, 95% confidence interval [CI] 1.168–3.620) and funding (β coefficient 4.456, 95% CI: 3.009–5.903) represented independent and significant predictors of a high overall reporting quality. However, only a funding source (β coefficient 1.305, 95% CI 0.219–2.391) was associated with an increased OQS based on STRICTA analysis.

Conclusion

The findings indicated that RCTs on acupuncture for PHN generally had a sub-optimal reporting quality, a situation that improved for those published after 2010 or with funding sources. Therefore, rigorous adherence to the CONSORT statement and the STRICTA guidelines should be emphasized in future studies.

The Use of Opioids for Treatment of Pediatric Neuropathic Pain: A Literature Review

Pediatric neuropathic pain is caused by a spectrum of disorders that are generally challenging to treat. Many of the underlying altered neurological processes are being elucidated through mechanistic studies. Few randomized control trials have evaluated the use of opioids for the treatment of adult neuropathic pain conditions, and there have been none in pediatric populations. With sparse data to provide guidance and an incomplete understanding of the underlying mechanisms, the use of opioids remains unclear. Our clinical experience and typical risk versus benefit considerations suggest a limited, if any, role for using opioids to treat pediatric neuropathic pain. In this literature review, we review the available adult and pediatric data and provide general guidance on this subject matter.

Coping with Phantom Limb Pain

Phantom limb pain is a chronic neuropathic pain that develops in 45-85% of patients who undergo major amputations of the upper and lower extremities and appears predominantly during two time frames following an amputation: the first month and later about 1 year. Although in most patients the frequency and intensity of pain diminish over time, severe pain persists in about 5-10%. It has been proposed that factors in both the peripheral and central nervous systems play major roles in triggering the development and maintenance of pain associated with extremity amputations. Chronic pain is physically and mentally debilitating, affecting an individual's capacity for self-care, but also diminishing an individual's daily capacity for personal and economic independence. In addition, the pain may lead to depression and feelings of hopelessness. A National Center for Biotechnology Information study found that in the USA alone, the annual cost of dealing with neuropathic pain is more than $600 billion, with an estimated 20 million people in the USA suffering from this condition. Although the pain can be reduced by antiepileptic drugs and analgesics, they are frequently ineffective or their side effects preclude their use. The optimal approach for eliminating neuropathic pain and improving individuals' quality of life is the development of novel techniques that permanently prevent the development and maintenance of neuropathic pain, or that eliminate the pain once it has developed. What is still required is understanding when and where an effective novel technique must be applied, such as onto the nerve stump of the transected peripheral axons, dorsal root ganglion neurons, spinal cord, or cortex to induce the desired influences. This review, the second of two in this journal volume, examines the techniques that may be capable of reducing or eliminating chronic neuropathic pain once it has developed. Such an understanding will improve amputees' quality of life by blocking the mechanisms that trigger and/or maintain PLP and chronic neuropathic pain.

Acupuncture for postherpetic neuralgia: Systematic review and meta-analysis

BACKGROUND

Acupuncture is widely used for postherpetic neuralgia (PHN) in China but its effect is unclear. We aim to evaluate the effect and safety of acupuncture for PHN.

METHODS

The Cochrane Skin Group Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, and the gray literature were searched. Randomized controlled trials (RCTs) comparing acupuncture alone versus no treatment/another active therapy/sham acupuncture, or comparing acupuncture with another active therapy versus the same active therapy were included.

RESULTS

Seven RCTs comparing acupuncture versus pharmacologic therapy were included. Meta-analysis was conducted for acupuncture's effect on PHN evaluating by pain intensity. Results from 2 RCTs showed that compared with pharmacologic therapy, acupuncture was better in decreasing the pain intensity measured by visual analog scale score (mean difference: 1.80, 95% confidence interval 1.72-1.87; P < .001). The limitations of the study are as follows: only trials comparing acupuncture versus pharmacologic therapy were included and all of the included trials were performed in China.

CONCLUSION

There was not enough evidence to suggest that acupuncture was superior to pharmacologic therapy in improving global impression or life quality. No adverse effects about acupuncture were reported. In all, acupuncture is safe and might be effective in pain relieving for patients with PHN. Given the low quality of included studies, the results are not conclusive and more large-scale RCTs with high quality are needed.

Neuropathic Corneal Pain: Approaches for Management

Neuropathic pain is caused by a primary lesion or dysfunction of the nervous system and can occur in the cornea. However, neuropathic corneal pain (NCP) is currently an ill-defined disease. Patients with NCP are extremely challenging to manage, and evidence-based clinical recommendations for the management of patients with NCP are scarce. The objectives of this review are to provide guidelines for diagnosis and treatment of patients with NCP and to summarize current evidence-based literature in this area. We performed a systematic literature search of all relevant publications between 1966 and 2017. Treatment recommendations are, in part, based on methodologically sound randomized controlled trials (RCTs), demonstrating superiority to placebo or relevant control treatments, and on the consistency of evidence, degree of efficacy, and safety. In addition, the recommendations include our own extensive experience in the management of these patients over the past decade. A comprehensive algorithm, based on clinical evaluation and complementary tests, is presented for diagnosis and subcategorization of patients with NCP. Recommended first-line topical treatments include neuroregenerative and anti-inflammatory agents, and first-line systemic pharmacotherapy includes tricyclic antidepressants and an anticonvulsant. Second-line oral treatments recommended include an opioid-antagonist and opiate analgesics. Complementary and alternative treatments, such as cardiovascular exercise, acupuncture, omega-3 fatty acid supplementation, and gluten-free diet, may have additional benefits, as do potential noninvasive and invasive procedures in recalcitrant cases. Medication selection should be tailored on an individual basis, considering side effects, comorbidities, and levels of peripheral and centralized pain. Nevertheless, there is an urgent need for long-term studies and RCTs assessing the efficacy of treatments for NCP.

Comparing serum microRNA levels of acute herpes zoster patients with those of postherpetic neuralgia patients

Postherpetic neuralgia (PHN) is commonly defined as pain persisting for at least 3 months after acute herpes zoster (AHZ) rash presentation. About one-tenth of all acute herpes zoster patients develop PHN. Circulating microRNAs (miRNAs) are promising biomarkers for infectious diseases; however, there has been no relationship established between circulating miRNAs and PHN to date; the aim of the present investigation was to elucidate this relationship.We compared serum levels of miRNA in PHN and AHZ patients. Twenty-nine patients with PHN and 37 patients with AHZ participated. MiRNA serum levels were determined via TaqMan Low Density Array (TLDA) and confirmed individually by RT-qPCR.TLDA results showed that the expression levels of 157 serum miRNAs in PHN patients were distinct from those in AHZ patients. Among these PHN patient serum miRNAs, 17 were upregulated and 139 were downregulated in contrast to those in AHZ patients. Receiver operational characteristic (ROC) curve analysis and RT-qPCR results altogether confirmed that the levels of miR-34c-5p, miR-107, miR-892b, miR-486-3p, and miR-127-5p were notably increased in PHN patients in comparison with those of AHZ patients. These miRNAs in circulation may regulate numerous relevant pathways. A few likely participate in the nervous system and inflammatory reactions.This study is the first to show that the expression profiles of numerous miRNAs vary in the PHN process. Among these, 5 types of serum miRNAs are very likely related to PHN development.

The Effectiveness and Safety of Topical Capsaicin in Postherpetic Neuralgia: A Systematic Review and Meta-analysis

In particular, neuropathic pain is a major form of chronic pain. This type of pain results from dysfunction or lesions in the central and peripheral nervous system. Capsaicin has been traditionally utilized as a medicine to remedy pain. However, the effectiveness and safety of this practice is still elusive. Therefore, this systematic review aimed to investigate the effect of topical capsaicin as a pain-relieving agent that is frequently used in pain management. In brief, all the double-blinded, randomized placebo- or vehicle-controlled trials that were published in English addressing postherpetic neuralgia were included. Meta-analysis was performed using Revman^® version 5.3. Upon application of the inclusion and exclusion criteria, only six trials fulfilled all the criteria and were included in the review for qualitative analysis. The difference in mean percentage change in numeric pain rating scale score ranges from -31 to -4.3. This demonstrated high efficacy of topical capsaicin application and implies that capsaicin could result in pain reduction. Furthermore, meta-analysis was performed on five of the included studies. All the results of studies are in favor of the treatment using capsaicin. The incidence of side effects from using topical capsaicin is consistently higher in all included studies, but the significance of safety data cannot be quantified due to a lack of p-values in the original studies. Nevertheless, topical capsaicin is a promising treatment option for specific patient groups or certain neuropathic pain conditions such as postherpetic neuralgia.

Postherpetic neuralgia: epidemiology, pathophysiology, and pain management pharmacology

Herpes zoster, also known as shingles, is a distinctive clinical condition caused by the reactivation of latent varicella zoster (chickenpox) virus following an initial infection. Approximately 1 million cases of herpes zoster occur annually in the US, and one in every three people develops herpes zoster during their lifetime. Postherpetic neuralgia is a neuropathic pain syndrome characterized by pain that persists for months to years after resolution of the herpes zoster rash. It stems from damage to peripheral and central neurons that may be a byproduct of the immune/inflammatory response accompanying varicella zoster virus reactivation. Patients with postherpetic neuralgia report decreased quality of life and interference with activities of daily living. Approaches to management of postherpetic neuralgia include preventing herpes zoster through vaccination and/or antiviral treatment, and administering specific medications to treat pain. Current guidelines recommend treatment of postherpetic neuralgia in a hierarchical manner, with calcium channel α2-δ ligands (gabapentin and pregabalin), tricyclic antidepressants (amitriptyline, nortriptyline, or desipramine), or topical lidocaine patches as first-line drugs. The safety and tolerability of pharmacologic therapies for pain are important issues to consider as postherpetic neuralgia affects primarily an older population. Patients should be educated on appropriate dosing, titration if applicable, the importance of adherence to treatment for optimal effectiveness, and possible side effects. Health-care professionals play a key role in helping to ameliorate the pain caused by postherpetic neuralgia through early recognition and diligent assessment of the problem; recommending evidence-based treatments; and monitoring treatment adherence, adverse events, responses, and expectations. Nurse practitioners are especially crucial in establishing communication with patients and encouraging the initiation of appropriate pain-relieving treatments.

Relationships Among Adverse Events, Disease Characteristics, and Demographics in Treatment of Postherpetic Neuralgia With Gastroretentive Gabapentin

Objectives:

To characterize risk factors for occurrence of adverse events (AEs) and treatment discontinuations due to AEs for improving safety and tolerability of treatment of postherpetic neuralgia (PHN).

Methods:

Patients with PHN (n=556) received 1800 mg once-daily gastroretentive gabapentin (G-GR) in 2 phase 3 and 1 phase 4 study. Safety assessments included the incidence and severity of AEs and analysis of discontinuations due to AEs. Multivariable, logistic regression analyses examined predictors of AE reporting and discontinuations due to AEs.

Results:

In total, 53.2% of patients reported any AE, and 12.9% discontinued because of AEs. Both AE incidence and treatment discontinuations decreased rapidly during the 2-week titration to sustained, low levels. The probability to report any AE was 0.6 for females versus 0.4 for males, whereas there were no differences in probabilities for age (less than 75 vs. 75 y and older) and race (nonwhite vs. white). Consistent with this, only female sex was a significant (P=0.0006) predictor of AE reporting. Experiencing moderate (P≤0.0001) or severe (P=0.0006) AEs, but not patient demographics, was predictive of treatment discontinuations. The probability of discontinuation due to moderate AEs was 0.4 and 0.5 for severe AEs.

Discussion:

The tolerability of G-GR was not affected by patient age, but was affected by AE severity. Although being female was predictive of reporting AEs, it did not influence treatment discontinuation. Given that PHN is a disease for which the risk and duration of PHN increases with age and with being female, G-GR appears to be a well-suited treatment option for PHN.

Modulation of serum BDNF levels in postherpetic neuralgia following pulsed radiofrequency of intercostal nerve and pregabalin

Aim: To study the modulation of serum BDNF levels following integrated multimodal intervention in postherpetic neuralgia (PHN). Materials & methods: A randomized, double-blind controlled study was undertaken among patients of thoracic PHN where 30 patients received pregabalin with pulsed radiofrequency and 30 controls received pregabalin with sham treatment. Results: Pain intensity (visual analog scale) was reduced earlier in intervention group (15.3 ± 5.7 at the fourth week) compared with control group (16.3 ± 6.6 at the eighth week). Serum BDNF level increased with time in both the groups with overall increase more pronounced in intervention group. Conclusion: Integrated multimodal therapy using minimally invasive pulsed radiofrequency and pregabalin in PHN was effective in early pain reduction with elevated serum BDNF levels.

The topical 5% lidocaine medicated plaster in localized neuropathic pain: a reappraisal of the clinical evidence

Topical 5% lidocaine medicated plasters represent a well-established first-line option for the treatment of peripheral localized neuropathic pain (LNP). This review provides an updated overview of the clinical evidence (randomized, controlled, and open-label clinical studies, real-life daily clinical practice, and case series). The 5% lidocaine medicated plaster effectively provides pain relief in postherpetic neuralgia, and data from a large open-label controlled study indicate that the 5% lidocaine medicated plaster is as effective as systemic pregabalin in postherpetic neuralgia and painful diabetic polyneuropathy but with an improved tolerability profile. Additionally, improved analgesia and fewer side effects were experienced by patients treated synchronously with the 5% lidocaine medicated plaster, further demonstrating the value of multimodal analgesia in LNP. The 5% lidocaine medicated plaster provides continued benefit after long-term (≤7 years) use and is also effective in various other LNP conditions. Minor application-site reactions are the most common adverse events associated with the 5% lidocaine medicated plaster; there is minimal risk of systemic adverse events and drug–drug interactions. Although further well-controlled studies are warranted, the 5% lidocaine medicated plaster is efficacious and safe in LNP and may have particular clinical benefit in elderly and/or medically compromised patients because of the low incidence of adverse events.

Profile of the capsaicin 8% patch for the management of neuropathic pain associated with postherpetic neuralgia: safety, efficacy, and patient acceptability

Capsaicin is a naturally occurring irritant active ingredient found in hot peppers. It is a ligand for transient receptor potential channel vanilloid receptors, which are found in nociceptive nerve terminals in the skin. Initial exposure to topical capsaicin leads to excitation of these receptors, release of vasoactive mediators, erythema, intense burning, pain, and thereafter desensitization of sensory neurons resulting in inhibition of pain transmission. Capsaicin 8% has been licensed for the treatment of postherpetic neuralgia pain in recent years. A single application of high-concentration capsaicin for 60 minutes for postherpetic neuralgia has been robustly evaluated. Capsaicin 8% patches are applied to the most painful areas of healthy skin and allowed to remain for 60 minutes. Treatment can be repeated every 90 days if the pain persists or returns. The patches are usually applied in specialist pain clinics where patients can be pretreated and monitored. Health care staff need to take certain precautions before administering these patches to avoid unintentional contact. Common adverse effects of the capsaicin 8% patch are transient mild-to-moderate self-limiting application-site burning, pain, erythema, pruritus, papules, swelling, dryness, and hypertension. To manage local pain from capsaicin application, the skin is pretreated with a local anesthetic such as topical lidocaine or an oral analgesic such as oxycodone for up to 5 days. A transient increase in pain is usually seen within 48 hours of patch application before the pain-relieving effect starts. Systemic absorption is minimal and clinically insignificant. The nature of administration and relatively high cost of capsaicin patches can significantly limit their use to a small number of patients with severe refractory symptoms. This review highlights recent evidence related to the use and effectiveness of the 8% capsaicin patch for Postherpetic Neuralgia and discusses its safety and side-effect profiles.

The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee

INTRODUCTION

The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications.

METHODS

The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar.

RESULTS

Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated.

CONCLUSIONS

Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

Novel High-Frequency Peripheral Nerve Stimulator Treatment of Refractory Postherpetic Neuralgia: A Brief Technical Note

OBJECTIVES

The study aims to describe an ultrasound (US)-guided peripheral nerve stimulation implant technique and describe the effect of high-frequency peripheral nerve stimulation on refractory postherpetic neuralgia.

MATERIALS AND METHODS

Following a cadaver pilot trial using US and confirmatory fluoroscopic guidance, a 52-year-old man with refractory left supraorbital neuralgia underwent combined US and fluoroscopic-guided supraorbital peripheral nerve stimulator trial. The patient was subsequently implanted with a percutaneous lead over the left supraorbital and supratrochlear nerve utilizing a high-frequency stimulation paradigm.

RESULTS

At 9 months follow-up, the pain intensity had declined from a weekly average of 8/10 to 1/10 on the pain visual analog scale (VAS). After implant, both nerve conduction and blink reflex studies were performed, which demonstrated herpetic nerve damage and frequency-specific peripheral nerve stimulation effects. The patient preferred analgesia in the supraorbital nerve distribution accomplished with high-frequency paresthesia-free stimulation (HFS) at an amplitude of 6.2 mA, a frequency of 100-1200 Hz, and a pulse width of 130 μsec, to paresthesia-mediated pain relief associated with low-frequency stimulation.

CONCLUSION

We report the implant of a supraorbital peripheral nerve stimulating electrode that utilizes a high-frequency program resulting in sustained suppression of intractable postherpetic neuralgia.