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

The efficacy of ultrasound-guided pulsed radiofrequency in the treatment of primary glossopharyngeal neuralgia

Objective

This study evaluates the clinical efficacy and safety of ultrasound-guided long duration, high voltage pulse radiofrequency (PRF) in managing primary glossopharyngeal neuralgia (GPN).

Methods

Clinical data were retrospectively analyzed for 13 patients with primary GPN who underwent this treatment between August 2019 and October 2022. Visual Analog Scale (VAS) scores were assessed pre-treatment and at 1 week, 1 month, 3 months, and 6 months post-treatment. Additionally, the rates of discontinuation of oral oxcarbazepine and pregabalin, efficacy, and complication rates at 6 months post-procedure were monitored.

Results

Significant post-treatment pain relief, was observed across all patients, with statistically significant improvements in VAS scores (p < 0.05). Discontinuation rates for oxcarbazepine and pregabalin were also high (p < 0.05). At the 6-month follow-up, 69.23% of patients achieved excellent and good efficacy, 84.61% demonstrated overall effectiveness, while 15.38% showed poor efficacy. No critical complications were reported in any case.

Conclusion

Ultrasound-guided, long-term, high-voltage PRF effectively relieves primary glossopharyngeal neuralgia and improves quality of life. Featuring ease of operation, high safety and minimal complications making it a promising approach for clinical application.

Anatomo-physiological basis and applied techniques of electrical neuromodulation in chronic pain

Chronic pain, a complex and debilitating condition, poses a significant challenge to both patients and healthcare providers worldwide. Conventional pharmacological interventions often prove inadequate in delivering satisfactory relief while carrying the risks of addiction and adverse reactions. In recent years, electric neuromodulation emerged as a promising alternative in chronic pain management. This method entails the precise administration of electrical stimulation to specific nerves or regions within the central nervous system to regulate pain signals. Through mechanisms that include the alteration of neural activity and the release of endogenous pain-relieving substances, electric neuromodulation can effectively alleviate pain and improve patients' quality of life. Several modalities of electric neuromodulation, with a different grade of invasiveness, provide tailored strategies to tackle various forms and origins of chronic pain. Through an exploration of the anatomical and physiological pathways of chronic pain, encompassing neurotransmitter involvement, this narrative review offers insights into electrical therapies' mechanisms of action, clinical utility, and future perspectives in chronic pain management.

Brain-Derived Neurotrophic Factor, Nociception, and Pain

This article examines the involvement of the brain-derived neurotrophic factor (BDNF) in the control of nociception and pain. BDNF, a neurotrophin known for its essential role in neuronal survival and plasticity, has garnered significant attention for its potential implications as a modulator of synaptic transmission. This comprehensive review aims to provide insights into the multifaceted interactions between BDNF and pain pathways, encompassing both physiological and pathological pain conditions. I delve into the molecular mechanisms underlying BDNF's involvement in pain processing and discuss potential therapeutic applications of BDNF and its mimetics in managing pain. Furthermore, I highlight recent advancements and challenges in translating BDNF-related research into clinical practice.

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.

Short-Term Spinal Cord Stimulation or Pulsed Radiofrequency for Elderly Patients with Postherpetic Neuralgia: A Prospective Randomized Controlled Trial

Background. Postherpetic neuralgia (PHN) is the most common and severe complication after varicella-zoster infection, especially in elderly patients. PHN is always refractory to treatment. Both pulsed radiofrequency (PRF) and short-term spinal cord stimulation (stSCS) have been used as effective analgesia methods in clinic. However, which technique could provide better pain relief remains unknown. Objectives. This study is aimed at evaluating the efficacy and safety of PRF and stSCS in elderly patients with PHN. Study Design. A prospective, randomized-controlled study. Setting. Department of Pain Management, the Second Affiliated Hospital of Guangzhou Medical University. Methods. A total of 70 elderly patients with PHN were equally randomized to the PRF group or stSCS group. Patients in the PRF group received PRF treatment, while patients in the stSCS group received stSCS treatment. The primary outcome was the effective rate. The secondary outcomes included the Visual Analogue Scale (VAS), the 36-Item Short Form Health Survey Questionnaire (SF-36), and the pregabalin dosage. All outcomes were evaluated at baseline and at different postoperative time points. Results. At 12 months after surgery, the effective rate reached 79.3% in stSCS group, while 42.1% in PRF group. The effective rate was significantly higher in the stSCS group than in the PRF group at 3, 6, and 12 months after surgery. VAS scores decreased significantly at each postoperative time point in both groups ( $P<0.001$ ). The VAS scores were significantly lower in the stSCS group than in the PRF group at 3, 6, and 12 months after surgery. SF-36 scores (bodily pain and the physical role) were significantly improved at each postoperative time point in both groups ( $P<0.001$ ). The SF-36 scores were significantly higher in the stSCS group than in the PRF group at some postoperative time points. The pregabalin dosage was significantly lower in the stSCS group than in the PRF group at 3, 6, and 12 months after surgery. Limitations. A single-center study with a relatively small sample size. Conclusions. Both PRF and stSCS are effective and safe neuromodulation techniques for elderly patients with PHN. However, stSCS could provide better and longer-lasting analgesic effect compared to PRF.

Comparing the efficacy and safety of short-term spinal cord stimulation and pulsed radiofrequency for zoster-related pain: A systematic review and meta-analysis

BACKGROUND

Pulsed radiofrequency (PRF) is a commonly used method for the treatment of zoster-related pain in the clinic. However, PRF therapy has a high recurrence rate and many adverse reactions. Recent studies have shown that short-term spinal cord stimulation (stSCS) can effectively alleviate zoster-related pain. Due to the lack of evidence, it is unclear whether stSCS is superior to PRF in the efficacy of treating zoster-related pain.

OBJECTIVE

This study aimed to compare the efficacy and safety of stSCS and PRF for zoster-related pain.

METHODS

We searched seven electronic databases from the establishment of the database to January 2021. Related randomized controlled trials were included in this meta-analysis. After extracting the data and evaluating the methodological quality of the included trials, the outcome indicators were statistically analyzed by using RevManV.5.3.

RESULTS

This meta-analysis included 6 trials with a total of 509 patients. Compared with PRF group, stSCS group showed lower pain intensity (standardized mean difference=-0.83, 95%CI [-1.37, -0.30], P=.002), better sleep quality (mean difference=-1.43, 95%CI [-2.29, -0.57], P=.001), lower pain rating index scores, and less incidence of adverse events (RR=0.32, 95%CI [0.12, 0.83], P<.05). However, the efficacies of PRF and stSCS for treating postherpetic neuralgia were consistent in the response rate (RR= 1.10, 95% CI [0.82, 1.48], P=.51) and the complete remission rate (RR=1.05, 95% CI [0.66, 1.68], P=.84).

CONCLUSIONS

In this study, stSCS showed a better analgesic effect and higher safety than PRF. Our meta-analysis results suggested that stSCS may be a feasible and safe invasive treatment for zoster-related pain. However, high-quality, randomized controlled trials with large sample sizes are needed to further verify our conclusions.

Modulation of signal transduction gene expression following pulsed radiofrequency in dorsal root ganglia and pregabalin therapy

Introduction: A randomized controlled study was conducted to assess modulation of signal transduction genes (PKA, PKC and ERK) following integrated multimodal approach encompassing pulsed radiofrequency treatment (PRF) of dorsal root ganglion and pregabalin in thoracic postherpetic neuralgia (PHN). Clinical variables such as pain intensity and quality of life were also explored. Material & methods: A total of 40 Patients of PHN were recruited. 20 patients randomly assigned to each of the two groups, group PP administered PRF with pregabalin and group SP administered pregabalin alone. Results: Significant downregulation of PKA and ERK observed in group PP at end of 10th week (p < 0.05). A significantly positive correlation demonstrated between Visual analog scale scores and signal transduction genes expression in PHN patients. Conclusion: Downregulation of all three signal transduction genes was observed following the integrated multimodal approach; however, significant downregulation was observed with PKA and ERK only. A positive correlation observed between signal transduction gene expression and visual analog scale scores signify their role in the pathogenesis of PHN.

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.

Efficacy of Pulsed Radiofrequency in Herpetic Neuralgia: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVES

Herpes zoster and postherpetic neuralgia (PHN) are often refractory to current standard treatments and can reduce patients' quality of life (QoL). Pulsed radiofrequency (PRF) effectively controls intractable neurological pain. The aim of the study was to conduct a systematic review and meta-analysis to evaluate the efficacy of PRF in PHN management.

MATERIALS AND METHODS

We searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs) published up to October 2019. The primary outcomes were pain levels and rescue analgesia at different postintervention time intervals. The secondary outcomes were QoL and sleep quality.

RESULTS

We reviewed 6 RCTs involving 420 patients. The meta-analysis revealed that the PRF group exhibited significantly lower pain scores in PHN than did the control group at 2 to 3 days (weighted mean differences [WMD]=-2.82; 95% confidence interval [CI]: -5.08 to -0.55), 1 week (WMD=-2.95; 95% CI: -4.53 to -1.37), 2 weeks (WMD=-3.17; 95% CI: -4.11 to -2.23), 4 weeks (WMD=-2.59; 95% CI: -3.40 to -1.79), 8 weeks (WMD=-3.02; 95% CI: -4.17 to -1.88), and 6 months (WMD=-1.94; 95% CI: -2.85 to -1.03). After intervention, QoL was significantly higher in the PRF group than in the control group. No major complications were reported.

DISCUSSION

PRF safely and effectively reduced pain scores and improved QoL in patients with herpes zoster in the cervical to lumbosacral areas. PRF could be considered during refractory PHN treatment. Future studies require standardized PRF settings and outcome assessment tools, including physical and emotional function assessments.

Efficacy of different interventions for the treatment of postherpetic neuralgia: a Bayesian network meta-analysis

Objective

We aimed to perform a network meta-analysis that combined both direct and indirect evidence to compare the relative efficacy of interventional therapies to treat patients with postherpetic neuralgia (PHN) and to determine the treatments’ superiority and validity.

Method

A conventional paired meta-analysis was performed. This was followed by a network meta-analysis using the Bayesian framework.

Results

Botulinum toxin type A and pulsed radiofrequency (PRF) were the two most effective individual interventions. For combination therapy, PRF + nerve block (NB) was the best choice, followed by subcutaneous injection or local infiltration (SC) + NB + ozone (O3). However, the combination of PRF + NB + SC showed reduced the efficacy compared with each treatment and was highly invasive for patients. After a long-term follow-up, PRF was shown to be the most effective therapy for treating patients with PHN.

Conclusions

Regular anti-neuropathic drug administration that was accompanied by interventional therapies at an early stage is the best choice to treat patients with PHN. Appropriate combinations of different interventions show improved pain relief. Clinicians should manage therapeutic regimens on the basis of the patients specific condition and existing measures and strive to achieve personalized treatment.

Combined Treatment of Adipose Derived-Mesenchymal Stem Cells and Pregabalin Is Superior to Monotherapy for the Treatment of Neuropathic Pain in Rats

Aims

Neuropathic pain following nerve injury does not respond well to most available pharmacological remedies. We aimed to compare the outcome of the addition of adipose-derived mesenchymal stem cells (ADMSCs) to pregabalin for neuropathic pain treatment.

Methods

Adult female albino rats (n = 100) were randomized to receive traumatic sciatic nerve injury or sham. Animals were then randomized to ADMSC treatment with or without pregabalin. We conducted a battery of neurobehavioral and electrophysiological to assess neuropathic pain. Following sacrifice, we evaluated the histological changes and gene expression of brain-derived neurotrophic factor (BDNF) in the sciatic nerve. Serum and sciatic nerve tissue pro- and inflammatory cytokine levels were also assessed.

Results

(1) All treatments significantly improved thermal withdrawal latency, sciatic nerve conduction velocity, and proinflammatory cytokine levels in injured animals, with no significant effect of the combined treatments compared to pregabalin monotherapy (p < 0.05 each). (2) Combined treatment significantly improved medial gastrocnemius electromyographic amplitude and sciatic function index compared to pregabalin monotherapy (p < 0.05 each). (3) Combined treatment significantly increased the BDNF expression, decreased anti-inflammatory cytokine (p < 0.05 each), and restored the structural nerve damage, compared to pregabalin monotherapy.

Conclusions

Combined treatment is associated with greater improvement of the sciatic nerve structure and function. Further studies are warranted to study the mechanism of action of the combined treatment to improve neuropathic pain.

Post-herpetic Neuralgia: A Systematic Review of Current Interventional Pain Management Strategies

Background:

Post-herpetic neuralgia (PHN) is usually a constant or intermittent burning, stabbing, or sharp shooting pain with hyperalgesia or allodynia, persisting beyond the healing of herpetic skin lesions. This review was carried out in concordance to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We used PICOS (Population, Intervention, Control, and Outcome Study) design for inclusion of potential studies into this review. Online literature available in PubMed, Cochrane, and Embase was searched for studies from January 1995 till March 2020, which evaluated interventional treatments in PHN by an independent reviewer, using the relevant medical subject heading (MeSH) terms. We analyzed the following outcome parameters with regard to each intervention—pain status at predefined fixed intervals after the intervention, quality of sleep using any of the reported questionnaires, analgesic consumption, functional evaluation, and quality of life assessment after the intervention.

Conclusion:

Interventional pain management options provide effective and long-lasting pain relief to patients not responding to medical management. The choice of intervention will depend on the region involved, cost, and invasiveness. Simple procedures such as intercostal nerve blocks/neurolysis, stellate ganglion blocks, paravertebral neurolysis, epidural steroid injections, and dorsal root ganglion–radiofrequency ablation are effective interventions, and if they fail, spinal cord stimulators could be effective in the hands of experienced pain physicians.

Neuropeptide system parameters in acute herpes zoster

The neuropeptides comprise an important part in the nervous system interacting with endocrine and immune systems. Peptide regulators are responsible for the continuity of communicating elements, which support homeostasis, however, despite abundant research examining neuropeptides, not all specific mechanisms and features of interacting proteins with cells and immune components have been uncovered. Objective: to perform a comprehensive assessment of neuropeptide system in patients with herpes zoster. Materials and methods: 106 in-hospital patients were examined diagnosed with herpes zoster within 2016–2019 period. Control group consisted of 30 healthy age- and sex-matched volunteers. Blood serum was collected after verifying diagnosis on day 1. After discharge, patients were monitored for signs of pain syndrome and overall state within 3 months. It allowed to divide patients into 3 groups retrospectively. Group 1 — patients with herpes zoster, accompanied by mild or moderate pain syndrome; group 2 — patients with herpes zoster, accompanied by severe pain; group 3 — patients with herpes zoster, complicated by postherpetic neuralgia. Level of serum protein s100B, myelin basic protein, nerve growth factor, brain-derived neurotrophic factor, neuron specific enolase was measured by using specific reagents purchased from “RD Diagnostics Inc.” (США). Results. it was found that level of serum protein S100B in all groups was significantly increased compared to control group, showing no inter-group differences. Amount of myelin basic protein in all study groups vs. control was significantly higher. Moreover, level of these parameters in group 2 vs. group 1 and 3 was significantly elevated. In addition, level of nerve growth factor was significantly increased in group 1 vs. groups 2 and 3, whereas in group 3 it was significantly lower than in control and group 2. Brain-derived neurotrophic factor was significantly decreased in all the study groups compared to control, showing no significant intergroup differences. Level of neuron-specific enolase was significantly increased in group 3 vs. control as well as group 1 and 2. The data obtained allowed to identify two parameters for assessing a risk of postherpetic neuralgia in acute herpes zoster, as well as provided deeper insights into the pathogenesis of neuroimmune disorders accompanying herpes zoster.

Correlation Between Thalamus-Related Functional Connectivity and Serum BDNF Levels During the Periovulatory Phase of Primary Dysmenorrhea

The thalamus is a key region for the transmission of nociceptive information in the central modulation of pain and has been studied in the setting of numerous chronic pain conditions. Brain-derived neurotrophic factor (BDNF) is considered an important modulator for mediating nociceptive pathways in chronic pain. The present study aimed to investigate whether there was thalamus-related abnormal functional connectivity or relevant serum BDNF level alterations during periovulation in long-term primary dysmenorrhea (PDM). Thalamic subregions were defined according to the Human Brainnetome Atlas. Functional connectivity analyses were performed in 36 patients in the periovulatory phase and 29 age-, education-, and gender-matched healthy controls. Serum BDNF levels were evaluated by enzyme-linked immunosorbent assay and a significantly higher BDNF level was detected in PDM patients. Compared with HCs, PDM patients had abnormal functional connectivity of thalamic-subregions, mainly involving with prefrontal cortex, sensorimotor cortex, and temporal cortex. In addition, the functional connectivity of thalamic-subregions showed significant interactive effect correlated with serum BDNF level between PDM and HCs. It has been suggested that there were maladaptive or adoptive alteration associated with chronic menstrual pain even without the ongoing menstrual pain. BDNF might play a role in the development and chronicity of central nervous system dysfunction. These findings provided more accurate information about the involvement of the thalamus in the pathophysiology of PDM.

The Effect of Interventional Pain Management on Treating Postherpetic Neuralgia

Background:

Herpes zoster (HZ) is identified to induce postherpetic neuralgia (PHN) which is difficult to cure. PHN-related pain brings patients not only physical discomfort but also mental depression and anxiety. Currently, the main purpose of PHN treatment is to reduce patients’ pain. Now treatment combining some international pain management and drug therapy has come up.

Aims and Objective:

This study aims to evaluate the effect of interventional management through meta-analysis.

Materials and Methods:

Interventional pain management was defined as a direct strategy on nerve through physical or chemical method. Drug therapy was always regarded as control. Potentially relevant articles were searched in PubMed, EMBASE, and the Cochrane Library through key words by consensus. Pain severity was evaluated by a validated visual analog scale (VAS). Moreover, the weighted mean difference was used to calculate pain intensity. Some trails recorded the efficiency rate and odds ratio was used to calculate the effectiveness. Statistical heterogeneity was measured by the value of I², and when statistical I² > 50%, subgroup analysis was used to seek for the source of heterogeneity.

Results:

Pulsed radiofrequency (PRF) combined with medication reduced the VAS scores at 1, 2, 4, and 8 weeks after treatment. The nerve block combined with medication reduced VAS scores at 8 weeks after treatment, but there is no difference between the results of medication alone at 1, 2, and 4 weeks after treatment.

Conclusion:

The interventional mean of PRF combined with medication has a good effect on PHN. The effect of nerve block combined with medication on PHN seems to be the same as that of medication alone. Besides, a long period with high-quality randomized controlled trial should be done to verify the results.

Radiofrequency techniques to treat chronic knee pain: a comprehensive review of anatomy, effectiveness, treatment parameters, and patient selection

Background

The use of radiofrequency ablation (RFA) procedures to treat chronic knee pain has surged in the past decade, though many questions remain regarding anatomical targets, selection criteria, and evidence for effectiveness.

Methods

A comprehensive literature review was performed on anatomy, selection criteria, technical parameters, results of clinical studies, and complications. Databases searched included MEDLINE and Google Scholar, with all types of clinical and preclinical studies considered.

Results

We identified nine relevant clinical trials, which included 592 patients, evaluating knee RFA for osteoarthritis and persistent postsurgical pain. These included one randomized, placebo-controlled trial, one randomized controlled trial evaluating RFA as add-on therapy, four comparative-effectiveness studies, two randomized trials comparing different techniques and treatment paradigms, and one non-randomized, controlled trial. The results of these studies demonstrate significant benefit for both reduction and functional improvement lasting between 3 and 12 months, with questionable utility for prognostic blocks. There was considerable variation in the described neuroanatomy, neural targets, radiofrequency technique, and selection criteria.

Conclusion

RFA of the knee appears to be a viable and effective treatment option, providing significant benefit to well-selected patients lasting at least 3 months. More research is needed to better identify neural targets, refine selection criteria to include the use of prognostic blocks, optimize treatment parameters, and better elucidate relative effectiveness compared to other treatments.

Combined therapy of pulsed radiofrequency and nerve block in postherpetic neuralgia patients: a randomized clinical trial

Caused by viral infection, postherpetic neuralgia (PHN) is the most common chronic neuropathic pain. Various treatment modalities such as early use of nerve block therapy (NBT) and pulsed radiofrequency (PRF) have been studied in reducing pain, however, no consistent success was achieved in all the patients treated with single regimen. The combined therapy of PRF and NBT with different targeting mechanism are of interest and remains to be determined. Here we investigated the combined effects of pulsed radiofrequency (PRF) with nerve block therapy (NBT) in PHN patients in a prospective randomized clinical trial. Sixty PHN patients were divided into four groups (n = 15 each): the conventional puncture group (group CP), the nerve block therapy group (group NB), the PRF group (group PRF), and the combined treatment group (PRF combined with nerve block therapy (group CT). To evaluate the extent of remission of hyperalgesia, we recorded the visual analogue scale (VAS) scores during cotton swab reaction before and after treatment and in the resting and active pain states. In addition, blood samples were collected and plasma cytokine and neuropeptides such as interleukin-6 (IL-6), substance P (SP), and β-endorphin (β-EP) were measured by enzyme-linked immunosorbent assay (ELISA) at the admission (basic state), before the operation, and at 12 h postoperatively. The number of adverse events (nausea, vomiting, constipation, puncture point hemorrhage, swelling and redness) within 12 h of the treatment were also documented. Our results showed that VAS scores during cotton swab reaction decreased after treatment in all patients (p < 0.05). Compared to group CP, plasma IL-6 and SP levels decreased (p < 0.05) and β-EP levels increased (p < 0.05) in groups NB, PRF, and CT. There were no significant differences in adverse events among groups (p > 0.05). We found that PRF in combination with NBT increased β-EP levels and decreased plasma IL-6 and SP, thereby alleviating pain and hyperalgesia in PHN patients. Taken together, our data suggest combined therapy of PRF and NBT is effective and safe for PHN patients.