Prevention of post-herpetic neuralgia using transcutaneous electrical nerve stimulation

Efficacy and Safety of UVA1 Phototherapy Adjunct Treatment for Acute Cutaneous Inflammations and Neuralgia of Herpes Zoster: A Prospective, Randomized, Open-Label, Blinded End-Point Study

Background: Previous case reports hint ultraviolet A1 (UVA1) phototherapy as a novel adjunct treatment for acute cutaneous inflammations and neuralgia of herpes zoster, but its clinical effectiveness and safety in this condition are not yet proven by clinical trials. Objectives: To determine the efficacy and safety of UVA1 phototherapy as an adjunct treatment for acute inflammation and neuralgia in herpes zoster. Methods: A total of 60 patients with moderate-to-severe acute herpes zoster were randomly divided into two parallel groups. Group I received regular treatment and UVA1, and Group II received regular treatment alone. Time of blister crusting and acute erythema subside, assessment of pain, sleep, anxiety, and quality of life were recorded accordingly. Results: In Groups I and II, 28 and 29 patients completed the treatment and follow-up, respectively, with no significant demographic or baseline differences. UVA1 therapy notably reduced blister crusting time and acute erythema subside time and achieved more rapid pain relief within the first 2 weeks. However, it did not significantly alter the rate of postherpetic neuralgia occurrence. Additionally, UVA1 therapy significantly improved anxiety and quality of life scores at the 2-week mark. The primary adverse effects were mild burning and hyperpigmentation at the treatment site. Conclusions: UVA1 phototherapy as an adjunct treatment can expedite the resolution of acute inflammatory cutaneous lesions and neuralgia associated with herpes zoster, providing swifter relief from anxiety and enhancing patient quality of life during the acute phase, with demonstrated good tolerability and safety.

Non-oral pharmacological interventions in the management of herpes zoster-related pain: a review of current research

Herpes zoster-associated pain is a difficult-to-treat pathologic pain that seriously affects patients' quality of life. In recent years, emerging therapeutic techniques such as autologous platelet-rich plasma, sympathetic nerve block and pulsed radiofrequency have been gradually applied in the field of pain with the advantages of less trauma, quicker recovery and significant efficacy. These therapeutic options have become a new hope for the treatment of herpes zoster-associated pain. This article reviews the studies on herpes zoster-associated pain in non-oral drug therapy, summarizes the efficacy, safety, and possible mechanisms, and provides a reference basis for clinical treatment.

Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress

BACKGROUND

Chronic pain conditions impose significant burdens worldwide. Pharmacological treatments like opioids have limitations. Non-invasive non-pharmacological therapies (NINPT) encompass diverse interventions including physical, psychological, complementary and alternative approaches, and other innovative techniques that provide analgesic options for chronic pain without medications.

MAIN BODY

This review elucidates the mechanisms of major NINPT modalities and synthesizes evidence for their clinical potential across chronic pain populations. NINPT leverages peripheral, spinal, and supraspinal mechanisms to restore normal pain processing and limit central sensitization. However, heterogeneity in treatment protocols and individual responses warrants optimization through precision medicine approaches.

CONCLUSION

Future adoption of NINPT requires addressing limitations in standardization and accessibility as well as synergistic combination with emerging therapies. Overall, this review highlights the promise of NINPT as a valuable complementary option ready for integration into contemporary pain medicine paradigms to improve patient care and outcomes.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Characterising the Features of 381 Clinical Studies Evaluating Transcutaneous Electrical Nerve Stimulation (TENS) for Pain Relief: A Secondary Analysis of the Meta-TENS Study to Improve Future Research

Background and Objectives: Characterising the features of methodologies, clinical attributes and intervention protocols, of studies is valuable to advise directions for research and practice. This article reports the findings of a secondary analysis of the features from studies screened as part of a large systematic review of TENS (the meta-TENS study). Materials and Methods: A descriptive analysis was performed on information associated with methodology, sample populations and intervention protocols from 381 randomised controlled trials (24,532 participants) evaluating TENS delivered at a strong comfortable intensity at the painful site in adults with pain, irrespective of diagnosis. Results: Studies were conducted in 43 countries commonly using parallel group design (n = 334) and one comparator group (n = 231). Mean ± standard deviation (SD) study sample size (64.05 ± 58.29 participants) and TENS group size (27.67 ± 21.90 participants) were small, with only 13 of 381 studies having 100 participants or more in the TENS group. Most TENS interventions were ‘high frequency’ (>10 pps, n = 276) and using 100 Hz (109/353 reports that stated a pulse frequency value). Of 476 comparator groups, 54.2% were active treatments (i.e., analgesic medication(s), exercise, manual therapies and electrophysical agents). Of 202 placebo comparator groups, 155 used a TENS device that did not deliver currents. At least 216 of 383 study groups were able to access other treatments whilst receiving TENS. Only 136 out of 381 reports included a statement about adverse events. Conclusions: Clinical studies on TENS are dominated by small parallel group evaluations of high frequency TENS that are often contaminated by concurrent treatment(s). Study reports tended focus on physiological and clinical implications rather than the veracity of methodology and findings. Previously published criteria for designing and reporting TENS studies were neglected and this should be corrected in future research using insights gleaned from this analysis.

Pharmacological and non-pharmacological strategies for preventing postherpetic neuralgia: a systematic review and network meta-analysis

Background

Postherpetic neuralgia (PHN) is a refractory complication of herpes zoster (HZ). To prevent PHN, various strategies have been aggressively adopted. However, the efficacy of these strategies remains controversial. Therefore, we aimed to estimate the relative efficacy of various strategies used in clinical practice for preventing PHN using a network meta-analysis (NMA).

Methods

We performed a systematic and comprehensive search to identify all randomized controlled trials. The primary outcome was the incidence of PHN at 3 months after acute HZ. We performed both frequentist and Bayesian NMA and used the surface under the cumulative ranking curve (SUCRA) values to rank the interventions evaluated.

Results

In total, 39 studies were included in the systematic review and NMA. According to the SUCRA value, the incidence of PHN was lower in the order of continuous epidural block with local anesthetics and steroids (EPI-LSE), antiviral agents with subcutaneous injection of local anesthetics and steroids (AV + sLS), antiviral agents with intracutaenous injection of local anesthetics and steroids (AV + iLS) at 3 months after acute HZ. EPI-LSE, AV + sLS and AV + iLS were also effective in preventing PHN at 1 month after acute HZ. And paravertebral block combined with antiviral and antiepileptic agents was effective in preventing PHN at 1, 3, and 6 months.

Conclusions

The continuous epidural block with local anesthetics and steroid, antiviral agents with intracutaneous or subcutaneous injection of local anesthetics and a steroid, and paravertebral block combined with antiviral and antiepileptic agents are effective in preventing PHN.

Effect of pain neuroscience education and transcutaneous electrical nerve stimulation on trigeminal postherpetic neuralgia. A case report

Introduction: Postherpetic neuralgia (PHN) is a complex neuropathic painful condition in which pain is a direct consequence of the response to peripheral nerve damage experienced during herpes zoster attack. PHN is the most common chronic complication of herpes zoster and it causes considerable suffering, affecting the physical functioning and psychological well-being of patients. Objective: To describe the effect of a conservative treatment using pain neuroscience education (PNE) and transcutaneous electrical nerve stimulation (TENS) in a patient with trigeminal PHN. Case Description: A 67-year-old woman sought care for pain, dysfunction, and sensory loss in the left jaw. The assessment included: 1) pain, using the numerical pain rating scale (NPRS), pressure pain threshold (PPT), Douleur Neuropathique 4 (DN4), McGill Pain Questionnaire (MPQ), Graded Chronic Pain Scale (GCPS), and classic body charts of the cranial region; 2) somatosensory function, by means of mechanical detection threshold (MDT) and pressure pain threshold (PPT); 3) jaw function, using the Jaw Functional Limitation Scale-20 (JFLS-20); and 4) psychosocial features, by means of the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorders Questionnaire-7 (GAD-7). Treatment consisted of 12 sessions of PNE and TENS. Outcomes: After treatment, a clinically significant improvement in NPRS, DN4, MDT, GCPS, and PHQ-9 was observed. Conclusion: In this case report, a treatment based on the combination of PNE and TENS seemed to have contributed to improving pain, sensory abnormalities, and jaw function. Psychosocial factors also showed a trend to improve after the treatment.

Transcutaneous electrical nerve stimulation (TENS): a review of applications in dermatology

Background: A transcutaneous electrical nerve stimulation (TENS) unit is an inexpensive, accessible therapeutic device with multiple dermatology-related uses.Objective: This review aims to describe the dermatological applications of TENS.Methods: PubMed was searched for literature related to TENS in dermatology. Articles describing this association were reviewed for evidence.Results: TENS offered pain relief during photodynamic therapy for the treatment of actinic keratoses, with a reduction in visual analog scale (VAS) scores for patients using TENS during photodynamic therapy compared to those using no intervention. In the treatment of refractory postherpetic neuralgia pain, patients received greater pain relief when given pregabalin along with TENS therapy compared to pregabalin and no TENS therapy. TENS was the most effective therapy in reducing the incidence of PHN when compared to antiviral agents or combination therapy. The administration of TENS three times per week for four weeks improved VAS scores for pruritus associated with atopic dermatitis and lichen simplex chronicus. This benefit extended into the treatment of other conditions, resulting in improvement of pruritus measured by VAS and Dermatology Life Quality Index scores for macular amyloidosis and lichen planus.Conclusions: TENS is beneficial in the field of dermatology, particularly involving the relief of chronic pruritus.

Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults

BACKGROUND

Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn.

OBJECTIVES

To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies.

SELECTION CRITERIA

We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE.

MAIN RESULTS

We included 15 studies with 724 participants. We found a range of treatment protocols in terms of duration of care, TENS application times and intensity of application. Briefly, duration of care ranged from four days through to three months. Similarly, we found variation of TENS application times; from 15 minutes up to hourly sessions applied four times daily. We typically found intensity of TENS set to comfortable perceptible tingling with very few studies titrating the dose to maintain this perception. Of the comparisons, we had planned to explore, we were only able to undertake a quantitative synthesis for TENS versus sham TENS. Insufficient data and large diversity in the control conditions prevented us from undertaking a quantitative synthesis for the remaining comparisons.For TENS compared to sham TENS, five studies were suitable for pooled analysis. We described the remainder of the studies in narrative form. Overall, we judged 11 studies at high risk of bias, and four at unclear risk. Due to the small number of eligible studies, the high levels of risk of bias across the studies and small sample sizes, we rated the quality of the evidence as very low for the pooled analysis and very low individual GRADE rating of outcomes from single studies. For the individual studies discussed in narrative form, the methodological limitations, quality of reporting and heterogeneous nature of interventions compared did not allow for reliable overall estimates of the effect of TENS.Five studies (across various neuropathic conditions) were suitable for pooled analysis of TENS versus sham TENS investigating change in pain intensity using a visual analogue scale. We found a mean postintervention difference in effect size favouring TENS of -1.58 (95% confidence interval (CI) -2.08 to -1.09, P < 0.00001, n = 207, six comparisons from five studies) (very low quality evidence). There was no significant heterogeneity in this analysis. While this exceeded our prespecified minimally important difference for pain outcomes, we assessed the quality of evidence as very low meaning we have very little confidence in this effect estimate and the true effect is likely to be substantially different from that reported in this review. Only one study of these five investigated health related quality of life as an outcome meaning we were unable to report on this outcome in this comparison. Similarly, we were unable to report on global impression of change or changes in analgesic use in this pooled analysis.Ten small studies compared TENS to some form of usual care. However, there was great diversity in what constituted usual care, precluding pooling of data. Most of these studies found either no difference in pain outcomes between TENS versus other active treatments or favoured the comparator intervention (very low quality evidence). We were unable to report on other primary and secondary outcomes in these single trials (health-related quality of life, global impression of change and changes in analgesic use).Of the 15 included studies, three reported adverse events which were minor and limited to 'skin irritation' at or around the site of electrode placement (very low quality evidence). Three studies reported no adverse events while the remainder did not report any detail with regard adverse events.

AUTHORS' CONCLUSIONS

In this review, we reported on the comparison between TENS and sham TENS. The quality of the evidence was very low meaning we were unable to confidently state whether TENS is effective for pain control in people with neuropathic pain. The very low quality of evidence means we have very limited confidence in the effect estimate reported; the true effect is likely to be substantially different. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment modality.