A Case Report of Successful High-Frequency 10-kHz Spinal Cord Stimulator Trial in a Patient with Refractory Thoracic Postherpetic Neuralgia

Background: Spinal cord stimulation can be an effective treatment modality in patients suffering from postherpetic neuralgia who have failed first-line pharmacotherapy and continue to struggle from debilitating pain. Appropriate patient selection and having a wide array of stimulation waveforms can enhance the success of spinal cord stimulator trials. Case Report: In this article, we present a case report of a patient suffering from refractory thoracic postherpetic neuralgia who underwent a successful high-frequency 10-kHz spinal cord stimulator trial. Lead tips were successfully placed at the midline and left paramedial side of the top of T1 vertebral bodies at the source of the pain. The patient was followed up in our clinic 7 days post procedure. At the time of follow-up, our patient reported an 85% to 90% reduction in his pain symptom scores and a significant improvement in his quality of life. Conclusion: Similar successful trials for postherpetic neuralgia have been reported in small studies using traditional low-frequency stimulation waveforms. However, to our knowledge, this is the first report of a successful spinal cord stimulator trial using high-density 10 kHz. Key words: Postherpetic neuralgia, high-frequency spinal cord stimulator, acute herpes zoster

Efficacy of Pain Relief in Different Postherpetic Neuralgia Therapies: A Network Meta-Analysis

Background: Postherpetic neuralgia (PHN) is a nerve pain disease usually controlled by different therapies, i.e., topical therapies, antiepileptics, analgesics, antipsychotics, antidepressants, anti-dementia drugs, antivirals, amitriptyline, fluphenazine, and magnesium sulfate. It is believed that different therapies may lead to different levels of pain relief. Objectives: We proposed this study to compare the efficacy of PHN treatments. Study Design: We conducted a systematic review of the current literature. All relevant studies were retrieved from online databases. The standardized mean difference (SMD) was used for pain relief measurement in different PHN therapies. Setting: A conventional meta-analysis and a network meta-analysis (NMA) were carried out together with the surface under the cumulative ranking curve (SUCRA) for each therapy calculated regarding their efficacy. Results: A pairwise meta-analysis suggested that 4 treatment classes, including topical therapies, antiepileptics, analgesics, and antidepressants, exhibited better pain relief results than placebo. Likewise, a NMA suggested that patients with 4 treatment classes exhibited significant improvements in pain scores compared to those with placebo. Limitations: There is a lack of direct head-to-head comparisons of some treatments, especially for antivirals, anti-dementia drugs, and magnesium sulfate. Secondly, the specific agents belonging to the same class of therapies might exhibit different effects (gabapentin and carisbamate) with different mechanisms (opioids and ketamine) on reducing pain, and some agents were hard to find in literatures and were not involved in our study, which may influence our results. Conclusions: Analgesics were preferable to other treatments with respect to pain relief for PHN, while antivirals appeared to be less effective than other therapies. Key words: Postherpetic neuralgia, topical agents, antiepileptics, analgesics, antipsychotics, antidepressants