Early Treatment with Temporary Spinal Cord Stimulation Effectively Prevents Development of Postherpetic Neuralgia

Background: Some 7.7% of the Chinese population suffer from herpes zoster each year, with 29.8% proceeding on to develop postherpetic neuralgia (PHN). This amounts to over 32 million people per year. PHN is preceded by 2 phases of pain: acute herpetic neuralgia (AHN), and subacute herpetic neuralgia (SHN). Considering the large individual and economic burden, preventing the transition of AHN/SHN to PHN is crucial. However, to date this has been difficult. Objectives: To evaluate the efficacy of temporary spinal cord stimulation (tSCS) treatment and prevention of PHN. Study Design: A retrospective, observational study. Setting: Department of Pain Medicine. Methods: From 2013 to 2017, 99 patients with AHN (n = 42), SHN (n = 34), and PHN (n = 23) underwent tSCS treatment (7-14 days) after failed pharmacologic and interventional therapies. Visual analog scale (VAS), Pittsburgh Sleep Quality Index (PSQI), and analgesic consumption were recorded at baseline, post-tSCS, and 1, 3, 6, and 12 months after tSCS treatment. Results: Pooled results demonstrated statistically significant decreases in VAS scores and PSQI post-tSCS and at 1, 3, 6, and 12 months follow-up (P < 0.001). When compared with the PHN group, both AHN and SHN groups were clinically and statistically improved in VAS scores and PSQI (P < 0.001). Analgesic consumption decreased in all 3 groups after tSCS treatment, and downward linear gradient of medication in the AHN group was more significant than that in the SHN and PHN groups. At 12 months follow-up, 2.5% (1/40) patients in the AHN group, 16.0% (4/25) in the SHN group, and 62.5% (10/16) in the PHN group had ongoing pain ≥ 3/10 VAS score requiring analgesia. Expressed differently, at 12 months, 97.5% of the AHN group and 84% of the SHN group had pain of 2/10 VAS score or less versus only 37.5% of the PHN group. Limitations: This was a single-center, retrospective study, which made it difficult to collect complete data for all variables. The therapeutic effect of tSCS could not be studied independently. Conclusions: This retrospective analyses of 99 patients treated with tSCS (7-14 days) suggests that tSCS may be effective for treating and preventing PHN. Early treatment within 4 to 8 weeks was more likely to result in pain ≤ 2/10 VAS score, improvement in sleep, and no requirement for analgesia at 12 months. Early tSCS may be a promising prevention strategy against the development of chronic neuropathic pain following herpes zoster infection. Further research is justified. Key words: Herpes zoster, zoster-related pain, postherpetic neuralgia, temporary spinal cord stimulation