Background: Postherpetic neuralgia (PHN) occurs in 9% to 34% of herpes zoster (HZ) patients, and the incidence of PHN is positively correlated with age. A number of patients suffer from poor therapeutic effects or intolerable side effects and need to accept minimally invasive analgesia.
Objectives: This study aimed to investigate the effects of spinal cord stimulation (SCS) and pulsed radiofrequency (PRF) on the treatment of elderly patients with HZ-related pain persisting beyond the acute phase.
Study design: A prospective, randomized-controlled trial.
Setting: Research was conducted at the National Pain Management and Research Center, China-Japan Friendship Hospital (Beijing, China).
Methods: We selected 63 patients aged over 50 years with zoster-related pain of 1 to 6 months onset. They were randomly divided into an SCS group and a PRF group. In the SCS group, the stimulus electrodes were placed in the affected spinal ganglion segment of the epidural space for 2 weeks. In the PRF group, the radiofrequency needle was percutaneously punctured in the affected dorsal root ganglion. The main outcome measures were the Numeric Rating Scale (NRS-11) score, response rate, and complete remission rate. The secondary endpoint was defined as the use of analgesics and calcium channel antagonists.
Results: The NRS-11 score in the SCS group decreased to 2.90 ± 1.83 (1 week post operation) and 4.37 ± 2.43 (24 weeks post operation), while that in the PRF group decreased to 3.13 ± 1.78 and 4.23 ± 2.64, respectively (compared with baseline, P < .001); there was no significant difference between the 2 groups (P > .05) . The effective rate of pain management was in the range of 56.67% to 81.25%, and the complete pain relief rate ranged from 37% to 71%. The number of patients still using analgesics and calcium channel antagonists after operation were significantly less than those pre-operation (P < .001). Univariate and multivariate logistic regression analyses showed that the operation method, age, gender, and course of disease did not affect surgical efficacy.
Limitations: The main limitation of this study is that all the cases were from the same center.
Conclusion: It therefore can be concluded that SCS and PRF can effectively relieve PHN.
Key words: Spinal cord stimulation, pulsed radiofrequency, postherpetic neuralgia.