Efficacy of TENS versus Conservative Pain Control Measures in Post Herpetic Neuralgia: A Retrospective Observational Study.

ABSTRACT

Abstracts Background & Objective: To evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in treatment of post herpetic neuralgia (PHN) compared with conservative pain control measures. Methodology: A retrospective institution based observational study was conducted evaluating the records of patients visiting the dermatology OPD during last 6 consecutive months for herpes zoster and PHN. 152 out of 6240 new cases had herpes zoster and 50 of these patients had PHN which was defined as persistence of pain at the involved site one month after subsidence of rash. Pain was quantitatively noted in these patients on a visual analogue scale (VAS) from 0-10.Three treatment groups were compared only TENS therapy, TENS with analgesics (most commonly NSAIDS) and tab gabapentin along with tab amitriptyline as tricyclic antidepressant. ANOVA test was applied to study the statistical difference in treatment response between the three groups. Results: Mean baseline VAS in the groups was 6.6, 7.06 and 6.78 respectively. At the end of treatment the mean VAS was 2.1, 2.39 and 2.86 respectively. We found that there was 68.1%, 66.1% and 57.8% improvement in VAS in the individual groups respectively. The improvement was found to be statistically significant (p<0.05) in all the three treatment groups. Intergroup analysis, however, did not reveal any statistically significant difference between the groups. Conclusion: TENS is a safe and effective measure for pain control in post herpetic neuralgia patients. However, its efficacy over conventional pain control measures like NSAIDs and tab gabapentin and tricyclic antidepressants could not ascertained. Our study also revealed that initiation of antiviral therapy within 72 hours did not affect the severity of PHN.