Effectiveness of combined pulsed radiofrequency and steroid injection to the dorsal root ganglion in the treatment of postherpetic neuralgia: a prospective randomized clinical trial

Abstract

Purpose The present study aimed to evaluate the effectiveness of a combination of pulsed radiofrequency and transforaminal steroid injection to the dorsal root ganglion for the treatment of postherpetic neuralgia (PHN). Patients and methods Forty-six patients suffering from thoracic PHN with a duration of between 1 and 3 months were enrolled and were randomly assigned to either steroid group (n=23) or combination group (n=23). The efficacy was assessed by visual analog scale and by recording the dose of anticonvulsant before and after the procedure. Results Visual analog scores decreased in both groups in the postintervention period (2 h, 1 week, and 1 month) with no significant difference found between them. Throughout assessments, visual analog scale in the combination group was significantly lower than in the steroid group in third and sixth months. Regarding the dosage of anticonvulsant, in the first follow-up visit 1 week from intervention, the same preintervention dose of pregabalin was prescribed and then the dose was gradually decreased until the first month in both groups. In the steroid group, the dose was increased again after the first month, while in the combination group there was a gradual decease in the dose. The dose was significantly lower in the combination group compared with the steroid group in third and sixth months. Conclusion Pulsed radiofrequency in combination with steroid injection is more effective and lasting for a longer duration than the transforaminal steroid injection alone when used for controlling of pain in patients with thoracic PHN.