Objectives: Transforaminal epidural injection (TFEI) has superior accessibility to the dorsal root ganglion, which is an essential location of pain signaling in herpes zoster. However, the effectiveness of TFEI for herpes zoster patients has not previously been studied. We retrospectively analyzed the efficacy of TFEI for pain control and prevention of PHN in patients with acute and subacute herpes zoster.
Methods: Medical records of 137 patients who underwent TFEI for zoster-associated pain (ZAP) were reviewed. The participants were divided into two groups: acute TFEI group (TFEI within 30 days after zoster) and subacute TEEI group (TFEI between 30 and 90 days). The efficacy of TFEI was assessed by a numerical rating scale (NRS), doses of medications, and time to relief of ZAP. Incidence of PHN at 1 week to 6 months after TFEI was evaluated.
Results: Time to ZAP relief was significantly shorter and the incidence of PHN was significantly lower in the acute TFEI group than in the subacute TFEI group. Rate of medication discontinuation was significantly higher in the acute TFEI group than in the subacute TFEI group.
Conclusions: Early application of TFEI in the acute phase of zoster can be a useful option for ZAP control and prevention of chronic neuropathic pain such as PHN.
Keywords: Epidural; Herpes zoster; Postherpetic neuralgia; Transforaminal.