Interventional Treatments for Postherpetic Neuralgia: A Systematic Review

Abstract

Background: Postherpetic neuralgia, a persistent pain condition often characterized by allodynia and hyperalgesia, is a deleterious consequence experienced by patients after an acute herpes zoster vesicular eruption has healed. The pain associated with postherpetic neuralgia can severely affect a patient’s quality of life, quality of sleep, and ability to participate in activities of daily living. Currently, first-line treatments for this condition include the administration of medication therapies such as tricyclic antidepressants, pregabalin, gabapentin, and lidocaine patches, followed by the application of tramadol and capsaicin creams and patches as second- or third-line therapies. As not all patients respond to such conservative options, however, interventional therapies are valuable for those who continue to experience pain. Objective: This review focuses on interventional therapies that have been subjected to randomized controlled trials for the treatment of postherpetic neuralgia, including transcutaneous electrical nerve stimulation; local botulinum toxin A, cobalamin, and triamcinolone injection; intrathecal methylprednisolone and midazolam injection; stellate ganglion block; dorsal root ganglion destruction; and pulsed radiofrequency therapy. Study Design: Systematic review Setting: Hospital department in Taiwan Methods: Search of PubMed database for all randomized controlled trials regarding postherpetic neuralgia that were published before the end of May 2017. Results: The current evidence is insufficient for determining the single best interventional treatment. Considering invasiveness, price, and safety, the subcutaneous injection of botulinum toxin A or triamcinolone, transcutaneous electrical nerve stimulation, peripheral nerve stimulation, and stellate ganglion block are recommended first, followed by paravertebral block and pulsed radiofrequency. If severe pain persists, spinal cord stimulation could be considered. Given the destructiveness of dorsal root ganglion and adverse events of intrathecal methylprednisolone injection, these interventions should be carried out with great care and only following comprehensive discussion. Limitations: Although few adverse effects were reported, these procedures are invasive, and a careful assessment of the risk-benefit ratio should be conducted prior to administration. Conclusion: With the exception of intrathecal methylprednisolone injection for postherpetic neuralgia, the evidence for most interventional procedures used to treat postherpetic neuralgia is Level 2, according to “The Oxford Levels of Evidence 2”. Therefore, these modalities have received only grade B recommendations. Despite the lack of a high level of evidence, spinal cord stimulation and peripheral nerve stimulation are possibly useful for the treatment of postherpetic neuralgia. Key words: Interventional treatment, postherpetic neuralgia, botulinum toxin, steroid, stellate ganglion block, peripheral nerve stimulation, paravertebral block, radiofrequency, spinal cord stimulation

The Association between Herpes Zoster and Increased Cancer Risk: A Nationwide Population-Based Matched Control Study

“…The secondary outcome was the comparison of the incidence of specific cancers by follow-up time interval between the PHN (presence of PHN in the HZ group) and non-PHN groups (absence of PHN in the HZ group). PHN was defined as persistent chronic pain of >3 months after the diagnosis of HZ [ 29 ].…”

The effect of subcutaneous injection of methylprednisolone acetate and lidocaine for refractory postherpetic neuralgia: a prospective, observational study

“…With regard to the interventional procedures for the treatment of PHN patients, the results of a systematic review indicated that most of them were recommended as grade B because of the absence of a high level of evidence except for intrathecal methylprednisolone injection, but this intervention should be only conducted with great caution and careful comprehensive assessment. 4 Currently, in Vietnam, conventional regimens including anticonvulsants (gabapentin and pregabalin), tricyclic antidepressants (amitriptyline and nortriptyline), topical agents (5% lidocaine patch), and tramadol (in combination with acetaminophen) are available and acceptable for treatment patients with PHN. All patients who prior to being recruited into our research had been tried for treatment with the abovementioned drugs in other hospitals, but they showed a treatment failure.…”

“…The mixture of corticosteroids and local anesthetics has been broadly used to treat numerous disorders with neuropathic pain, including treatment and prevention of HZ and PHN, 4,10,11,[28][29][30][31] but to our best knowledge, this is the first time a combination of injectable methylprednisolone and lidocaine have been administered for treating refractory PHN. In the literature, we found a small number of studies with other options to manage this condition.…”

“…It is also frequently accompanied by allodynia (pain from usually nonnoxious stimuli) and/or hyperalgesia (increased response caused by stimuli that normally provoke pain). 3,4 The negative impacts on patients' activities of daily living and health-related quality of life (HRQOL) may be devastating. 5 It affects not only physical but also functional and psychological health of the patients and even spouses and relatives.…”

Efficacy of Electroacupuncture Therapy in Patients With Postherpetic Neuralgia: Study Protocol for a Multicentre, Randomized, Controlled, Assessor-Blinded Trial

“…Although multiple kinds of therapies have been adopted to treat PHN, the efficacy of conventional therapies (e.g., medication, local anesthesia, surgical operations) remains unsatisfactory because many of these therapies can cause side effects leading to patient intolerance (4). In addition, many of these therapies are not applicable to all patients with PHN and some patients have high-risk for recurrence.…”