Case Report-Successful Treatment of Brush-evoked Pain Induced after Herpes Zoster by Trigger Point Injections with Botulinum Toxin A

Abstract

Postherpetic neuralgia (PHN) is a common peripheral neuropathic pain syndrome. Current treatments for neuropathic pain include pharmacological and non-pharmacological management. Non-pharmacological treatments which are not the mainstay therapeutic options should be considered to manage subtypes of patients who are refractory to medications or intolerant of the side effects of drugs. Herein, we report a 58 year-old female patient suffered from persistence of pain symptoms involving the right forth to seventh cervical roots for 4 months. The pain didn't respond well to low-dose medications. She was intolerant of the side effects of high-dose drugs. Physical examinations revealed both brush-evoked pain and myofascial trigger points on her neck, shoulder and upper arm. The pain manifestations of her PHN were comprised of sensory neuralgia and myofascial pain. Analgesic properties of Botulinum toxin A (BTX-A) have demonstrated to be beneficial in myorelaxation and have multiple effects on the sensory nervous system. Therefore, we used trigger point blocks with BTX-A once to relieve her pain successfully without recurrence of pain during the one year follow up. To our knowledge, this is the first case of brush-evoked pain induced after herpes zoster combined with myofascial pain successfully treated by trigger point injections with BTX-A. Furthermore, the duration of pain-free time compared to intradermal or subcutaneous injections was substantially greater. However,further large-scale studies are needed to replicate this clinical observation.