Background

 Postherpetic neuralgia (PHN) is a painful complication of acute herpes zoster. However, treatment of  intractable PHN remains clinically challenging because both peripheral and central pathophysiological mechanisms contribute to PHN pain. Peripheral nerve block with local anesthetics have been used in the treatment of neuralgia and can provide pain relief in region supplied by blocked nerve. Recently pectoral nerve (Pecs) Ⅱ block was reported a simple interventional procedure that produces good analgesia for breast surgery. 

Case report

 An 82-year-old man visited our pain clinic with chronic chest pain around left nipple. Over the past few decades he had received several medications and interventional treatments, including radiofrequency ablation, epidural block and paravertebral block at other clinics. Although spontaneous pain, intensity and distribution of the pain had diminished gradually, the localized allodynia around nipple was remained. We performed ultrasound guided Pecs Ⅱ block with 20 ml of 0.2% ropivacaine between pectoralis minor and serratus anterior. His pain relief scale was 70~80% reduction after the procedure. This symptom relief was maintained continuously following repeated Pecs Ⅱ blocks were conducted at 1-week intervals.   

Discussion

 We reported a patient with localized intractable thoracic PHN
who did not respond to various treatments, but in whom the
ultrasound guided Pecs Ⅱ block induced symptom
improvement.
Peripheral nerve block may be used as an alternative option for localized peripheral neuropathic pain treatment because irritable peripheral nociceptor contribute to pain mechanism of PHN. 
 In Pecs Ⅱ block, local anesthetic has to be spreaded 
between pectoralis minor and serratus anterior. Pecs Ⅱ block
which blocks thoracic intercostal nerve from T2-T6, long
thoracic nerve and thoracodorsal nerve is useful in localized 
pain around nipple. We suggest ultrasound guided Pecs Ⅱ block can be considered as an alternative treatment of
intractable localized anterior chest wall pain associated with
PHN. 
References
 
1. Fields HL, Rowbotham M, Baron R. Postherpetic neuralgia: irritable nociceptors and deafferentation. Neurobiol Dis 1998;5:209-27.
2. Bashandy GM, Abbas DN. Pectoral nerves Ⅰ and Ⅱ blocks in multimodal analgesia for breast cancer surgery: a randomized clinical trial. Reg Anesth Pain Med 2015;40:68-74.
3. Vlassakov KV, Narang S, Kissin I. Local anesthetic blockade of peripheral nerves for treatment of neuralgias: systematic analysis. Anesth Analg. 2011;112:1487-93.

Ultrasound guided pectoral nerve &#8545; block for intractable thoracic postherpetic neuralgia

Ultrasound guided pectoral nerve Ⅱ block for intractable thoracic postherpetic neuralgia