title: Efficacy of pulsed radiofrequency in the treatment of thoracic postherpetic neuralgia from the angulus costae: a randomized, double-blinded, controlled trial.
abstract: BACKGROUND
  Postherpetic neuralgia (PHN) is often refractory to existing treatments. Pulsed radiofrequency (PRF) is known to be effective for treating neuropathic pain. In common, the targets of PRF treatment were the segmental dorsal root ganglion (DRG) neurons responsible for the pain. A potential complication that can occasionally occur with PRF treatment is damage to the adjacent tissue and organ. The effectiveness of the angulus costae as a puncture site for PRF has not been tested in thoracic PHN treatment.
  
  
  OBJECTIVE
  The goal of this study was to investigate the therapeutic efficacy and safety of PRF for treating thoracic PHN through the puncture of the angulus costae.
  
  
  METHODS
  Prospective, randomized, double-blinded study.
  
  
  METHODS
  Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine.
  
  
  METHODS
  Ninety-six patients with thoracic (T2-11) PHN were equally randomized assigned into 2 groups. The electrode needle punctured through the angulus costae of each patient guided by x-ray; PRF at 42° C for 120 seconds was applied after inducing paresthesia involving the affected dermatome area. PRF was applied in the PRF group (n = 48) twice. It was also applied in the sham group (n = 48) twice without radiofrequency energy output. The treatment was done once a week for 3 weeks. Tramadol was used for flare pain when the visual analog scale (VAS) ≥ 3.
  
  
  METHODS
  The therapeutic effect was evaluated by VAS, SF-36 health survey questionnaire, side effects (type, frequency, and onset time) before treatment, at days 3, 7, and 14, and at months one, 2, 3 and 6 after PRF. The average of tramadol (mg/d) administered within the first  month after treatment was also recorded.
  
  
  RESULTS
  The postprocedure VAS scores in the PRF group were significantly lower than those in the sham group and lasted for 6 months after treatment (P < 0.05). The SF-36 score, such as physical functioning, physical role, bodily pain, general health perceptions, social function, emotional role, and mental health index were significantly improved until 6 months after treatment in the PRF group compared to the sham group (P < 0.01-0.05). The average dosage of tramadol  administrated (mg/d) within the first  month after treatment was also significantly reduced in the PRF group compared to the sham group (P < 0.05). There were no obvious signs of pneumothorax, bleeding, infection, or other severe side effects in either group (P > 0.05).
  
  
  CONCLUSIONS
  Single center study, relatively small number of patients.
  
  
  CONCLUSIONS
  The strategy that the angulus costae be used as the PRF puncture point of an electrode needle and the final localization of the needle tip as determined by sensory testing is an effective and safe therapeutic alternative for thoracic PHN treatment. Benefits include that the procedure is minimally invasive, provides short-term pain relief, and improves quality of life.
  
  
  BACKGROUND
  NO ISRCTN25588650.
authors: Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine,  Shanghai, 20092, China.
authors: Ma
authors: M
authors: Ke
authors: Fan
authors: F
authors: Yinghui
authors: Jin
authors: J
authors: Yi
authors: Huang
authors: H
authors: Xeuhua
authors: Liu
authors: L
authors: Xiaoming
authors: Cheng
authors: C
authors: Zhijun
authors: Huang
authors: H
authors: Chao
authors: Wang
authors: W
authors: Yingwei
mesh_terms: D000368:Aged; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D051474:Neuralgia, Postherpetic / Q000628:therapy*; D010147:Pain Measurement; D061208:Pulsed Radiofrequency Treatment / Q000379:methods*; D013909:Thorax