title: Ultrasound-guided greater occipital nerve block for patients with occipital headache and short term follow up.
abstract: BACKGROUND
  The greater occipital nerve (GON) block has been frequently used for different types of headache, but performed with rough estimates of anatomic landmarks. Our study presents the values of the anatomic parameters and estimates the effectiveness of the ultrasound-guided GON blockade.
  
  
  METHODS
  The GON was detected using ultrasound technique and distance from external occipital protuberance (EOP) to GON, from GON to occipital artery and depth from skin to GON was measured in volunteers. Patients with occipital headache were divided into two groups (ultrasound-guided block: group S, conventional blind block: group B) and GON block was performed. The same parameters were measured on group S and VAS scores were assessed at pretreatment, 1 week and 4 weeks after treatment on both groups.
  
  
  RESULTS
  The GON had distance of 23.1 ± 3.4 mm (right) and 20.5 ± 2.8 mm (left) from EOP to GON. Its depth below the skin was 6.8 ± 1.5 mm (right) and 7.0 ± 1.3 mm (left). The distance from GON to occipital artery was 1.5 ± 0.6 mm (right) and 1.2 ± 0.6 mm (left) in volunteers. Initial VAS score of group S and group B patients were 6.4 ± 0.2 and 6.5 ± 0.2. VAS score of 4 weeks after injection were 2.3 ± 0.2 on group S and 3.8 ± 0.3 on group B (P = 0.0003).
  
  
  CONCLUSIONS
  The parameters measured in this study should be useful for GON block and ultrasound-guided blockade is likely to be a more effective technique than blind blockade in occipital headache treatment.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Jae Hang
authors.initials: JH
authors.lastname: Shim
authors.forename: So Young
authors.initials: SY
authors.lastname: Ko
authors.forename: Mi Rang
authors.initials: MR
authors.lastname: Bang
authors.forename: Woo Jae
authors.initials: WJ
authors.lastname: Jeon
authors.forename: Sang Yun
authors.initials: SY
authors.lastname: Cho
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Yeom
authors.forename: Woo Jong
authors.initials: WJ
authors.lastname: Shin
authors.forename: Kyoung Hun
authors.initials: KH
authors.lastname: Kim
authors.forename: Jae-Chol
authors.initials: JC
authors.lastname: Shim