title: Ultrasound-Guided Cervical Nerve Root Block: Does Volume Affect the Spreading Pattern?
abstract: Ultrasound-guided cervical nerve root block (US-CRB) is considered a safe and effective method for the treatment of radicular pain. However, previous studies on the spreading pattern of injected solution in US-CRB have reported conflicting results. The aim of this study was to investigate the spreading pattern in relation to injection volume.
  
  
  
  An institutional, prospective case series.
  
  
  
  A university hospital.
  
  
  
  Fifty-three patients diagnosed with mono-radiculopathy in C5, 6, or 7.
  
  
  
  US-CRB with fluoroscopic confirmation was performed. After the cervical roots were identified in ultrasound imaging, a needle was gently introduced toward the posterior edge of the root using an in-plane approach. The spread of 1 mL and 4 mL contrast medium, each injected in the same needle position, was examined with anteroposterior and lateral fluoroscopic views. After contrast injection, a mixture of local anesthetic and corticosteroid was injected. Clinical outcome was assessed using a numeric rating scale before and 2 weeks after the procedure.
  
  
  
  Contrast medium did not spread into the epidural space in any patients with 1 mL contrast medium injection, but it did spread into the intraforaminal epidural space in 13 patients (24.5%) with 4 mL. Pain improved in all patients. There was no significant difference in pain relief according to the spreading pattern.
  
  
  
  The spreading pattern of injected solution in US-CRB could be partially affected by the injectant volume. However, further studies are needed to assess the importance of other factors, such as needle position and physiological effects.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Seung Nam
authors.initials: SN
authors.lastname: Yang
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Se Hwa
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Chan Woo
authors.initials: CW
authors.lastname: Byun
authors.affiliation: Department of Physical Medicine and Rehabilitation, Korea University Guro Hospital, Seoul, Korea rehab46@korea.ac.kr.
authors.forename: Joon Shik
authors.initials: JS
authors.lastname: Yoon
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D011843:Radiculopathy / Q000000981:diagnostic imaging* / Q000188:drug therapy; D013126:Spinal Nerve Roots / Q000000981:diagnostic imaging* / Q000187:drug effects; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Cervical; Radiculopathy; Selective Nerve Root Injection; Spreading Pattern; Ultrasound