TY - JOUR T1 - CT-Guided Injection of the Anterior and Middle Scalene Muscles: Technique and Complications JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. DO - 10.3174/ajnr.A2319 AU - A. Mashayekh AU - P.J. Christo AU - D.M. Yousem AU - J.J. Pillai Y1 - 2011/01/13 UR - http://www.ajnr.org/content/early/2011/01/13/ajnr.A2319.abstract N2 - BACKGROUND AND PURPOSE: Anterior scalene block is a helpful diagnostic test for NTOS and a good predictor of surgical outcome. The purpose of this study was to describe the technique, success rate, and complications associated with CT-guided anesthetic and botulinum toxin injection of the ASM/MSM in patients with NTOS symptoms. MATERIALS AND METHODS: One hundred six participants (mean age, 41.5 ± 10 years; 80 women) were identified via a retrospective review of medical records for CT-guided scalene blocks. The procedure was evaluated regarding the technical success, defined as satisfactory detection of the ASM/MSM; intramuscular needle placement; intramuscular injection of contrast; appropriate delivery of medication; and frequency of unintended BP block or other complications. We also determined the outcome of patients who underwent surgery following the block. RESULTS: Study participants underwent 146 scalene injections, 83 blocks, and 63 chemodenervations, which were included in this investigation. In all cases, detection of the ASM/MSM and intramuscular needle placement was satisfactory. Postprocedural complications included 5 (3.4%) temporary BP blocks, 1 patient with (0.7%) Horner sign, 7 (4.8%) needle-induced pain reports, 1 (0.7%) case of dysphagia, and 2 (1.4%) instances of muscle weakness. There were no major complications reported. The rate of good outcome following surgery was the same in patients with positive versus negative blocks, 30/43 (70%) versus 5/7 (71%), respectively. CONCLUSIONS: CT guidance is a useful adjunct in performing accurate ASM/MSM blocks with a low rate of minor complications. ER -