Accessory Nerves of the Forehead. A Newly Discovered Frontotemporal Neurovascular Bundle and its Implications in the Treatment of Migraine Headache, Migraine Surgery, and Cosmetic Temple Filler Injection

Background: Surgical decompression of peripheral cranial and spinal nerves at several anatomically studied trigger sites has demonstrated significant efficacy in bringing permanent relief to migraine sufferers. In our experience doing frontal nerve decompression on migraine patients, we noticed a previously undescribed accessory nerve and vessel in the frontotemporal area, and report its implication in migraine surgery and cosmetic filler injection. Methods: A retrospective review of 113 patients who underwent frontal migraine decompression surgery at UT Southwestern from July 2011 to May 2016 was done. For the included 76 patients, measurements of this nerve had been taken intraoperatively using high-definition endoscopic assistance and topographic measurements where correlated with endoscopic location of the nerve. Results: This frontotemporal nerve was present in 55%, and bilateral incidence was 57% of those. An accompanying vessel was also present in 81% of nerve complexes. Both nerve and vessel varied in size. A large vessel was present in 8% of all patients, and a medium vessel in 20%. Consistently, the nerve exited a foramen in the frontal bone on average 3.4 cm (SD = 0.47 cm) superior to the lateral canthus. Conclusion: The identification and proper avulsion neurectomy of this newly described sensory frontotemporal nerve may lead to better surgical response rate during migraine surgery. Additionally, this nerve should be considered during nerve block and botulinum toxin injections in migraine treatment. The existence of the accompanying vessel could have significant implications in the safety of filler and fat injections to this area. Financial Disclosure Statement: The authors have no financial interests in this research project or in any of the techniques or equipment used in this study. Presented at : 1- 55th Annual Medical Student Research Forum: 2017 Jan 17; Dallas, TX Corresponding author: Bardia Amirlak, M.D.F.A.C.S,, Department of Plastic Surgery, University of Texas Southwestern Medical Center, 1801 Inwood Road, Dallas, TX 75390-9132, E-mail: Bardia.Amirlak@UTSouthwestern.edu ©2018American Society of Plastic Surgeons