A Newly Discovered Frontotemporal Nerve: Implications in Treatment of Migraine Headache and Migraine Surgery

BACKGROUND: Migraine headaches are a debilitating disease affecting 37 million people, with an incidence of 18% for women and 6% of men. Due to incomplete efficacy of traditional medications, patients often seek more invasive treatments. 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. However, some patients who undergo surgery still have residual pain. Up to 17.8% of patients have emergence of pain at a secondary site postoperatively. A theory to explain incomplete surgical outcome is failure to identify and release unknown culprit nerves. In our experience doing frontal nerve decompression on migraine patients, we noticed a previously undescribed accessory nerve in the frontotemporal area. This study reports the incidence and location of this nerve. METHODS: A retrospective review of 103 patients who underwent migraine decompression surgery at UT Southwestern was done. 27 patients were excluded, as they did not undergo frontal site decompression and the area was not visualized. For the included 76 patients, measurements of this nerve had been taken intraoperatively using high-definition endoscopic assistance. RESULTS: Of the original 103 patients reviewed, 76 patients had received frontal endoscopic decompression. Of that group, 56 were female. This frontotemporal nerve was present in 55%, and bilateral incidence was 57%. An accompanying vessel was also present 81% of the time. Both nerve and vessel varied in size. 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 avulsion of this nerve may result in a better surgical response rate. Additionally, this nerve should be considered during nerve block and onabotulinum toxin injections to improve outcome and accuracy. A review of available anatomical textbooks and current literature did not yield a nerve similar to the one described here. Our description of this newly discovered nerve may have implications for other anatomical and surgical uses.