The Greater Occipital Nerve and Its Dynamic Compression Points: Implications in Migraine Surgery

Background: The greater occipital nerve is a common compression site for migraine or chronic headache, and variable relationships with the occipital artery have been shown in anatomical studies. Despite surgical decompression, there are still a subset of patients who have an incomplete response. In this article, the authors describe an observed clear and very consistent pattern between the nerve and artery, including both dynamic and static compression points, that must be evaluated for adequate treatment. Methods: Seventy-one patients underwent occipital nerve decompression with high-definition videos and photographs, and the dynamic relationship between the greater occipital nerve and the occipital artery was recorded in a retrospective review. Results: A consistent pattern existed in 92 percent of patients, as follows: (1) hidden proximal dynamic compression of the bottom surface of the nerve as the occipital artery comes laterally to dive under the greater occipital nerve; (2) more apparent dynamic compression on the upper surface of the nerve as the occipital artery loops back on top of the greater occipital nerve; (3) intertwining compression after the bifurcation of the greater occipital nerve as the artery wraps around the medial branch; and (4) parallel travel of the terminal branch of the greater occipital nerve with the occipital artery in close proximity. Conclusions: There is a consistent pattern in the relationship between the greater occipital nerve and the occipital artery after its exit from the trapezius fascia. It is possible that this relationship creates dynamic compression points, including hidden areas, that can only be deactivated by radical excision of the vessel.