The Great Auricular Nerve Trigger Site: Anatomy, Compression Point Topography, and Treatment Options for Headache Pain.

Background Peripheral nerve decompression surgery can effectively address headache pain caused by compression of peripheral nerves of the head and neck. Despite decompression of known trigger sites, there are a subset of patients with trigger sites centered over the postauricular area coursing along the sulcus. The authors hypothesize that these patients experience primary or residual pain caused by compression of the great auricular nerve. Methods Anatomical dissections were carried out on 16 formalin-fixed cadaveric heads (eight female and eight male cadavers) ranging in age from 78 to 89 years. The course of the great auricular nerve was identified in the superficial cervical fascia, at the borders to the sternocleidomastoid muscle and the platysma, and within the parotid gland. Possible points of compression along fascia, muscle, and parotid gland were identified. Ultrasound technology was used to confirm these anatomical findings in a living volunteer. Results The authors' findings demonstrate that the possible points of compression for the great auricular nerve are at Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle in the dense connective tissue before entry into the parotid gland (point 2), and within its intraparotid course (point 3). The mean topographic measurements were as follows: Erb's point to the mastoid process at 7.32 cm on the right and 7.35 cm on the left, Erb's point to the angle of the mandible at 6.04 cm on the right and 5.89 cm on the left, and the posterior aspect of the sternocleidomastoid muscle to the mastoid process at 3.88 cm on the right and 4.43 cm on the left. All three possible points of compression could be identified using ultrasound. Conclusions This study identified three possible points of compression of the great auricular nerve that could be decompressed with peripheral nerve decompression surgery: Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle (point 2), and within its intraparotid course (point 3). These findings were confirmed on ultrasound in a living volunteer.