The Great Auricular Point: A Landmark for Safe Sternocleidomastoid Myotomy in Selective Cervical Denervation for Cervical Dystonia.

[BACKGROUND AND OBJECTIVES] Cervical dystonia is the most common focal dystonia, characterized by involuntary muscle contractions leading to abnormal postures and significant discomfort. Although neuromuscular blockade with botulinum toxin and other agents is the primary treatment, selective cervical denervation, which includes sternocleidomastoid (SCM) and posterior cervical muscle denervation, is a surgical option for refractory cases. The aim of this study was to evaluate the great auricular point (GAP) as a reliable intraoperative landmark for selective cervical denervation, optimizing spinal accessory nerve (SAN) preservation during SCM myotomy/denervation.

[METHODS] A review of anatomic studies and cadaveric dissections was conducted to assess the GAP's role in guiding safe SCM myotomy and minimizing SAN injury. The anatomic relationship between the GAP, SAN, and great auricular nerve was evaluated for consistency. Subsequently, this technique, including denervation of the accessory nerve branches to SCM, was applied clinically in 5 patients.

[RESULTS] We report a modification of selective cervical denervation using the GAP technique during SCM myotomy and selective denervation. The GAP was consistently located inferior to the SAN exit site at the posterior SCM border. Shoulder motion and scapular stability were maintained in all 5 patients. The GAP provided a stable reference point for SCM myotomy, effectively preserving the SAN's trapezius branch and enhancing surgical precision.

[CONCLUSION] The GAP serves as a reliable intraoperative landmark for selective cervical denervation, facilitating safe SCM myotomy and minimizing iatrogenic SAN injury. In addition, this technique may minimize revisions by providing enhanced visibility and precision during SCM myotomy. Further clinical validation is warranted to confirm its broader efficacy in neurosurgical practice.