Background: The most common cause of a spinal accessory nerve (SAN) lesion is iatrogenic injuries that occur during operations on the posterior cervical triangle of the neck. Dorsal scapular nerve (DSN) lesions occur rarely and are usually caused by compression of the nerve by the hypertrophic middle scalene muscle or stretching of the nerve as a result of traumatic movements. Case Presentation: We present a case with SAN and DSN lesions due to neck surgery because it is a rare case and we think it will contribute to the literature. To the best of our knowledge, this is the first presentation of a case of iatrogenic injury to both the SAN and DSN. As a result of the examination and evaluation by ultrasonography of the patient, we suspected the accompanying DSN lesion and confirmed it with electromyography (EMG) examination. Conclusion: Musculoskeletal ultrasound can be used as an assistive or alternative technique for EMG examination in the diagnosis of chronic peripheral nerve lesions by measuring muscle thickness.

Keywords: Electromyography; peripheral nerve injuries; winged scapula; ultrasound; muscle thickness; case report