Injury to accessory nerve

This code signifies damage or trauma to the accessory nerve (cranial nerve XI). This injury can result in impaired function of the sternocleidomastoid and trapezius muscles, leading to issues with shoulder elevation, head rotation, and neck movement.

Apply this code when documentation explicitly states an injury to the accessory nerve, such as from a penetrating wound, surgical complication, or blunt trauma. It is appropriate for both acute and chronic presentations of accessory nerve damage.

• Ensure the documentation specifies "injury" to the accessory nerve, not just a symptom like shoulder weakness, which could have other etiologies.
• Distinguish from other cranial nerve injuries; confirm the specific nerve affected is the accessory nerve.
• Consider an external cause code (E-code) to describe the circumstances of the injury, if known and documented.