Injury of accessory nerve, right side, initial encounter

This code signifies damage to the right accessory nerve (cranial nerve XI), which primarily controls the sternocleidomastoid and trapezius muscles. Such an injury can result in weakness or paralysis of shoulder shrugging, head rotation, and arm elevation. It represents the initial phase of treatment for this specific nerve injury.

Apply this code when documentation clearly indicates a new, acute injury to the right accessory nerve, such as from trauma, surgery, or compression. Supporting documentation should include a neurological exam detailing deficits in the sternocleidomastoid and/or trapezius muscles on the right side, consistent with accessory nerve dysfunction.

• Ensure laterality (right side) is explicitly documented.
• Confirm this is the initial encounter for treatment; subsequent encounters will use different seventh characters.
• Differentiate from brachial plexus injuries, which involve multiple nerves and have distinct codes.