1. The spinal accessory nerve continues alone and heads backwards and downwards. 2. Optional motor donor nerves are : the masseteric nerve, accessory nerve or hypoglossal nerve. 3. Traditional descriptions of the accessory nerve divide it into a spinal part and a cranial part. 4. Injury to the accessory nerve can result in neck pain and weakness of the trapezius muscle. 5. A winged scapula due to spinal accessory nerve damage will often be exaggerated on arm abduction. 6. Damage to the accessory nerve ( XI ) will lead to ipsilateral weakness in the trapezius muscle. 7. A winged scapula may also be suggestive of abnormal spinal accessory nerve function, as described above. 8. These include the carotid and in some instances the three structures-IJV, SCM and Accessory Nerve . 9. Injury to the spinal accessory nerve is most commonly caused by medical procedures that involve the head and neck. 10. The "'accessory nerve "'is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles.