What is a common symptom of damage to Cranial Nerve XI?

Damage to Cranial Nerve XI, also known as the accessory nerve, primarily affects the sternocleidomastoid and trapezius muscles. A common symptom of such damage is weakness or inability to shrug the shoulder on the affected side. The trapezius muscle is responsible for elevating the shoulder girdle, so when this nerve is compromised, the strength needed for shoulder elevation is diminished.

This nerve also innervates the sternocleidomastoid muscle, which aids in turning the head. Weakness in shoulder shrug can be particularly noticeable during tasks that require lifting or stabilizing the shoulder, giving a clear indication of the nerve's injury.

The other answer choices pertain to different cranial nerves and their functions. For instance, unilateral paralysis of the tongue is associated with damage to Cranial Nerve XII (hypoglossal nerve), while the loss of taste on the posterior third of the tongue is related to Cranial Nerve IX (glossopharyngeal nerve). Deviated jaw to the opposite side typically reflects an issue with Cranial Nerve V (trigeminal nerve), particularly its mandibular branch. Thus, weakness in shrugging the ipsilateral shoulder is distinctly identified with the dysfunction of Cranial N