A patient has been diagnosed with strep throat. The nurse is aware that without treatment, which complication may occur?

A. XI: Cranial nerve XI, also known as the accessory nerve, is responsible for innervating the sternocleidomastoid and trapezius muscles, which are involved in shoulder and head movement. It does not play a role in tongue movement.

B. V: Cranial nerve V, the trigeminal nerve, is responsible for sensation in the face and motor functions such as biting and chewing. While it is important for overall oral sensation, it does not control tongue movement.

C. XII: Cranial nerve XII, the hypoglossal nerve, is responsible for motor control of the tongue muscles. When the patient sticks out their tongue, the nurse can assess the function of this nerve by observing the tongue's position, movement, and any signs of weakness or atrophy, which can indicate nerve damage.

D. VII: Cranial nerve VII, the facial nerve, is responsible for the muscles of facial expression and taste sensations from the anterior two-thirds of the tongue. Although it contributes to some oral functions, it is not directly involved in the movement of the tongue itself.

A. Nystagmus in extreme superior gaze: A few beats of nystagmus in extreme lateral gaze may be normal, but sustained nystagmus, especially in superior gaze, suggests neurological impairment such as vestibular dysfunction or multiple sclerosis.

B. Slight amount of lid lag when moving the eyes from a superior to an inferior position: Lid lag, where the upper eyelid lags behind the downward movement of the eye, is often associated with hyperthyroidism (e.g., Graves' disease). It is not a normal finding in the diagnostic positions test.

C. Convergence of the eyes: Convergence is assessed when a person focuses on a near object, such as during an accommodation test. The diagnostic positions test evaluates extraocular muscle function and cranial nerves III, IV, and VI, focusing on coordinated movement rather than convergence.

D. Parallel/synchronized movement of both eyes: The normal finding in the diagnostic positions test is smooth, coordinated movement of both eyes in all six cardinal directions without lagging, misalignment, or significant nystagmus. This indicates intact extraocular muscles and proper cranial nerve function.