A patient has dysphagia, hoarseness, and asymmetric soft palate elevation. Which cranial nerve is affected, and what additional deficits might be present?

Question

This question challenges students to apply their knowledge of cranial nerve anatomy, motor functions, and clinical correlations. It requires an understanding of the vagus nerve (Cranial Nerve X) and its role in swallowing, phonation, and soft palate function.

By analyzing symptoms like dysphagia, hoarseness, and asymmetric soft palate elevation, students must identify the affected nerve and predict additional deficits, demonstrating their ability to integrate neuroanatomy with clinical reasoning.

This question is ideal for advanced Anatomy & Physiology, Neuroanatomy, or Clinical Anatomy students, especially those preparing for medical, nursing, or allied health programs.

Answer 1

The most likely affected cranial nerve is the Vagus nerve (Cranial Nerve X).

Explanation:

1. Dysphagia (difficulty swallowing) suggests impaired function of the pharyngeal muscles, which are innervated by the vagus nerve via the pharyngeal plexus.
2. Hoarseness indicates involvement of the recurrent laryngeal nerve, a branch of CN X, which controls intrinsic muscles of the larynx (except for the cricothyroid muscle).
3. Asymmetric elevation of the soft palate occurs due to paralysis of the levator veli palatini muscle, which is also supplied by the vagus nerve.

Additional Expected Deficits:

1. Deviation of the Uvula → The uvula will deviate away from the lesion due to unopposed action of the intact side.
2. Loss of Gag Reflex (Efferent Limb) → CN X provides the motor response for the gag reflex, so it would be diminished or absent.
3. Dysphonia → Weakness in vocal cord movement could lead to voice changes, making speech breathy or strained.