National Physical Therapy Examination (NPTE) Practice Exam

Which cranial nerve is primarily involved in the dysfunction observed in trigeminal neuralgia?

1. Facial nerve (CN VII)

2. Occulomotor nerve (CN III)

3. Trigeminal nerve (CN V)

4. Glossopharyngeal nerve (CN IX)

The correct answer is: Trigeminal nerve (CN V)

Trigeminal neuralgia is primarily associated with dysfunction of the trigeminal nerve, which is cranial nerve V. This condition is characterized by episodes of intense, sharp facial pain that can occur spontaneously or be triggered by activities such as eating, speaking, or touching the face. The trigeminal nerve is responsible for sensation in the face and also controls some muscles involved in chewing. When this nerve is compressed or irritated, often due to vascular compression or other anatomical factors, it leads to the symptoms characteristic of trigeminal neuralgia. The other cranial nerves listed do not play a direct role in this condition. For instance, the facial nerve is primarily involved in facial muscle movements and taste sensations from the anterior two-thirds of the tongue, while the oculomotor nerve primarily controls eye movements and pupil constriction. The glossopharyngeal nerve is involved in taste from the posterior one-third of the tongue and innervates muscles for swallowing. While these nerves have their own significant roles in facial and head function, they are not implicated in the pathophysiology of trigeminal neuralgia.