Common cranial nerve examination questions for medical finals, OSCEs and MRCP PACES: glossopharyngeal (IX), vagus (X) and hypoglossal nerves (XII)
Click on the the questions below to see the answers, or click here for questions about other cranial nerves and click here to learn how to examine the cranial nerves.
Which way does the tongue deviate in a XII nerve lesion?
- The tongue deviates towards the side of the lesion
Which way does the uvula deviate in a X nerve lesion?
- Uvula is deviated away from the side of the lesion.
What are the afferent and efferent pathways of the gag reflex?
- Afferent: Glossopharyngeal (IX)
- Efferent: Vagus (X)
What are clinical signs of cavernous sinus syndrome?
- Unilateral III, IV, V1, VI dysfunction
What is Lateral Medullary Syndrome?
- Clinical syndrome of symptoms caused by infarction of the lateral medulla and the inferior surface of the cerebellum due to occlusion of the posterior inferior cerebellar artery (PICA).
What are the clinical signs of an ipsilateral Lateral medullary syndrome?
- Ipsilateral Horner’s syndrome
- Ipsilateral Cerebellar signs
- Ispilateral V (facial numbness), IX (diminished gag reflex), X (palatal paralysis) and XI (weak sternocleidomastoid) nerve signs
- Contralateral spinothalamic signs (below the lesion)
- Crossing of weakness/sensory changes are highly suggestive of unilateral brainstem disorder as crossing of the spinothalamic (sensory) and pyramidal tracts (motor) occur below the brainstem, at the medulla.
- A common cause of lateral medullary syndrome is due to occlusion of, commonly, the posterior inferior cerebellar artery or vertebral artery.
- XII is not usually affected as the nucleus is found more medially.
How to perform the cranial nerve exam for doctors, medical students, finals, OSCEs and PACES