Glossopharyngeal Nerve | Cranial Nerve IX / CN IX Assessment

The glossopharyngeal (CN IX) and vagus nerve (CN X) are commonly assessed together. They primarily innervate the muscles of the tongue and pharynx, the thorax, abdominal viscera, and larynx. No diagnostic accuracy studies are available on these assessments so the clinical value is unknown. 

The patient may report having difficulties swallowing so asking the patient to take a sip on your command can be used as one assessment. You’d expect no delay or difficulty swallowing once you ask the patient to take a sip. 

Furthermore ask the patient to say “aah” with the mouth wide open and check if the uvula elevates, inspect the palate for symmetry as well.

Examine the patient’s voice and cough. A hoarse voice or bovine cough can be indicative of vagus nerve impairment due to a lack of closing of the vocal cords creating a hollow sound.

Lastly, the gag reflex can be assessed. Using a tongue depressor touch the back of the tongue on both sides and check for a gag reflex. Alternatively use a wisp of cotton and touch the soft palate.

Learn more about the assessment of all cranial nerves below:

• Cranial Nerve I: Olfactory Nerve
• Cranial Nerve II: Optic Nerve
• Cranial Nerve III: Oculomotor Nerve
• Cranial Nerve IV: Trochlear Nerve
• Cranial Nerve V: Trigeminal Nerve
• Cranial Nerve VI: Abducens Nerve
• Cranial Nerve VII: Facial Nerve
• Cranial Nerve VIII: Vestibulocochlear Nerve
• Cranial Nerve X: Vagus Nerve
• Cranial Nerve XI: Accessory Nerve
• Cranial Nerve XII: Hypoglossal Nerve

Damodaran, O., Rizk, E., Rodriguez, J., & Lee, G. (2014). Cranial nerve assessment: a concise guide to clinical examination. Clinical Anatomy, 27(1), 25-30.