Glossopharyngeal and Vagus Nerve

The 9th and 10th nerves are tested together. They are responsible for swallowing, phonation, guttural and palatal articulation (the 7th nerve has a component for labial articulation). The glossopharyngeal nerve also subserves taste to the posterior one-third of the tongue but this is rarely tested.

Examination Technique:

  • check palatial elevation by having the patient sustain an “ah.” When observing palatal movement, look at the palate rather than the uvula.
  • assess the gag reflex by gentling stroking the soft palate on each side.
  • swallowing can be assessed by giving the patient a sip of water and observing them swallow.
  • listen to the patient’s speech. Is there a nasal quality?
  • assess palatal articulation with a “KA” sound, guttural with a “GO” sound and labial with a “PA” sound.

Normal Response:
the palate should elevate symmetrically, both when sustaining an “AH” and in response to stimulation on either side. Some patients however do not have a gag response and this can be normal if it is absent bilaterally. Patients should also be asked if they feel the stimulus.

Abnormal Response:
with unilateral palatal weakness, the palate fails to elevate on the weak side and the gag reflex will be absent on that side.

Glossopharyngeal and Vagus Nerve