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.