FUNCTION -- Motor Control of Gag Response and Speech

TEST I -- Ahh!!!
The patient should utter a prolonged "AAAAAAAAHHHHHHHHH." This should cause the tongue to flatten, thereby revealing a symmetrically rising soft palate with posterior and upward movement of the uvula along the midline. Click here to see inside the mouth during this test.

INTERPRETATION
The unilateral failure of the soft palate to rise accompanied by a contralaterally deviating uvula may indicate a unilateral vagal nerve palsy. Bilateral damage may be expressed as a bilateral motoric deficit in this domain. Often accompanying the vagal nerve palsy will be dysarthria and hoarseness of the voice. Normal responses on this test accompanied by diminished gag responses implicating defects involving cranial nerve IX. Diminished responses on this test coupled with impaired gag responses may reflect damage involving cranial nerve X in isolation (as it is responsible for much of the motoric component of the gag response) or in combination damage to cranial nerve IX. Dysarthric conditions may also arise consequent to damage to higher centers.