Does the palate elevate symmetrically when the patient says, "Aah"? Does the patient gag when the posterior pharynx is brushed? The gag reflex needs to be tested only in patients with suspected brainstem pathology, impaired consciousness, or impaired swallowing.
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Palate elevation and the gag reflex are impaired in lesions involving CN IX, CN X, the neuromuscular junction, or the pharyngeal muscles.