Disorders of cranial nerves IX and X.

The glossopharyngeal and vagus nerves mediate the complex interplay between the many functions of the upper aerodigestive tract. Defects may occur anywhere from the brainstem to the peripheral nerve and can result in significant impairment in speech, swallowing, and breathing. Multiple etiologies can produce symptoms. In this review, the authors broadly examine the normal functions, clinical examination, and various pathologies of cranial nerves IX and X.