Neurotologic considerations in the treatment of advanced clival tumors

Head and neck manifestations of advanced clival tumors result from subtle, yet progressive mass effect or direct involvement of multiple cranial nerves. Misinterpretation of clinical or radiographic findings in these patients may result in inappropriate treatment planning, increased patient morbidity, and probable tumor recurrence. Our combined experience in managing 21 patients with advanced clival tumors has shown that preoperative loss of vision, diplopia, or facial hypesthesia suggests superior parasellar disease. Facial twitching or neurotologic symptoms result from posterior central tumor growth, while inferior extension of disease leads to basal cranial nerve deficits with associated speech, voice, and swallowing dysfunctions. The purpose of this article is to correlate the complex anatomy of the clivus, brainstem, and cranial base and the various neurotologic findings associated with neoplasms in this region. Lateral skull base surgical procedures, based on preoperative clinicoradiographic assessment, will be detailed with particular emphasis on preservation of critical neurovascular structures.