Glossopharyngeal schwannomas: A 100 year review

Abstract

Glossopharyngeal schwannomas usually present with vestibulocochlear rather than glossopharyngeal symptoms, likely due to CNVIII compression and displacement by tumor, which can be better appreciated with modern imaging. The tumor's location posterior and medial to CNVIII combined with the complex CNVIII tonotopic organization may account for the preferential mid-frequency hearing loss seen in these patients.

Letter to the Editor: Can Vagus Nerve Schwannoma Masquerade as a Carotid Chemodectoma?

“…In schwannomas of the vascular space, it is especially difficult to diagnose the nerve from which the tumor arises, and the vessels displacement is a diagnostic tool for determining which nerve root is the source of a schwannoma. In our opinion, the main differential diagnosis here would not be paraganglioma, but rather hypoglossal or glossopharyngeal schwannomas, which can displace the vessels in a similar way [3] but seem even rarer considering the sparse literature on this subject.…”

Trends in the Management of Non-Vestibular Skull Base and Intracranial Schwannomas

“…Hearing impairment is the most frequent presenting symptom in intracranial and jugular foramen LCNS. 40,41,43,47 Most of patients show a mid-frequency hearing loss, in contrast to the high-frequency hearing loss observed with VS. 47 Type A tumors may cause symptoms related to increased intracranial pressure, without or with minimal deficits of the lower cranial nerves, whereas a tumor expanding into the jugular foramen or upper cervical region might cause earlier damage of the nerves. 41 Other presenting symptoms are shown in Table 1.…”

“…40 Park et al 44 analyzed the results of surgery in 275 cases collected in large series of jugular foramen schwannomas and found postsurgical lower cranial nerve palsies in 34.9% of the patients. New neurological deficits are common, especially involving the facial nerve, which was reported in 6-34% of cases 40,43,47 Other reported complications include CSF leak (3-7%), aspiration pneumonia (1.5-6%), venous sinus thrombosis (3%), and meningitis (2%). Postoperative mortality ranges between 0.5% and 5%.…”