Microsurgical Management of Hypoglossal Schwannomas Over 3 Decades

Abstract

The extreme lateral infrajugular transcondylar-transtubercular exposure approach, which is a modification of the extreme lateral suboccipital approach, provides sufficient exposure for most intracranial dumbbell-shaped hypoglossal schwannomas. Hypoglossal nerve reconstruction using a sural nerve graft improves tongue atrophy and movement for patients with resected nerves.

Hypoglossal Schwannoma: A Rare Case Report

“…Hypoglossal schwannomas seems to have a female predilection (2.5:1) and mean age at diagnosis was 46 years [10,16]. These figures are in accordance with our case.…”

“…The first case was reported by Slaughter et al in 1949 [9]. In a review of the literature by Cavalcanti et al in 2011, only 36 peripheral extracranial hypoglossal schwannomas were reported [16].…”

“…The clinical presentation can vary according to the site and nerve of origin. Most often, earliest feature as reported is wasting of the tongue muscles (25-94%).Hypoglossal nerve weakness is a result of expansion and streching of the nerve fibres during the tumour growth [9,10,16]. Kubota et al suggested that motor cranial nerves are more resistant to compression as they have a thick myelin sheath [17].…”

Is Hypoglossal Nerve Palsy Caused by Craniocervical Junction Degenerative Disease an Underrecognized Entity?

“…Differentiating CCJ JACs from "cystic" hypoglossal schwannomas is challenging. In a series of 44 surgically treated hypoglossal schwannomas, Nonaka et al 21 found clinical presentations similar to CCJ JACs, with a female predominance, mean patient age of 45.8 years, and symptoms including ipsilateral tongue atrophy (92%), headache (61%), and dysphagia (32%). Hypoglossal schwannomas can be characterized as intracranial (31.5%), extraand intracranial "dumbbell" (50%), or extracranial (18.5%), 22 with secondary hypoglossal canal enlargement reported in up to 83%.…”

“…Hypoglossal schwannomas can be characterized as intracranial (31.5%), extraand intracranial "dumbbell" (50%), or extracranial (18.5%), 22 with secondary hypoglossal canal enlargement reported in up to 83%. 21 So-called cystic hypoglossal schwannomas are uncommon, with cystic foci most often developing within large tumors with necrosis or spontaneous intratumoral hemorrhage. 23,24 In a previous cystic hypoglossal schwannoma case report, preoperative MR imaging showed peripheral enhancement surrounding cystic regions, whereas the tumor solid component enhanced uniformly.…”