Hypoglossal schwannomas: A systematic review of the literature

J Clin Neurosci. 2019 Apr:62:162-173. doi: 10.1016/j.jocn.2018.11.037. Epub 2018 Nov 22.

Abstract

Background: Schwannomas of the hypoglossal nerve are rare and account for a very small percentage of non-vestibular schwannomas.

Objectives: In this systematic review of the literature, we examined the epidemiology, symptomatology, management, and outcomes of patients with hypoglossal schwannomas.

Methods: The electronic database Pubmed was searched for all reports of hypoglossal schwannomas with descriptions of symptoms, management, and outcome characteristics. Data was extracted from each study and compiled in a spreadsheet. Continuous variables were reported as means and medians. Categorical variables were reported as proportions. Additional analysis was not done due to inconsistent reporting of outcomes and small sample sizes.

Results: A total of 59 studies (94 total individual cases) were included. 64% of patients were female with mean age of 44.6 years. The majority were intracranial/extracranial (50%). The most common symptoms were tongue deviation or speech disturbance (38%) and headaches (33%). Hypoglossal nerve dysfunction was present in 80% of patients. Surgical excision was performed in 93%, with a 15% complication rate. Evidence of residual mass after surgery was noted in 29%. Permanent hypoglossal nerve deficits occurred in 67%. Recurrence of tumor burden was reported in 6 studies, with median time to recurrence of 16.5 months.

Conclusion: Current evidence suggests overall favorable outcomes with surgical resection of hypoglossal schwannomas, with a large percentage of patients experiencing mild and usually well-tolerated neurologic deficit. Limitations of this study include the use of retrospective data taken from case reports/series with highly selected patients, selective reporting, and absence of control groups.

Keywords: Cranial nerve 12; Hypoglossal schwannoma; Neck swelling; Peripheral schwannoma; Skull base mass; Twelfth nerve.

Publication types

  • Systematic Review

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cranial Nerve Neoplasms*
  • Female
  • Humans
  • Hypoglossal Nerve Diseases*
  • Male
  • Middle Aged
  • Neurilemmoma*