vestibular schwannoma (acoustic neuroma)
Jump to navigation
Jump to search
Introduction
schwannoma or neurilemmoma of 8th nerve; acoustic neuroma is misnomer.
Etiology
- idiopathic sporadic unilateral 95%
- cancer susceptibility syndromes
Epidemiology
- 8% of all intracranial neoplasms
- lifetime prevalence of 1 in 500 persons
- increasing incidence due to enhanced detection
- most common in 6th or 7th decade in life
- 20 cases per 100,000 person years[8]
Pathology
- arise from myelinating Schwann cells of vestibular division of cranial nerve VIII[8]
- compressive growth with the internal auditory canal/meatus results in unilateral tinnitus & hearing loss
- compromise of cranial nerves VII & VIII, the brain stem & the cerebellum may occur
Clinical manifestations
- sensorineural hearing loss
- tinnitus &/or vertigo may be presenting symptoms
- hearing loss is usually unilateral (90%)[3][8]
- Weber test lateralizes to the unaffected ear
- symptoms are generally progressive rather than episodic
- symptoms are often unilateral
- vestibular symptoms (unsteadiness, balance issues)
- acoustic & vestibular symptoms are not reliable indicators of tumor growth[8]
- cranial nerves 5, 7, 9, 10, 11 may be affected with tumor progression[2]
- even large schwannomas generally do not affect facial-nerve, trigeminal motor, or lower cranial-nerve dysfunction[8]
- abnormal finger to nose test suggests compression of cerebellum
Diagnostic procedures
- audiometry 6 months after diagnostic MRI, then annually
- confirmatory biopsy rarely needed[8]
Radiology
- magnetic resonance imaging (MRI) of the posterior fossa & internal auditory canal with gadolinium contrast
- yield of MRI for vestibular schwannoma diagnosis < 3%[7]
- once diagnosed, serial imaging should be obtained at annually, regardless of symptoms[8]
Complications
- compression of cochlear nerve or labyrinthine artery
- impaired circulation of CSF
- inflammation mediated by schwannoma
- as the tumor enlarges, it compresses cranial nerves & the cerebellum[3]
Differential diagnosis
- facial-nerve schwannoma
- meningioma
- malignant peripheral-nerve sheath tumors
- metastases from primary tumors at other sites
- otosclerosis: associated with conductive hearing loss*
- cholesteoma: associated with conductive hearing loss*
* Weber test lateralizes to affected ear
Management
- referral to otorhinolaryngologist
- stereotactic radiosurgery - gamma-knife radiosurgery
- maximal neoplasm diameter < 3.0 cm in the cerebellopontine angle
- complications include: brain-stem edema, trigeminal neuralgia, hydrocephalus[8]
- upfront radiosurgery for small & medium size tumors results in greater tumor reduction at 4 years than treatment with tumor growth[10]
- microsurgical resection
- treatment of choice for large neoplasm associated with:
- symptomatic brain-stem compression, hydrocephalus, trigeminal neuralgia[8]
- general anesthesia, operating microscope, intraoperative neural monitoring
- treatment of choice for large neoplasm associated with:
- sensorineural hearing loss & vestibular dysfunction are not reversed with treatment[8]
- conservative management
- prioritizing preservation of neurologic function vs cure
- potential for overtreatment resulting in unnecessary complications & health care expenses
- untreated vestibular schwannoma in patients >= 70 years not associated with shorter lifespan[11]
- investigational drug treatment includes aspirin & monoclonal antibodies
- no strong evidence any treatment is superior to others
- some patients may require rehabilitation
More general terms
References
- ↑ UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 12-15, 2001
- ↑ 2.0 2.1 UpToDate 14.1 http://www.utdol.com
- ↑ 3.0 3.1 3.2 Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010
Geriatric Review Syllabus, 11th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022 - ↑ McDonald R Acoustic neuroma: what the evidence says about evaluation and treatment. J Fam Pract. 2011 Jun;60(6):E1-4. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21647465
- ↑ deprecated reference
- ↑ Acoustic Neuroma. NIH Consensus Statement Online 1991 Dec 11-13;9(4):1-24 http://consensus.nih.gov/cons/087/087_statement.htm
- ↑ 7.0 7.1 Dunn IF, Bi WL, Mukundan S et al. Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Imaging in the Diagnosis and Management of Patients With Vestibular Schwannomas. Neurosurgery. 2018 Feb 1;82(2)E32-34. PMID: https://www.ncbi.nlm.nih.gov/pubmed/29309686 https://academic.oup.com/neurosurgery/article/82/2/E32/4764045
Sweeney AD, Carlson ML, Shepard, NT. Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Otologic and Audiologic Screening for Patients With Vestibular Schwannomas. Congress of Neurological Surgeons. 2017. Neurosurgery. 2018 Feb 1;82(2):E29-E31. PMID: https://www.ncbi.nlm.nih.gov/pubmed/29309699 https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_2 - ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 Carlson ML, Link MJ Vestibular Schwannomas. N Engl J Med 2021; 384:1335-1348. April 8. PMID: https://www.ncbi.nlm.nih.gov/pubmed/33826821 https://www.nejm.org/doi/full/10.1056/NEJMra2020394
- ↑ Gupta VK, Thakker A, Gupta KK. Vestibular schwannoma: what we know and where we are heading. Head Neck Pathol. 2020;14(4):1058-1066 PMID: https://www.ncbi.nlm.nih.gov/pubmed/32232723 PMCID: PMC7669921 Free PMC article https://link.springer.com/article/10.1007/s12105-020-01155-x
- ↑ 10.0 10.1 Dhayalan D, Tveiten OV, Finnkirk M et al Upfront Radiosurgery vs a Wait-and-Scan Approach for Small- or Medium-Sized Vestibular Schwannoma. The V-REX Randomized Clinical Trial. JAMA. 2023;330(5):421-431. PMID: https://www.ncbi.nlm.nih.gov/pubmed/37526718 PMCID: PMC10394573 Free PMC article https://jamanetwork.com/journals/jama/fullarticle/2807745
- ↑ 11.0 11.1 Mistarz N, Reznitsky M, Hostmark K et al Life Expectancy After Diagnosis of a Vestibular Schwannoma in Patients 70 Years and Older. JAMA Otolaryngol Head Neck Surg. 2023 Oct 26. PMID: https://www.ncbi.nlm.nih.gov/pubmed/37883070 https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2811314
- ↑ Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis [NIDCD Health Information] http://www.nidcd.nih.gov/health/hearing/acoustic_neuroma.asp
Patient information
vestibular schwannoma (acoustic neuroma) patient information