![]() ![]() 14 Surgical outcome, in general, remained poor in the late 1800s, with a surgical mortality rate of 80% and high postoperative morbidity. A few years later, Sir Charles Ballance in England was the first to successfully remove a VS via a suboccipital plate and blunt dissection of a CPA mass. 12Ĭharles McBurney performed the first suboccipital plate removal in 1891, 13 though the patient died soon after. Sensorineural hearing loss is confirmed by audiometry and brain stem–evoked response audiometry, with findings that are abnormal in >90%–95% of patients with VS. True vertigo, sudden hearing loss, facial pain, numbness, and weakness are uncommon due to slow tumor growth. Patients more often present with chronic asymmetric sensorineural hearing loss than tinnitus or unsteadiness. Symptomatology is often related to cranial neuropathies. ![]() VS presents at a median age of 50 years and is unilateral in >90% of patients, with an equal incidence on the left and right. Immunohistochemical staining is typically positive for S-100 protein. Perineural elements of Schwann cells, with areas of dense (Antoni A) and sparse (Antoni B) cellularity, are found histopathologically. 11 This gene is located on chromosome 22 and produces schwannomin (merlin), a tumor-suppressor cell membrane–related protein. Inactivation of the neurofibromin 2 gene has been implicated in sporadic and neurofibromatosis type 2 VS. VS, often referred to as “acoustic neuroma,” most commonly originates from the vestibular division of the vestibulocochlear nerve sheath, often at the transition from central to peripheral myelin near the vestibular ganglion at the IAC fundus. Knowledge of these advances enhances the radiologist's ability to participate in a multidisciplinary team by providing key information relevant to the treatment planning and outcome. This article will review the treatment objectives, surgical approaches, and expected posttreatment findings and complications of VS management. Observation is a reasonable option for smaller tumors, older patients, and those with major comorbidities. Stereotactic radiosurgery (SRS) is an acceptable option, with similar rates of tumor control and a low risk for permanent facial nerve palsy. Each approach offers different surgical exposures, benefits, and disadvantages. ![]() Patients with neurofibromatosis type 2, which is characterized by bilateral VSs, other schwannomas, meningiomas, ependymomas, and ocular abnormalities, are managed differently than those with sporadic unilateral VSs 10 and will not be further discussed due to the scope of this topic.Īdvances in surgical management of VS during the past century have defined lateral skull base approaches that are now applied in the management of other PF and skull base pathologies. 8, 9 Depending on many factors, including patient age, tumor size and growth, and symptomatology, patients can choose surgery, radiation, or conservative management. 6, 7 Studies have revealed suboptimal postsurgical facial nerve function in gross total resection of large VSs. The goals of VS management have shifted from total resection to functional preservation, particularly when the entire tumor cannot be safely resected with respect to cranial nerve preservation. 3 ⇓– 5 Contrast-enhanced CT of the temporal bones can serve as an alternative if the patient cannot undergo MR imaging. 2 MR imaging is the preferred technique and can provide exquisite tumor characterization, surgical planning, and posttherapeutic evaluation. Imaging can often differentiate VS from other entities such as facial nerve schwannoma, meningioma, epidermoid cyst, arachnoid cyst, aneurysm, and metastasis. Imaging plays a central role in the screening and initial and follow-up assessment of VSs. Symptoms are typically related to compression of adjacent cranial nerves (CNs), brain stem, or posterior fossa (PF) structures. 1 VSs may remain within the internal auditory canal (IAC) or extend into the CPA. Vestibular schwannomas (VSs) are benign neoplasms of the nerve sheath and account for 6%–8% of all intracranial tumors and 80% of cerebellopontine angle (CPA) tumors. ABBREVIATIONS: AAO-HNS American Academy of Otolaryngology-Head and Neck Surgery CN cranial nerve CPA cerebellopontine angle 3D SS-GRE volumetrically acquired steady-state gradient-echo IAC internal auditory canal MF middle fossa craniotomy PF posterior fossa RS retrosigmoid craniotomy SRS stereotactic radiosurgery TL translabyrinthine craniotomy VS vestibular schwannoma ![]()
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