Cranial nerve preservation in contemporary vestibular schwannoma (acoustic neuroma) treatment

Abstract

Vestibular schwannomas (acoustic neuromas) have long been considered one of the most difficult tumors to remove without causing neurologic dysfunction. In recent years, with marked improvements in neurophysiologic monitoring, microsurgical techniques, and neuroimaging, the focus of treatment has shifted from prolongation of life to preservation of cranial nerve function. Contemporary treatment of vestibular schwannoma includes serial evaluation with magnetic resonance imaging, conventional microsurgical resection, and stereotactic radiosurgery. Microsurgical removal may be subdivided by approach: retrosigmoid, translabyrinthine, or middle fossa depending on the patient’s preoperative neurologic status and the experience of the surgeon. Furthermore, radiosurgery may involve gamma knife radiation, linear accelerator, or heavy particle radiation. Despite great advances in the treatment of these complex tumors, there is still debate as to what constitutes optimal management. This is particularly true when one considers cranial nerve preservation. In this review, we analyze several recent articles that deal with strategies for preserving cranial nerve function before, during, and after treatment. We present a variety of perspectives, and in doing so, we hope to shed light on some of the ongoing controversies surrounding the contemporary treatment of vestibular schwannomas.