BACKGROUND: Vestibular assessment in patients with acoustic tumor (so-called vestibular schwannoma, VS) via ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests are not often discussed in the neurosurgical literature. OBJECTIVES: This study conducted physiological and morphological assessments for VS patients before and after CyberKnife radiosurgery. METHODS: Twenty patients with unilateral VS underwent a battery of tests comprising facial nerve function test, audiometry, and caloric, oVEMP and cVEMP tests before and 2 years after CyberKnife treatment at a mean dosage of 18 Gy in 3 fractions. RESULTS: The abnormal percentages of caloric, oVEMP and cVEMP tests did not significantly differ before and after Cyberknife treatment, indicating that preservation of the superior and inferior vestibular nerves can be achieved after radiosurgery. Median tumor volumes, 1.49 cm3 before treatment versus 0.97 cm3 at 2 years after treatment, differed significantly. CONCLUSIONS: The use of oVEMP and cVEMP tests in VS patients before stereotactic radiosurgery may help to evaluate the tumor origin from the superior or inferior vestibular nerve. It takes a short time and costs less, and it would be practical to make this a routine examination in VS patients having stereotactic radiosurgery.
BACKGROUND: Vestibular assessment in patients with acoustic tumor (so-called vestibular schwannoma, VS) via ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests are not often discussed in the neurosurgical literature. OBJECTIVES: This study conducted physiological and morphological assessments for VS patients before and after CyberKnife radiosurgery. METHODS: Twenty patients with unilateral VS underwent a battery of tests comprising facial nerve function test, audiometry, and caloric, oVEMP and cVEMP tests before and 2 years after CyberKnife treatment at a mean dosage of 18 Gy in 3 fractions. RESULTS: The abnormal percentages of caloric, oVEMP and cVEMP tests did not significantly differ before and after Cyberknife treatment, indicating that preservation of the superior and inferior vestibular nerves can be achieved after radiosurgery. Median tumor volumes, 1.49 cm3 before treatment versus 0.97 cm3 at 2 years after treatment, differed significantly. CONCLUSIONS: The use of oVEMP and cVEMP tests in VS patients before stereotactic radiosurgery may help to evaluate the tumor origin from the superior or inferior vestibular nerve. It takes a short time and costs less, and it would be practical to make this a routine examination in VS patients having stereotactic radiosurgery.
Authors: Hossein Mahboubi; Ronald Sahyouni; Omid Moshtaghi; Kent Tadokoro; Yaser Ghavami; Kasra Ziai; Harrison W Lin; Hamid R Djalilian Journal: Otolaryngol Head Neck Surg Date: 2017-04-25 Impact factor: 3.497