Functional recovery of cranial nerves VII and VIII after hypofractionated CyberKnife radiosurgery in a neuroblastoma patient with cerebellopontine angle metastasis—Case report

Abstract

Cerebellopontine angle (CPA) is a rare site for tumor metastasis, sually manifested with rapidly progressive neurological deficits nvolving cranial nerves V, VII, VIII and IX–XI, etc. [3]. Although surical intervention is beneficial to control the metastatic lesion and alt neurological deterioration, it poses significant risks in causng further neurological sequela. Therefore, early diagnosis as well s careful monitoring of the neurological functions is essential to anage the metastatic CPA lesions. There are four nerve bundles inside the internal auditory canals, amely, facial, cochlear, and superior and inferior vestibular nerves. onventionally, neurological examination and audiometry have een used to evaluate the facial and cochlear nerve functions, espectively. Recently, via air-conducted sound or bone-conducted ibration stimuli, vestibular-evoked myogenic potential (VEMP) as been recorded from tonically contracted cervical muscles, soalled “cervical” VEMP (cVEMP), and from extraocular muscles, so alled ocular VEMP (oVEMP). Previous investigations have demontrated that the cVEMP test assesses the ipsilateral sacculo-collic eflex via the inferior vestibular nerve, while the oVEMP test eval-