An MR Imaging Study of Communicating Hydrocephalus After Gamma Knife Radiosurgery for Vestibular Schwannoma

Abstract

Patients with vestibular schwannoma (VS) face a 3.7-23.7% risk developing hydrocephalus. Small-sized VS are associated with communicating or non-communicating hydrocephalus. Hydrocephalus in VS patients can persist or worsen post-tumor removal. Gamma knife radiosurgery is effective, especially in younger patients with functional hearing. Although the causal relationship between gamma knife radiosurgery and hydrocephalus isn't firmly established, this case reports a possible association between developing hydrocephalus and Vestibular schwannoma. Elevated CSF protein suggests communicating hydrocephalus due to tumor necrosis. The rarity of hydrocephalus post-gamma knife surgery likely relates to tumor variations rather than procedural nuances. Gamma Knife radiosurgery for vestibular schwannomas can lead to communicative hydrocephalus. MR imaging, including pre- and post-treatment scans, along with MR CSF cine-flow studies, highlights the link between gamma knife involvement and hydrocephalus development. Despite the rarity, this negative outcome underscores the need for careful consideration and investigation of risk factors associated with hydrocephalus post-radiosurgery. A middle aged man with vestibular schwannoma was investigated in this case. Patient was procedure through gamma knife radiosurgery for vestibular schwannoma. Patient was passed through MR scans before the radio surgical procedure and 9 months past surgical procedure. Nine months later, severe ventriculomegaly was observed, revealing central necrosis in the tumor. Lumbar puncture indicated abnormal CSF characteristics without evidence of infection. Despite a failed endoscopic third ventriculostomy, MR imaging cine-flow studies confirmed free CSF flow, emphasizing the complexity of managing hydrocephalus post-gamma knife radiosurgery for vestibular schwannomas. VS typically occurs in older individuals, this case's younger age and optimal tumor size for gamma knife treatment add complexity. Faster-growing and larger tumors are more prone to post-treatment necrosis and hydrocephalus, necessitating careful management. MR cine-flow aids in hydrocephalus differentiation.