伽玛刀®立体定向放射外科 (SRS) 治疗前庭神经鞘瘤后出现脑积水的情况很少见，但可以控制。大多数系列报道约 1% 的患者出现 SRS 后交通性脑积水，这被认为与蛋白质物质释放到脑脊液中有关。虽然较大的肿瘤大小和较大的患者年龄与 SRS 后脑积水有关，但基线脑室解剖结构对脑积水风险的影响仍不清楚。一项单机构回顾性队列研究检查了接受伽玛刀® SRS 后出现症状性交通性脑积水的患者2011 年至 2021 年对单侧前庭神经鞘瘤进行了检查。既往有脑积水和脑脊液改道或既往手术切除的患者被排除。通过轴向增强 T1 加权磁共振成像测量基线肿瘤体积、第三脑室宽度和埃文斯指数 (EI)（侧脑室额角最大宽度/颅骨最大内径）。 总共 378 名患者符合纳入标准； 14 名患者（3.7%）出现症状性交通性脑积水，10 名患者（2.6%）接受分流术，4 名患者（1.1%）症状较轻。发生脑积水的患者的中位年龄为 69 岁（IQR，67-72），对于年龄小于 65 岁的患者，发生脑积水的风险为 1%。对于肿瘤体积<1 cm3，需要分流的风险为1.2%。在多变量分析中，基线 EI > 0.28 (P = .024) 和肿瘤体积 > 3 cm3 (P = .007) 导致出现症状性脑积水的几率分别高出 5.0 倍和 7.7 倍。 SRS 成像前的第四脑室变形与脑积水的发生率显着相关 (P < .001)。具有较高基线 EI、较大肿瘤体积和第四脑室变形的前庭神经鞘瘤患者发生 SRS 后脑积水的几率增加。这些患者应接受关于脑积水风险的咨询，并在 SRS 后仔细监测。版权所有 © 神经外科医生大会 2024。保留所有权利。

Hydrocephalus after Gamma Knife® stereotactic radiosurgery (SRS) for vestibular schwannomas is a rare but manageable occurrence. Most series report post-SRS communicating hydrocephalus in about 1% of patients, thought to be related to a release of proteinaceous substances into the cerebrospinal fluid. While larger tumor size and older patient age have been associated with post-SRS hydrocephalus, the influence of baseline ventricular anatomy on hydrocephalus risk remains poorly defined.A single-institution retrospective cohort study examining patients who developed symptomatic communicating hydrocephalus after undergoing Gamma Knife® SRS for unilateral vestibular schwannomas from 2011 to 2021 was performed. Patients with prior hydrocephalus and cerebrospinal fluid diversion or prior surgical resection were excluded. Baseline tumor volume, third ventricle width, and Evans Index (EI)-maximum width of the frontal horns of the lateral ventricles/maximum internal diameter of the skull-were measured on axial postcontrast T1-weighted magnetic resonance imaging.A total of 378 patients met the inclusion criteria; 14 patients (3.7%) developed symptomatic communicating hydrocephalus and 10 patients (2.6%) underwent shunt placement and 4 patients (1.1%) were observed with milder symptoms. The median age of patients who developed hydrocephalus was 69 years (IQR, 67-72) and for patients younger than age 65 years, the risk was 1%. For tumor volumes <1 cm3, the risk of requiring shunting was 1.2%. The odds of developing symptomatic hydrocephalus were 5.0 and 7.7 times higher in association with a baseline EI > 0.28 (P = .024) and tumor volume >3 cm3 (P = .007), respectively, in multivariate analysis. Fourth ventricle distortion on pre-SRS imaging was significantly associated with hydrocephalus incidence (P < .001).Patients with vestibular schwannoma with higher baseline EI, larger tumor volumes, and fourth ventricle deformation are at increased odds of developing post-SRS hydrocephalus. These patients should be counseled regarding risk of hydrocephalus and carefully monitored after SRS.Copyright © Congress of Neurological Surgeons 2024. All rights reserved.