Perry Avital, Graffeo Christopher S, Fattahi Nikoo, ElSheikh Mona M, Cray Nealey, Arani Arvin, Ehman Richard L, Glaser Kevin J, Manduca Armando, Meyer Fredric B, Huston John
Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
World Neurosurg. 2017 Mar;99:695-700.e1. doi: 10.1016/j.wneu.2016.12.121. Epub 2017 Jan 5.
Idiopathic normal pressure hydrocephalus (iNPH) is a ventriculomegaly syndrome characterized by dementia, urinary incontinence, and gait disturbance, which is potentially reversible after ventriculoperitoneal shunting (VPS). Magnetic resonance elastography (MRE) is an evolving imaging technology that noninvasively measures tissue viscoelasticity. We studied iNPH patients using MRE prior to shunting, compared them with normal controls, and analyzed associations between MRE findings and clinical features, as a pilot assessment of MRE in iNPH.
Stiffness values were measured on preoperative MRE in 10 iNPH patients scheduled for VPS and compared with those in 20 age- and sex-matched controls. Stiffness results were correlated with clinical iNPH symptoms.
MRE demonstrated significantly increased stiffness in iNPH in cerebrum (P = 0.04), occipital (P = 0.002), and parietal (P = 0.01) regions of interest (ROIs) and significantly decreased stiffness in periventricular ROIs (P < 0.0001). Stiffness was not significantly different in frontal (P = 0.1) and deep gray ROIs (P = 0.4). Univariate analysis showed associations between preoperative iNPH symptoms and abnormally increased stiffness, including urinary incontinence with cerebrum (P = 0.005), frontal (P = 0.04), and cerebellum (P = 0.03) ROIs, and Parkinsonism with occipital ROI (P = 0.04). Postoperative improvement was associated with increased deep gray stiffness (P = 0.01); failure was associated with increased temporal (P = 0.0002) stiffness.
Based on the preliminary results of this small, limited analysis, brain stiffness may be altered in iNPH, and these alterations in parenchymal viscoelastic properties may be correlated with clinical symptoms. Increased temporal stiffness may predict surgical failure and potentially suggest an alternative dementing pathology underlying the iNPH-like symptoms. These findings highlight the potential future utility of MRE in iNPH management.
特发性正常压力脑积水(iNPH)是一种脑室扩大综合征,其特征为痴呆、尿失禁和步态障碍,脑室腹腔分流术(VPS)后可能可逆。磁共振弹性成像(MRE)是一种不断发展的成像技术,可无创测量组织粘弹性。我们在分流术前使用MRE对iNPH患者进行研究,将他们与正常对照进行比较,并分析MRE结果与临床特征之间的关联,作为对iNPH中MRE的初步评估。
对10例计划接受VPS的iNPH患者术前MRE测量硬度值,并与20例年龄和性别匹配的对照进行比较。硬度结果与iNPH临床症状相关。
MRE显示iNPH患者大脑(P = 0.04)、枕叶(P = 0.002)和顶叶(P = 0.01)感兴趣区(ROI)的硬度显著增加,脑室周围ROI的硬度显著降低(P < 0.0001)。额叶(P = 0.1)和深部灰质ROI(P = 0.4)的硬度无显著差异。单因素分析显示术前iNPH症状与异常增加的硬度之间存在关联,包括尿失禁与大脑(P = 0.005)、额叶(P = 0.04)和小脑(P = 0.03)ROI相关,帕金森综合征与枕叶ROI相关(P = 0.04)。术后改善与深部灰质硬度增加相关(P = 0.01);手术失败与颞叶硬度增加相关(P = 0.0002)。
基于这项小型、有限分析的初步结果,iNPH患者的脑硬度可能发生改变,这些实质粘弹性特性的改变可能与临床症状相关。颞叶硬度增加可能预测手术失败,并可能提示iNPH样症状背后存在另一种痴呆病理。这些发现凸显了MRE在iNPH管理中未来的潜在应用价值。