From the Departments of Radiology (S.M.S., M.B.).
From the Departments of Radiology (S.M.S., M.B.)
AJNR Am J Neuroradiol. 2022 Feb;43(2):230-237. doi: 10.3174/ajnr.A7385. Epub 2022 Jan 6.
Normal pressure hydrocephalus is characterized by systolic peaks of raised intracranial pressure, possibly due to a reduced compliance of the spinal CSF spaces. This concept of a reduced spinal CSF buffer function may be reflected by a low cervical CSF outflow from the cranium. The aim of this study was to investigate craniospinal CSF flow rates by phase-contrast MR imaging in patients with normal pressure hydrocephalus.
A total of 42 participants were included in this prospective study, consisting of 3 study groups: 1) 10 patients with normal pressure hydrocephalus (mean age, 74 [SD, 6] years, with proved normal pressure hydrocephalus according to current scientific criteria); 2) eighteen age-matched healthy controls (mean age, 71 [SD, 5] years); and 3) fourteen young healthy controls (mean age, 21 [SD, 2] years, for investigation of age-related effects). Axial phase-contrast MR imaging was performed, and the maximal systolic CSF and total arterial blood flow rates were measured at the level of the upper second cervical vertebra and compared among all study groups (2-sample unpaired test).
The maximal systolic CSF flow rate was significantly decreased in patients with normal pressure hydrocephalus compared with age-matched and young healthy controls (53 [SD, 40] mL/m; 329 [SD, 175] mL/m; 472 [SD, 194] mL/m; each < .01), whereas there were no significant differences with regard to maximal systolic arterial blood flow (1160 [SD, 404] mL/m; 1470 [SD, 381] mL/m; 1400 [SD, 254] mL/m; each > .05).
The reduced maximal systolic craniospinal CSF flow rate in patients with normal pressure hydrocephalus may be reflective of a reduced compliance of the spinal CSF spaces and an ineffective spinal CSF buffer function. Systolic craniospinal CSF flow rates are an easily obtainable MR imaging-based measure that may support the diagnosis of normal pressure hydrocephalus.
正常压力脑积水的特征是颅内压升高的收缩期峰值，可能是由于脊髓脑脊液空间的顺应性降低所致。脊髓脑脊液缓冲功能降低的概念可能反映为脑脊液从颅腔流出的颈椎脑脊液流出量较低。本研究旨在通过相位对比磁共振成像（MR 成像）研究正常压力脑积水患者的颅脊髓脑脊液流量。
本前瞻性研究共纳入 42 名参与者，包括 3 个研究组：1）10 例正常压力脑积水患者（平均年龄 74 [标准差 6] 岁，根据当前科学标准证实为正常压力脑积水）；2）18 名年龄匹配的健康对照者（平均年龄 71 [标准差 5] 岁）；3）14 名年轻健康对照者（平均年龄 21 [标准差 2] 岁，用于研究年龄相关影响）。行轴向相位对比 MR 成像，并在第二颈椎上水平测量最大收缩期脑脊液和总动脉血流速度，并在所有研究组之间进行比较（2 样本非配对 t 检验）。
与年龄匹配的健康对照组和年轻健康对照组相比，正常压力脑积水患者的最大收缩期脑脊液流量明显降低（53 [标准差 40] mL/m；329 [标准差 175] mL/m；472 [标准差 194] mL/m；均<.01），而最大收缩期动脉血流无显著差异（1160 [标准差 404] mL/m；1470 [标准差 381] mL/m；1400 [标准差 254] mL/m；均>.05）。
正常压力脑积水患者最大收缩期颅脊髓脑脊液流量降低可能反映脊髓脑脊液空间顺应性降低和脊髓脑脊液缓冲功能无效。收缩期颅脊髓脑脊液流量是一种易于获得的基于磁共振成像的测量方法，可能有助于正常压力脑积水的诊断。
