Murambi Ronald T, Chour Henora, Kasprowicz Magdalena, Vonhoff Craig R, Czosnyka Marek, Czosnyka Zofia, Jaeger Matthias
Department of Neurosurgery, Wollongong Hospital, Loftus Street, Wollongong, NSW, 2500, Australia.
Graduate School of Medicine, University of Wollongong, Wollongong, NSW, Australia.
Fluids Barriers CNS. 2025 Jun 18;22(1):61. doi: 10.1186/s12987-025-00670-9.
Enlarged brain ventricles, compressed parasagittal cerebrospinal fluid spaces, steep callosal angle, dilated sylvian fissures and focal cortical sulcal dilatation are typical imaging features of idiopathic normal pressure hydrocephalus (iNPH). The pathophysiological mechanisms behind these morphological changes are poorly understood, but the hydrodynamic concepts of communicating hydrocephalus suggest that increased heartbeat related intracranial pulsations are involved in ventricular enlargement. In this cross-sectional study we analysed the association between the radiological findings of iNPH and the physiological intracranial pressure (ICP) waveform components.
117 patients with suspected iNPH underwent computerised overnight ICP monitoring with calculation of heartbeat related ICP pulse wave amplitude (calculated in the frequency domain, AMP, and time domain, MWA), amplitude of respiration induced ICP waves (RESP), power of slow vasogenic waves (SLOW), and index of cerebrospinal compensatory reserve (RAP). Radiological morphological data was recorded from computed tomography using Evans Index (EI), frontal occipital horn ratio (FOHR), and disproportionately enlarged subarachnoid space hydrocephalus (DESH) score.
The strongest correlation was observed between SLOW and DESH (r = 0.44, p < 0.012). SLOW also correlated with ventricular size as measured with EI (r = 0.23, p = 0.045) and FOHR (r = 0.26, p = 0.037). ICP and RESP also correlated with DESH (r = 0.25, p = 0.037 and r = 0.25, p = 0.038, respectively). AMP and MWA were not correlated with the radiological data.
Mainly SLOW showed correlations with the morphological imaging features of iNPH. SLOW is influenced by vasomotion and intracranial compliance. This study suggests that the magnitude of ICP slow wave activity, but not ICP pulse component is related to the size of brain ventricles and DESH in iNPH.
脑室内径增大、矢状窦旁脑脊液间隙受压、胼胝体角变陡、大脑外侧裂增宽以及局灶性皮质沟增宽是特发性正常压力脑积水（iNPH）的典型影像学特征。这些形态学改变背后的病理生理机制尚不清楚，但交通性脑积水的流体动力学概念表明，与心跳相关的颅内搏动增加与脑室扩大有关。在这项横断面研究中，我们分析了iNPH的影像学表现与生理性颅内压（ICP）波形成分之间的关联。
117例疑似iNPH患者接受了夜间计算机化ICP监测，计算与心跳相关的ICP脉搏波振幅（在频域计算为AMP，在时域计算为MWA）、呼吸诱导的ICP波振幅（RESP）、缓慢血管源性波的功率（SLOW）以及脑脊液代偿储备指数（RAP）。使用埃文斯指数（EI）、额枕角比值（FOHR）和蛛网膜下腔脑积水不成比例扩大（DESH）评分从计算机断层扫描记录放射形态学数据。
观察到SLOW与DESH之间的相关性最强（r = 0.44，p < 0.012）。SLOW也与用EI（r = 0.23，p = 0.045）和FOHR（r = 0.26，p = 0.037）测量的脑室大小相关。ICP和RESP也与DESH相关（分别为r = 0.25，p = 0.037和r = 0.25，p = 0.038）。AMP和MWA与放射学数据无关。
主要是SLOW与iNPH的形态学影像学特征相关。SLOW受血管运动和颅内顺应性影响。本研究表明，iNPH中ICP慢波活动的幅度而非ICP脉冲成分与脑室大小和DESH有关。
