Frič Radek, Lindstrøm Erika Kristina, Ringstad Geir Andre, Mardal Kent-André, Eide Per Kristian
Department of Neurosurgery, Oslo University Hospital - Rikshospitalet, PO Box 4950, Nydalen, 0424, Oslo, Norway.
Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.
Acta Neurochir (Wien). 2016 Dec;158(12):2295-2304. doi: 10.1007/s00701-016-2979-x. Epub 2016 Oct 14.
In symptomatic Chiari malformation type 1 (CMI), impaired intracranial compliance (ICC) is associated with an increased cranio-spinal pulsatile pressure gradient. Phase-contrast magnetic resonance imaging (MRI) represents a non-invasive modality for the assessment of the pulse pressure gradient at the cranio-cervical junction (CCJ). We wished to explore how the MRI-derived pulse pressure gradient (MRI-dP) compares with invasively measured pulsatile intracranial pressure (ICP) in CMI, and with healthy controls.
From phase-contrast MRI of CMI patients and healthy controls, we computed cerebrospinal fluid (CSF) flow velocities and MRI-dP at the CCJ. We assessed bidirectional flow and compared the flow between the anterior and the posterior subarachnoid space at the CCJ. We computed total intracranial volume (ICV), ventricular CSF volume (VV), and posterior cranial fossa volume (PCFV). We analyzed the static and pulsatile ICP scores from overnight monitoring in CMI patients.
Five CMI patients and four healthy subjects were included. The CMI group had a significantly larger extent of tonsillar ectopia, smaller PCFV, and a smaller area of CSF in the FM. The pulsatile ICP (mean ICP wave amplitude, MWA) was abnormally increased in 4/5 CMI patients and correlated positively with MRI-dP. However, the MRI-dP as well as the CSF flow velocities did not differ significantly between CMI and healthy subjects. Moreover, bidirectional flow was observed in both CMI as well as healthy subjects, with no significant difference.
In symptomatic CMI patients, we found a significant association between the pulse pressure gradient at the CCJ derived from phase-contrast MRI and the pulsatile ICP (MWA) measured invasively. However, the MRI-dP was close to identical in CMI patients and healthy subjects. Moreover, the CSF flow velocities at the CCJ and the occurrence of bidirectional flow were not different in CMI patients and healthy individuals. Further studies are required to determine the diagnostic role of phase-contrast MRI in CMI patients.
在症状性1型Chiari畸形（CMI）中，颅内顺应性（ICC）受损与颅-脊髓搏动性压力梯度增加有关。相位对比磁共振成像（MRI）是一种用于评估颅颈交界处（CCJ）脉压梯度的非侵入性方法。我们希望探讨CMI患者中MRI衍生的脉压梯度（MRI-dP）与有创测量的搏动性颅内压（ICP）以及健康对照相比情况如何。
通过CMI患者和健康对照的相位对比MRI，我们计算了CCJ处的脑脊液（CSF）流速和MRI-dP。我们评估了双向流动，并比较了CCJ处蛛网膜下腔前后间隙之间的流动。我们计算了总颅内体积（ICV）、脑室CSF体积（VV）和后颅窝体积（PCFV）。我们分析了CMI患者过夜监测的静态和搏动性ICP评分。
纳入了5例CMI患者和4名健康受试者。CMI组扁桃体异位程度明显更大，PCFV更小，FM中CSF面积更小。4/5的CMI患者搏动性ICP（平均ICP波幅，MWA）异常升高，且与MRI-dP呈正相关。然而，CMI患者和健康受试者之间的MRI-dP以及CSF流速没有显著差异。此外，在CMI患者和健康受试者中均观察到双向流动，无显著差异。
在有症状的CMI患者中，我们发现相位对比MRI得出的CCJ处脉压梯度与有创测量的搏动性ICP（MWA）之间存在显著关联。然而，CMI患者和健康受试者的MRI-dP几乎相同。此外，CMI患者和健康个体在CCJ处的CSF流速以及双向流动的发生情况并无差异。需要进一步研究以确定相位对比MRI在CMI患者中的诊断作用。
