Gholampour Seifollah, Yamini Bakhtiar, Droessler Julie, Frim David
Department of Neurological Surgery, University of Chicago, Chicago, IL, United States.
Front Bioeng Biotechnol. 2022 Aug 1;10:900644. doi: 10.3389/fbioe.2022.900644. eCollection 2022.
The clinical application of intracranial compliance (ICC), ∆V/∆P, as one of the most critical indexes for hydrocephalus evaluation was demonstrated previously. We suggest a new definition for the concept of ICC (long-term ICC) where there is a longer amount of elapsed time (up to 18 months after shunting) between the measurement of two values (V and V or P and P). The head images of 15 adult patients with communicating hydrocephalus were provided with nine sets of imaging in nine stages: prior to shunting, and 1, 2, 3, 6, 9, 12, 15, and 18 months after shunting. In addition to measuring CSF volume (CSFV) in each stage, intracranial pressure (ICP) was also calculated using fluid-structure interaction simulation for the noninvasive calculation of ICC. Despite small increases in the brain volume (16.9%), there were considerable decreases in the ICP (70.4%) and CSFV (80.0%) of hydrocephalus patients after 18 months of shunting. The changes in CSFV, brain volume, and ICP values reached a stable condition 12, 15, and 6 months after shunting, respectively. The results showed that the brain tissue needs approximately two months to adapt itself to the fast and significant ICP reduction due to shunting. This may be related to the effect of the "viscous" component of brain tissue. The ICC trend between pre-shunting and the first month of shunting was descending for all patients with a "mean value" of 14.75 ± 0.6 ml/cm HO. ICC changes in the other stages were oscillatory (nonuniform). Our noninvasive long-term ICC calculations showed a nonmonotonic trend in the CSFV-ICP graph, the lack of a relationship between ICC and ICP, and an oscillatory increase in ICC values during shunt treatment. The oscillatory changes in long-term ICC may reflect the clinical variations in hydrocephalus patients after shunting.
颅内顺应性（ICC），即∆V/∆P，作为脑积水评估的最关键指标之一，其临床应用先前已有报道。我们提出了ICC概念的新定义（长期ICC），即在测量两个值（V和V或P和P）之间有更长的时间间隔（分流后长达18个月）。为15例交通性脑积水成年患者的头部影像提供了九个阶段的九组成像：分流前，以及分流后1、2、3、6、9、12、15和18个月。除了在每个阶段测量脑脊液体积（CSFV）外，还使用流固相互作用模拟计算颅内压（ICP），以无创方式计算ICC。尽管脑容量有小幅增加（16.9%），但分流18个月后，脑积水患者的ICP（70.4%）和CSFV（80.0%）有显著下降。CSFV、脑容量和ICP值的变化分别在分流后12、15和6个月达到稳定状态。结果表明，脑组织需要大约两个月的时间来适应因分流导致的快速且显著的ICP降低。这可能与脑组织“粘性”成分的作用有关。所有患者在分流前至分流后第一个月期间，ICC趋势呈下降，“平均值”为14.7±0.6 ml/cm H₂O。其他阶段的ICC变化呈振荡性（不均匀）。我们的无创长期ICC计算结果显示，在CSFV-ICP图中呈非单调趋势，ICC与ICP之间缺乏相关性，且在分流治疗期间ICC值呈振荡性增加。长期ICC的振荡性变化可能反映了脑积水患者分流后的临床变化。
