Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Department of Anesthesia and Intensive Care Medicine, Karolinska University Hospital, Stockholm, Sweden.
J Neuroimaging. 2024 Sep-Oct;34(5):572-580. doi: 10.1111/jon.13224. Epub 2024 Jul 21.
The optic nerve sheath diameter (ONSD) is a commonly used estimate of intracranial pressure (ICP). The rationale behind this is that pressure changes in the cerebrospinal fluid affect the optic nerve subarachnoid space (ONSAS) thickness. Still, possible effects on other compartments of the optic nerve sheath (ONS) have not been studied. This is the first study ever to analyze all measurable compartments of the ONS for associations with elevated ICP.
We measured changes in ICP and changes in ONS compartments in 75 patients treated with invasive ICP monitoring at the Karolinska University Hospital. Associations between changes in ICP and changes in ONS compartments were estimated with generalized estimating equations. The potential to identify elevated ICP was assessed with the area under the receiver operating characteristic curve (AUROC) for ONS compartments associated with ICP changes.
Both ONSAS and perioptic dura mater thickness were significantly associated with changes in ICP in multivariable modeling. ONSAS was the only compartment that independently predicted changes in ICP, with an AUROC of 0.69 for predicting ICP increase. Still, both the perioptic dura mater thickness and the optic nerve diameter added value in predicting ICP changes in multivariable modeling.
The results from this study challenge the current understanding of the mechanism behind the association between ICP and ONSD. Contrary to the common opinion that ONSAS is the only affected compartment, this study shows a more complex picture. It suggests that all ONS compartments may add value in predicting changes in ICP.
视神经鞘直径（ONSD）是一种常用于估计颅内压（ICP）的方法。其理论基础是脑脊液压力变化会影响视神经蛛网膜下腔（ONSAS）的厚度。然而，尚未研究这种方法对视神经鞘（ONS）其他腔室的可能影响。这是第一项分析 ONS 所有可测量腔室与升高的 ICP 之间关联的研究。
我们测量了在卡罗林斯卡大学医院接受有创 ICP 监测治疗的 75 名患者的 ICP 变化和 ONS 腔室变化。使用广义估计方程估计 ICP 变化与 ONS 腔室变化之间的关联。通过与 ICP 变化相关的 ONS 腔室的接受者操作特征曲线（AUROC）评估识别升高的 ICP 的潜力。
在多变量模型中，ONSAS 和眶周硬脑膜厚度均与 ICP 变化显著相关。ONSAS 是唯一独立预测 ICP 变化的腔室，预测 ICP 增加的 AUROC 为 0.69。然而，眶周硬脑膜厚度和视神经直径在多变量模型中预测 ICP 变化方面均具有附加价值。
这项研究的结果挑战了目前对 ICP 和 ONSD 之间关联机制的理解。与普遍认为 ONSAS 是唯一受影响腔室的观点相反，本研究显示出更为复杂的情况。这表明所有 ONS 腔室在预测 ICP 变化方面都可能具有价值。
