Table 1_Brain microstructural alterations and cognitive impairment in obstructive sleep apnea: a diffusion kurtosis imaging study.docx

BackgroundThis study aimed to investigate brain microstructural alterations and their association with neurocognitive impairment in adults with moderate to severe obstructive sleep apnea (OSA) using diffusion kurtosis imaging (DKI), to better understand the neuropathological mechanisms contributing to cognitive decline in OSA.
Materials and methods40 OSA patients and 40 matched healthy controls (HCs) underwent cognitive assessments using the Montreal Cognitive Assessment (MoCA) and MRI scans including DKI and 3D T1-weighted imaging. DKI were processed to generate kurtosis parameter maps, including axial kurtosis (AK) and radial kurtosis (RK). Brain region values were extracted using SPM12. Group comparisons were conducted for cognitive scores and kurtosis values. Receiver operating characteristic (ROC) curves were used to assess the diagnostic performance of imaging biomarkers. Partial correlation analysis examined relationships between imaging metrics, cognitive scores, and sleep-related variables. Multiple comparisons were corrected using the false discovery rate (FDR) method.
ResultsThe OSA group showed increased AK in 9 brain regions and decreased RK in 28 regions. MoCA scores, particularly in visual space and executive function, abstraction, and delayed recall, were significantly lower in the OSA group. ROC analysis showed that RK in specific brain regions had strong diagnostic accuracy for OSA (AUC = 0.817). Lower oxygen saturation (LSpO2) was associated with altered kurtosis values in key regions related to cognition. Cognitive scores were positively correlated with RK values in regions such as the frontal cortex, cingulate cortex, and hippocampus.
ConclusionDKI effectively detects microstructural brain changes in OSA patients. These alterations are associated with cognitive decline, providing valuable insights into the potential mechanisms underlying neurocognitive impairments in OSA.

研究背景：本研究旨在采用扩散峰度成像（diffusion kurtosis imaging, DKI）技术，探究中重度阻塞性睡眠呼吸暂停（obstructive sleep apnea, OSA）成人患者的脑微观结构改变及其与神经认知功能损害的关联，以进一步阐明OSA患者认知衰退的神经病理机制。
材料与方法：40例OSA患者与40例匹配的健康对照（healthy controls, HCs）接受了蒙特利尔认知评估（Montreal Cognitive Assessment, MoCA）以及包含DKI和3D T1加权成像（3D T1-weighted imaging）的磁共振成像（MRI）扫描。对DKI数据进行处理以生成峰度参数图，包括轴向峰度（axial kurtosis, AK）与径向峰度（radial kurtosis, RK）。采用SPM12软件提取脑区的参数值。对认知评分与峰度值进行组间比较。采用受试者工作特征（Receiver operating characteristic, ROC）曲线评估影像学生物标志物的诊断效能。采用偏相关分析探究影像学指标、认知评分与睡眠相关变量之间的关联。采用错误发现率（false discovery rate, FDR）法对多重比较进行校正。
研究结果：OSA组在9个脑区的AK值升高，而在28个脑区的RK值降低。OSA组的MoCA评分显著低于健康对照组，尤其在视空间与执行功能、抽象能力以及延迟回忆维度表现明显。ROC分析显示，特定脑区的RK值对OSA具有较强的诊断效能（曲线下面积AUC=0.817）。最低血氧饱和度（lower oxygen saturation, LSpO2）与认知相关关键脑区的峰度值改变存在关联。额叶皮层、扣带回皮层以及海马等脑区的RK值与认知评分呈正相关。
研究结论：DKI可有效检测OSA患者的脑微观结构改变。此类改变与认知衰退密切相关，为阐明OSA患者神经认知功能损害的潜在病理机制提供了重要参考依据。