Acharya Deepshikha, Butters Emilia, Caicedo Alexander, Su Li, O'Brien John, Bale Gemma
University of Cambridge, Electrical Division, Department of Engineering, Cambridge, United Kingdom.
University of Cambridge, School of Clinical Medicine, Department of Psychiatry, Cambridge, United Kingdom.
J Biomed Opt. 2025 Feb;30(Suppl 2):S23910. doi: 10.1117/1.JBO.30.S2.S23910. Epub 2025 Sep 3.
Broadband near-infrared spectroscopy (bNIRS) can simultaneously monitor several chromophores, including the oxidative state of cytochrome c-oxidase (oxCCO), an oxygen metabolism biomarker, the activity of which is altered in Alzheimer's disease. Being a portable and noninvasive neuromonitoring technique, bNIRS could provide accessibility to brain-specific biomarkers and aid in the dementia diagnostic pathway.
We use bNIRS-recorded functional hemodynamic and oxCCO changes to assess their relevance in Alzheimer's disease diagnosis.
Using a visual stimulus paradigm, we recorded functional changes in oxy-, deoxy-hemoglobin and oxCCO in three similarly aged cohorts: healthy controls ( ), individuals with mild cognitive impairment ( ), and individuals with early Alzheimer's dementia ( ). We then selected features from these functional responses to find the best correlation with clinical cognitive markers (cognitive and behavioral test scores and clinical diagnoses) using canonical correlation analysis (CCA).
We found individual variations in peak amplitude and time-to-peak for all the stimulus-evoked bNIRS signals across the three cohorts. CCA showed a strong correlation between bNIRS features and the clinical cognitive markers ( ). However, repeating the same analysis by excluding the bNIRS oxCCO features leads to a significantly lower correlation ( ) with the clinical markers.
oxCCO could be a crucial biomarker, partly explaining cognitive differences with dementia. bNIRS uniquely provides a portable and noninvasive technique to monitor several chromophores simultaneously, including oxCCO, with potential future applications in diagnosing and tracking dementia progression.
宽带近红外光谱（bNIRS）可同时监测多种发色团，包括细胞色素c氧化酶（oxCCO）的氧化状态，oxCCO是一种氧代谢生物标志物，其活性在阿尔茨海默病中会发生改变。作为一种便携式无创神经监测技术，bNIRS能够获取脑特异性生物标志物，并有助于痴呆症的诊断途径。
我们使用bNIRS记录的功能性血流动力学和oxCCO变化来评估它们在阿尔茨海默病诊断中的相关性。
采用视觉刺激范式，我们记录了三个年龄相仿队列中氧合血红蛋白、脱氧血红蛋白和oxCCO的功能变化：健康对照组、轻度认知障碍个体和早期阿尔茨海默病痴呆个体。然后，我们从这些功能反应中选择特征，使用典型相关分析（CCA）来找到与临床认知标志物（认知和行为测试分数以及临床诊断）的最佳相关性。
我们发现三个队列中所有刺激诱发的bNIRS信号的峰值幅度和峰值时间存在个体差异。CCA显示bNIRS特征与临床认知标志物之间存在强相关性。然而，通过排除bNIRS oxCCO特征重复相同分析，与临床标志物的相关性显著降低。
oxCCO可能是一种关键的生物标志物，部分解释了与痴呆症相关的认知差异。bNIRS独特地提供了一种便携式无创技术，可同时监测多种发色团，包括oxCCO，在未来诊断和跟踪痴呆症进展方面具有潜在应用价值。
