Neurocritical Care Unit, Department of Neurosurgery, Institute of Intensive Care Medicine, University Hospital, University of Zurich, 8091, Zurich, Switzerland.
Department of Neurology, University Hospital Zurich, University of Zurich, 8091, Zurich, Switzerland.
Sci Rep. 2024 May 17;14(1):11287. doi: 10.1038/s41598-024-61819-4.
Spectrum power analysis in the low frequency oscillations (LFO) region of functional near infrared spectroscopy (fNIRS) is a promising method to deliver information about brain activation and therefore might be used for prognostication in patients with disorders of consciousness in the neurocritical care unit alongside with established methods. In this study, we measure the cortical hemodynamic response measured by fNIRS in the LFO region following auditory and somatosensory stimulation in healthy subjects. The significant hemodynamic reaction in the contralateral hemisphere correlation with the physiologic electric response suggests neurovascular coupling. In addition, we investigate power spectrum changes in steady state measurements of cerebral death patients and healthy subjects in the LFO region, the frequency of the heartbeat and respiration. The spectral power within the LFO region was lower in the patients with cerebral death compared to the healthy subjects, whereas there were no differences in spectral power for physiological activities such as heartbeat and respiration rate. This finding indicates the cerebral origin of our low frequency measurements. Therefore, LFO measurements are a potential method to detect brain activation in patients with disorders of consciousness and cerebral death. However, further studies in patients are needed to investigate its potential clinical use.
功能近红外光谱学（fNIRS）低频振荡（LFO）区域的光谱功率分析是一种很有前途的方法，可以提供有关大脑激活的信息，因此可能与已建立的方法一起用于神经危重症监护病房中意识障碍患者的预后。在这项研究中，我们测量了健康受试者在听觉和躯体感觉刺激后 fNIRS 在 LFO 区域测量的皮质血流动力学反应。对侧半球的显著血流动力学反应与生理电反应相关，表明存在神经血管耦合。此外，我们还研究了在 LFO 区域中脑死亡患者和健康受试者的稳态测量中的功率谱变化，包括心跳和呼吸频率。与健康受试者相比，脑死亡患者的 LFO 区域内的光谱功率较低，而心跳和呼吸率等生理活动的光谱功率没有差异。这一发现表明我们低频测量的大脑起源。因此，LFO 测量是一种检测意识障碍和脑死亡患者大脑激活的潜在方法。然而，还需要在患者中进行进一步的研究，以探讨其潜在的临床应用。
