Near-infrared spectroscopy (NIRS) as a useful tool to evaluate the treatment efficacy of positive airways pressure therapy in patients with obstructive sleep apnea syndrome (OSAS): A pilot study

Abstract

In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to an impaired cerebral vascular autoregulation that is associated with an increased cardiovascular risk, including stroke. Continuous positive airways pressure (CPAP) therapy at night is the most e®ective treatment for OSA and has been shown to reduce the cardiovascular risk in OSA patients. However, there is no suitable bedside monitoring method evaluating the recovery of cerebral hemodynamics during CPAP therapy. Near-infrared spectroscopy (NIRS) is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep due to its properties of local measurement, totally safe application and good tolerance to motion. In this pilot study, we monitored cerebral hemodynamics during standard CPAP therapy at night in three patients with severe OSA using NIRS. We found periodic oscillations in HbO 2 , HHb, tissue oxygenation index (TOI) and blood volume (BV) associated with periodic apnea events without CPAP in all OSA patients. These oscillations were eliminated under the optimal CPAP pressures in all patients. These results suggested that the recovery of cerebral hemodynamics impaired by apnea events can be evaluated by bedside NIRS measurements in real time during all night CPAP therapy. NIRS is a useful bedside monitoring tool to evaluate the treatment e±cacy of CPAP therapy in patients with OSA.

A pilot study to compare the cerebral hemodynamics between patients with obstructive sleep apnea syndrome (OSA) and periodic limb movement syndrome (PLMS) during nocturnal sleep with near-infrared spectroscopy (NIRS)

“…In this pilot study, we found that cerebral hemodynamics showed different changing patterns induced by periodic The oscillations in cerebral HbO2, HHb and BV induced by OSA events in this study have been repeated confirmed by previous studies [13][14][15][16][17][18] . All of these studies, reported on a decrease in HbO2 while an increase in HHb during A/H events, and a reverse pattern immediately after the end of the events.…”

“…It is a powerful tool to study cerebral hemodynamics during all night sleep 12 . Several studies with NIRS repeatedly reported an impairment of cerebral oxygenation in the patients with sleep apnea [13][14][15][16][17][18] . However, no study has compared cerebral hemodynamics in patients with OSA and PLMS so far.…”

Predominant endothelial vasomotor activity during human sleep: a near‐infrared spectroscopy study

“…The NIRS data obtained from brain and muscle were compared in both the time domain and the frequency domain. Several data‐preprocessing steps were performed before the comparisons (Zhang et al ., ).…”

Extracting heartrate from optical signal of functional near-infrared spectroscopy based on mathematical morphology

“…Along with the development of methods for processing fNIRS data, [1][2][3] fNIRS has been wildly used in cognitive neuroscience, [4][5][6] disease, 7 infant 8 and hyperscanning studies 9 due to its°exibility and high ecological validity, and obtained signi¯cant results. In studies using Á[HbO2] and Á[Hb] to represent the brain activity, heartbeat is the most dominant physiological noise, and should be¯ltered or removed directly.…”