Near-infrared spectroscopy and polysomnography during all-night sleep in human subjects

摘要

We have performed cerebral near-infrared spectroscopy (NIRS) and polysomnography (electro-encephalography, electro-oculography, electro-myography, pulse oximetry, and respiratory monitoring) during all-night sleep in five human subjects. Polysomnography data were used for sleep staging, while NIRS data were used to measure the concentration arid the oxygen saturation of hemoglobin in the frontal brain region. Immediately after sleep onset we observed a decrease in the cerebral concentration of oxy-hemoglobin ([HbO_2]) and an increase in the concentration of deoxy-hemoglobin ([Hb]), consistent with a decrease in the cerebral blood flow velocity or an increase in the cerebral metabolic rate of oxygen. An opposite trend (increase in [HbO_2] and decrease in [Hb]) was usually observed after transition to deep sleep (stages Ⅲ and Ⅳ). During rapid eye movement (REM) sleep, we observed an increase in [HbO_2] and decrease in [Hb], consistent with an increase in the cerebral blood flow that overcompensates the increase in the metabolic rate of oxygen associated with REM sleep.