Spontaneous oscillation of oxy- and deoxy- hemoglobin changes with a phase difference throughout the occipital cortex of newborn infants observed using non-invasive optical topography

Abstract We investigated spontaneous changes in the cerebral oxygenation state of infants during quiet sleeping by using a form of multi-channel near-infrared spectroscopy: non-invasive optical topography. Eight infants born at 32–39 weeks were studied at postconceptional term age (38–43 weeks). Spatially synchronized oscillations of changes in the concentration of oxy- and deoxy- hemoglobin ([oxy–Hb] and [deoxy–Hb]) were observed throughout the occipital cortex. Time series analysis based on the theory of non-linear oscillators showed that the mean periods of the oscillation for each infant ranged from 11 to 18 s. The phase lag of [oxy–Hb] relative to [deoxy–Hb] was stable at about 3π/4 . This phase difference may result from interplay between the vasomotion and the oxygen consumption in relation to brain activity.