Cyclic alternating pattern is associated with cerebral hemodynamic variation: a near-infrared spectroscopy study of sleep in healthy humans

PLoS One. 2012;7(10):e46899. doi: 10.1371/journal.pone.0046899. Epub 2012 Oct 10.

Abstract

The cyclic alternating pattern (CAP), that is, cyclic variation of brain activity within non-REM sleep stages, is related to sleep instability and preservation, as well as consolidation of learning. Unlike the well-known electrical activity of CAP, its cerebral hemodynamic counterpart has not been assessed in healthy subjects so far. We recorded scalp and cortical hemodynamics with near-infrared spectroscopy on the forehead and systemic hemodynamics (heart rate and amplitude of the photoplethysmograph) with a finger pulse oximeter during 23 nights in 11 subjects. Electrical CAP activity was recorded with a polysomnogram. CAP was related to changes in scalp, cortical, and systemic hemodynamic signals that resembled the ones seen in arousal. Due to their repetitive nature, CAP sequences manifested as low- and very-low-frequency oscillations in the hemodynamic signals. The subtype A3+B showed the strongest hemodynamic changes. A transient hypoxia occurred during CAP cycles, suggesting that an increased CAP rate, especially with the subtype A3+B, which may result from diseases or fragmented sleep, might have an adverse effect on the cerebral vasculature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Arousal / physiology
  • Cerebral Cortex / blood supply*
  • Cerebral Cortex / physiology*
  • Cerebrovascular Circulation / physiology
  • Female
  • Heart Rate / physiology
  • Hemodynamics / physiology*
  • Humans
  • Male
  • Periodicity
  • Photoplethysmography
  • Polysomnography
  • Sleep / physiology*
  • Sleep Stages / physiology
  • Sleep, REM / physiology
  • Spectroscopy, Near-Infrared
  • Young Adult

Grants and funding

The study was financially supported by the Finnish Cultural Foundation (http://www.skr.fi/) and by the HUSLAB EVO funding (TLE82N0008). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.