Low frequency oscillations in cephalic vessels assessed by near infrared spectroscopy
Journal
European Journal of Clinical Investigation
Journal Volume
42
Journal Issue
11
Pages
1180-1188
Date Issued
2012
Author(s)
Abstract
Background and Methods Low frequency oscillations (LFO) of cerebral vessels are believed to reflect cerebral autoregulation. We investigated day-to-day and hemispheric variations in 0·1Hz LFO with near infrared spectroscopy (NIRS) and transcranial Doppler (TCD) to determine phase shift and gain of oxygenated haemoglobin (oxyHb) and the velocity of the middle cerebral artery (Vmca) to the arterial blood pressure (ABP). The direct left-right phase shifts of oxyHb and Vmca were also assessed. We examined 44 healthy volunteers by simultaneous recordings of ABP, oxyHb and Vmca during spontaneous and paced breathing at 6 breaths per minute on two separate days. Results The variation between hemispheres had a prediction interval (PI) of ±39° for ABP-oxyHb phase shift and ±69% for gain. ABP-Vmca showed ±57° PI phase shift and ±158% PI for gain. The variation from day to day showed ±61° PI for ABP-oxyHb phase shift and ±297% PI for gain. ABP-Vmca showed ±45° PI phase shift and ±166% PI for gain. We found a linear relation between phase shift of oxyHb and Vmca at paced breathing (P=0·0005), but not at rest (P=0·235). Conclusion Our results show that LFO phase shift ABP-oxyHb may be used as a robust measurement of differences in autoregulation between hemispheres and over time. In addition, we found a strong relation between oxyHb and Vmca during paced breathing. Gain showed too large variation for clinical use, as the SD was up to 100-fold of mean values. ? 2012 Stichting European Society for Clinical Investigation Journal Foundation.
Subjects
oxyhemoglobin
adult
aged
arterial pressure
article
autoregulation
brain blood vessel
breathing
end tidal carbon dioxide tension
female
hemisphere
human
human experiment
low frequency oscillation
male
middle cerebral artery
near infrared spectroscopy
normal human
oscillation
priority journal
transcranial doppler
Adult
Aged
Arterial Pressure
Blood Flow Velocity
Cerebrovascular Circulation
Female
Homeostasis
Humans
Male
Middle Aged
Middle Cerebral Artery
Oxyhemoglobins
Respiration
Spectroscopy, Near-Infrared
Ultrasonography, Doppler, Transcranial
SDGs
Type
journal article