Cerebral oxygenation changes in response to motor stimulation.
We studied cerebral hemodynamic response to a sequential motor task in 56 subjects to investigate the time course and distribution of blood oxygenation changes as monitored by near-infrared spectroscopy (NIRS). To address whether response is modulated by different performance velocities, a group of subjects (n = 12) was examined while performing the motor task at 1, 2, and 3 Hz. The results demonstrate that 1) the NIRS response reflects localized changes in cerebral hemodynamics, 2) the response, consisting of an increase in oxygenated hemoglobin concentration [oxy-Hb] and a decrease in deoxygenated hemoglobin concentration ([deoxy-Hb]), is lateralized and increases in amplitude with higher performance rates, and 3) changes in [oxy-Hb] and [deoxy-Hb] differ in time course. Changes in [oxy-Hb] are biphasic, with a fast initial increase and a pronounced poststimulus undershoot. The stimulus-associated decrease in [deoxy-Hb] is monophasic, and response latency is greater. We conclude that NIRS is able to detect even small changes in cerebral hemodynamic response to functional stimulation.
Obrig
H
H
Department of Neurology, Humboldt-Universität zu Berlin, Germany.
Hirth
C
C
Junge-Hülsing
J G
JG
Döge
C
C
Wolf
T
T
Dirnagl
U
U
Villringer
A
A
D000328:Adult; D002540:Cerebral Cortex / Q000378:metabolism*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
D010100:Oxygen