Cerebral oxygenation changes in response to motor stimulation.
Obrig, Hellmuth, Christina Hirth, Jan G. Junge-H[umlaut]ulsing,
Claudia D[diaeresis]oge, Tilo Wolf, Ulrich Dirnagl, Arno Villringer.
Department of Neurology, Charit[acute]e, Humboldt
-Universit[umlaut]at zu Berlin, 10098 Berlin, FR Germany
APStracts 3:0222A, 1996.
We studied cerebral haemodynamic response to a sequential motor task
in 56 subjects, to investigate the time course and the distribution
of blood oxygenation changes as monitored by near-infrared
spectroscopy (NIRS). To address the question whether response is
modulated by different performance velocities, a group of subjects
(n=12) was examined performing the motor task at 1, 2 and 3 Hz. The
results demonstrate that: (1) NIRS response reflects localized
changes in cerebral haemodynamics. (2) The response consisting of an
increase in oxygenated and a decrease in deoxygenated haemoglobin
concentration ([oxy-Hb] and [deoxy-Hb]) is lateralized and increases
in amplitude with higher performance rates. (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 post-stimulus
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 haemodynamic response
to functional stimulation.
Received 31 July 1995; accepted in final form 18 March 1996.
APS Manuscript Number A832-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 May 96