Simultaneous assessment of cerebral oxygenation and hemodynamics during a motor task. A combined near infrared and transcranial Doppler sonography study.

During performance of a sequential finger opposition task we measured changes in regional cerebral blood oxygenation (rCBO) over the motor cortex and blood flow velocity changes (CBFV) in the middle cerebral artery in a combined near-infrared spectroscopy (NIRS) and transcranial Doppler Sonography (TCD) study. Stimulus duration was 60 followed by a 90 s rest period. During performance of the motor task we observed an increase in [oxy-Hb] a decrease in [deoxy-Hb] and an increase in MCA flow velocity. These changes were significantly more pronounced contralaterally than ipsilaterally to the moving hand. The time course of changes in [oxy-Hb] and CBFV were strikingly similar, showing a pronounced initial over-shoot. This study proves the feasibility of a simultaneous assessment of microcirculatory hemodynamics and cerebral oxygenation at high temporal resolution.