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Updated: Jul 10, 2026
MRI Mapping of Cerebrovascular Reactivity via Gas Inhalation Challenges
Published on: December 17, 2014
Cerebrovascular response time to a breath-holding challenge
G Gahn1, U Hallmeyer-Elgner, S Becker
1Klinik und Poliklinik für Neurologie, Universitatsklinikum Carl Gustav Carus der Technischen Universität, Dresden, Germany. gahn@rcs.urz.tu-dresden.de
Background:
To evaluate the timecourse of cerebrovascular reserve response to breath-holding.
Patients And Methods:
Using simultaneous bilateral transcranial Doppler (TCD) recordings from the MCA during a breath-holding challenge, we measured the time interval between baseline and peak blood flow velocity values in 25 patients with critical unilateral internal carotid artery (ICA) stenosis (> 85% lumen diameter reduction), in 9 patients with a non-critical (70-85%) ICA-stenosis and in 27 normal controls.
Results:
Normal controls and patients with non-critical stenosis reached peak MCA velocities on both sides almost simultaneously. For the patients with critical stenosis the peak response time ipsilateral to the stenosis was delayed 2.40 +/- 3.43 sec compared to the opposite side. This delay resolved after carotid endarterectomy.
Conclusions:
In response to a breath-holding challenge unilateral critical ICA stenosis is associated with a significant ipsilateral prolongation of the rise time from baseline to peak MCA velocity.
