Cerebrovascular response time to a breath-holding challenge

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...