Caffeine Can Affect Velocity in the Middle Cerebral Artery During Hyperventilation, Hypoventilation, and Thinking: A Transcranial Doppler Study

Citations Over Time

Abstract

This study examined possible caffeine-mediated changes in blood flow velocity in the middle cerebral artery (VMCA) induced by tests of cerebrovascular responsiveness. Transcranial Doppler (TCD) sonography provided simultaneous bilateral VMCA measures while healthy college students hypoventilated, hyperventilated, and performed cognitive activities (short-term remembering, generating an autobiographical image, solving problems), each in 31-second tests. VMCA measures were obtained from the same persons, in separate testing sessions, when they were noncaffeinated and under two levels of caffeine: a smaller amount (from a cola, 45 mg/12 oz) and a larger amount (from coffee, 117 mg/8 oz). Compared with the no-caffeine control condition, a smaller amount of caffeine had no significant effects on global VMCA, but a larger amount suppressed VMCA by 5.8%. Time-course analyses showed that VMCA (1) followed a triphasic pattern to increase over baselines during hypoventilation regardless of caffeine condition, (2) slowed below baselines during hyperventilation (with the degree of slowing attenuated under caffeine), and (3) increased over baselines during all cognitive activities (ranges 3.8-6.9%). It is concluded that a large amount of caffeine can suppress VMCA, and this possibility should be anticipated when TCD is used to assess cerebral hemovelocity.

Related Papers

• → The Effect of Black Tea and Caffeine on Regional Cerebral Blood Flow Measured with Arterial Spin Labeling(2013)60 cited
• → Regional Cerebral Blood Flow and Cerebral Metabolic Rate of Oxygen during Hyperventilation in the Newborn Dog(1986)47 cited
• → Transcranial Doppler Findings of Cerebral Vasospasm in Preeclampsia(1996)4 cited
• → Transcranial Doppler Monitoring of Middle Cerebral Artery Blood Flow Velocities During Three Memory Tasks(1992)9 cited
• → THE EFFECT OF CONTROLLED HYPERVENTILATION ON CEREBRAL BLOOD FLOW AND OXYGEN UPTAKE IN PATIENTS WITH BRAIN LESIONS(1974)1 cited