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Updated: May 28, 2026
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Functional Transcranial Doppler Ultrasound for Monitoring Cerebral Blood Flow
Published on: March 15, 2021
Autonomic dysfunction in mild cognitive impairment: a transcranial Doppler study
G P Anzola1, S Galluzzi, S Mazzucco
1Service of Neurology, S. Orsola Hospital, Brescia, Italy. gianpaolo.anzola@poliambulanza.it
Acta Neurologica Scandinavica
|October 25, 2011
Summary
Patients with mild cognitive impairment (MCI) show normal cerebrovascular reactivity (CVR) but impaired heart rate (HR) response to CO2 challenges, suggesting autonomic dysfunction. This HR response may serve as an early marker for MCI.
Area of Science:
- Neurology
- Cardiology
- Vascular Medicine
Background:
- Mild cognitive impairment (MCI) pathogenesis involves unclear microvascular and autonomic derangements.
- Early detection of MCI is crucial for timely intervention and management.
Purpose of the Study:
- To evaluate cerebrovascular reactivity (CVR) and cardiac autonomic function in MCI patients using transcranial Doppler (TCD).
- To investigate potential early biomarkers for MCI detection.
Main Methods:
- Fifteen MCI patients and 28 controls underwent carotid ultrasound and TCD.
- CVR was assessed via middle cerebral artery mean flow velocity (MFV) during CO2 inhalation and hyperpnea.
- Heart rate (HR), mean arterial blood pressure (MAP), and end-tidal CO2 were monitored.
Main Results:
- No significant differences in MAP, end-tidal CO2, or MFV variations between groups.
- CVR was comparable between MCI patients and controls (P = 0.767).
- MCI patients exhibited blunted HR response to CO2 inhalation compared to controls.
Conclusions:
- MCI patients demonstrate normal CVR but exhibit signs of autonomic dysfunction upon CO2 challenge.
- The heart rate response to CO2 challenge may serve as a potential early marker for MCI.
- Further validation in larger studies is warranted to confirm these findings.
