[Cerebral reserve. A method for evaluating cerebro-vascular hemodynamic risk]

Area of Science:

• Neurology
• Vascular Medicine
• Medical Imaging

Context:

• Cerebrovascular pathology involves both embolic and hemodynamic risks, with challenges in quantifying arterial lesion impacts.
• Cerebral vascular reserve, defined as the ratio of maximum to baseline blood flow, is a key indicator of hemodynamic status.
• Traditional methods like positron emission transaxial tomography (PET) for assessing cerebral reserve are complex and difficult to implement.

Purpose:

• To explore the role of hemodynamic risk in cerebrovascular diseases.
• To investigate methods for accurately estimating the repercussions of arterial lesions on cerebral blood flow.
• To develop and validate new protocols for assessing cerebral vascular reserve and autoregulation.

Summary:

• Cerebral vascular reserve is measured by the ratio of maximum to baseline flow, with maximum flow induced by 5% CO2 inhalation.
• Positron emission transaxial tomography identified three stages of cerebral reserve: hemodynamic reserve, extraction reserve (critical zone), and ischemia.
• Emerging protocols utilizing transcranial Doppler aim to define an 'autoregulation reserve limit' for improved assessment of arterial lesion effects.

Impact:

• Advancements in assessing hemodynamic risk provide a more comprehensive understanding of cerebrovascular pathology.
• Development of transcranial Doppler protocols offers a more accessible method for evaluating the impact of arterial lesions.
• Improved hemodynamic risk assessment through combined explorations can lead to better patient management and treatment strategies.