Age differences in spontaneous cerebrovascular reactivity at rest

Area of Science:

• Neuroscience
• Vascular Biology
• Aging Research

Background:

• Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) are crucial for brain health.
• Age-related changes in CVR are not fully understood, with mixed findings in prior research.
• Spontaneous CVR (sCVR) at rest has not been studied across age groups.

Purpose of the Study:

• To compare whole brain and regional sCVR at rest between healthy younger and cognitively unimpaired older adults.
• To investigate age-related differences in sCVR and its relationship with CBF variability.
• To determine if sCVR can indicate cerebrovascular aging in unimpaired individuals.

Main Methods:

• Compared sCVR at rest in 24 healthy younger adults (18-34 years) and 163 cognitively unimpaired older adults (55-87 years).
• Assessed both whole brain and regional sCVR.
• Analyzed age differences in sCVR and cerebral blood flow (CBF) variability.

Main Results:

• Older adults exhibited significant deficits in whole brain and regional sCVR at rest compared to younger adults.
• Medial temporal lobe regions showed the most pronounced age-related differences in sCVR.
• Age differences in sCVR and CBF variability were more substantial than differences in mean CBF.

Conclusions:

• Age-related deficits in sCVR are present in cognitively unimpaired older adults.
• sCVR may serve as an indicator of cerebrovascular aging.
• Further research on sCVR could aid early detection of age-related vascular dysfunction.