Association Between Gas-Free Cerebrovascular Reactivity (CVR) and Cognitive Function in Older Adults With a High Risk...

Area of Science:

• Neurology
• Radiology
• Cognitive Science

Background:

• Vascular cognitive impairment and dementia (VCID) is a leading cause of dementia.
• Cerebrovascular reactivity (CVR) is a potential biomarker for VCID.
• Current CVR measurement requires a hypercapnia challenge, limiting clinical application.

Purpose of the Study:

• To evaluate intermittent breath modulation (bm-CVR) as a gas-free method for measuring CVR.
• To determine if bm-CVR can serve as a sensitive biomarker for VCID.

Main Methods:

• Prospective cohort study of 82 participants (normal cognition, mild cognitive impairment, mild dementia).
• CVR measured using 3.0T BOLD MRI with intermittent breath modulation.
• Cognitive function assessed via MoCA, domain-specific scores, and a composite score; physical function via gait speed and chair-stand tests.
• Multi-linear regression analyses were used to correlate bm-CVR with cognitive and physical measures.

Main Results:

• Whole-brain bm-CVR was significantly associated with diagnostic group (normal, MCI, dementia) and lower in impaired participants.
• Bm-CVR positively correlated with global cognitive scores (MoCA, composite).
• Bm-CVR was significantly associated with processing speed and language, but not executive function or episodic memory.

Conclusions:

• Gas-free bm-CVR is a sensitive biomarker for VCID.
• This method offers a more practical alternative to hypercapnia-based CVR for assessing vascular pathology.
• Bm-CVR may aid in the early detection and characterization of VCID.