Neurovascular decoupling: An early indicator of cognitive decline

Area of Science:

• Neurology
• Neuroimaging
• Cerebrovascular Health

Background:

• Alzheimer's disease (AD) cognitive decline is linked to cerebrovascular dysfunction, including small vessel disease (SVD).
• Current SVD MRI markers detect late-stage damage, missing early functional changes.
• Neurovascular coupling (NVC) indicates early cerebrovascular function but its longitudinal impact on cognition is unclear.

Purpose of the Study:

• To determine if baseline NVC predicts cognitive decline over 3.5 years.
• To assess NVC's association with cognitive changes in individuals with no complaints to mild cognitive impairment (MCI).

Main Methods:

• Seventy-five participants underwent cognitive tests and MRI with BOLD fMRI during visual stimulation to measure NVC.
• Cognitive decline was analyzed as a dichotomous (stable vs. decline) and continuous (domain-specific change) outcome.
• Logistic and linear regressions were used to analyze the association between baseline NVC and cognitive decline.

Main Results:

• Lower baseline NVC was significantly associated with global cognitive decline (dichotomous and continuous outcomes).
• NVC predicted decline in executive function but not other cognitive domains.
• Lacunar infarcts were the only conventional SVD MRI marker associated with cognitive decline.

Conclusions:

• Baseline NVC is a potential predictor of global cognitive decline in early AD.
• NVC may outperform traditional SVD MRI markers in predicting cognitive decline.
• NVC shows promise as a prognostic marker for early intervention in AD targeting cerebrovascular health.