Title:The Interaction of Dynamic Cerebral Autoregulation and Neurovascular
Coupling in Cognitive Impairment
Volume: 18
Issue: 14
关键词:
自动调节指数、痴呆、认知障碍、健康老年人、脑血流量、认知。
摘要:
Background: Dynamic cerebral autoregulation (dCA) remains intact in both ageing and
dementia, but studies of neurovascular coupling (NVC) have produced mixed findings.
Objective: We investigated the effects of task-activation on dCA in healthy older adults (HOA),
and patients with mild cognitive impairment (MCI) and Alzheimer’s Disease (AD).
Methods: Resting and task-activated data from thirty HOA, twenty-two MCI, and thirty-four AD
were extracted from a database. The autoregulation index (ARI) was determined at rest and during
five cognitive tasks from transfer function analysis. NVC responses were present where group-specific
thresholds of cross-correlation peak function and variance ratio were exceeded. Cumulative response
rate (CRR) was the total number of positive responses across five tasks and two hemispheres.
Results: ARI differed between groups in dominant (p=0.012) and non-dominant (p=0.042) hemispheres
at rest but not during task-activation (p=0.33). ARI decreased during language and memory
tasks in HOA (p=0.002) but not in MCI or AD (p=0.40). There was a significant positive correlation
between baseline ARI and CRR in all groups (r=0.26, p=0.018), but not within sub-groups.
Conclusion: dCA efficiency was reduced in task-activation in healthy but not cognitively impaired
participants. These results indicate differences in neurovascular processing in healthy older adults
relative to cognitively impaired individuals.