Dynamic cerebral autoregulation in Alzheimer’s disease and mild cognitive impairment: A systematic review

Rachel Heutz, Jurgen Claassen, Sanne Feiner, Aaron Davies, Dewakar Gurung, Ronney B. Panerai, Rianne de Heus, Lucy C. Beishon*

*Corresponding author for this work

Research output: Contribution to journalReview articleAcademicpeer-review

Abstract

Dynamic cerebral autoregulation (dCA) is a key mechanism that regulates cerebral blood flow (CBF) in response to transient changes in blood pressure (BP). Impairment of dCA could increase vulnerability to hypertensive vascular damage, but also to BP lowering effects of antihypertensive treatment. The literature remains conflicted on whether dCA is altered in Alzheimer’s disease (AD) and mild cognitive impairment (MCI). We summarized available data on dCA in AD and MCI, by searching PubMed, Embase, PsycINFO and Web of Science databases (inception-January 2022). Eight studies (total n = 443) were included in the qualitative synthesis of which seven were eligible for meta-analysis. All studies used Transcranial Doppler (TCD) ultrasonography and transfer function analysis or the autoregulatory index to assess dCA during spontaneous or induced BP fluctuations. Meta-analysis indicated no significant difference between AD, MCI and healthy controls in dCA parameters for spontaneous fluctuations. For induced fluctuations, the available data were limited, but indicative of at least preserved and possibly better autoregulatory functioning in AD and MCI compared to controls. In summary, current evidence does not suggest poorer dCA efficiency in AD or MCI. Further work is needed to investigate dCA in dementia with induced fluctuations controlling for changes in end-tidal carbon dioxide.
Original languageEnglish
JournalJournal of Cerebral Blood Flow and Metabolism
Early online date2023
DOIs
Publication statusE-pub ahead of print - 2023
Externally publishedYes

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