Den arterielle barorefleksens påvirkning av cerebral blodstrøm: et paradoks?

Abstract

Introduction: Maintenance of cerebral perfusion is crucial for oxygen- and nutrients supply. Therefore, it is essential to keep cerebral blood flow (CBF) constant across a range of blood pressures. During physiological challenges, integrated control of systemic blood pressure and CBF is needed to maintain cerebral perfusion, which are regulated by arterial baroreflex and cerebral autoregulation (CA), respectively. The purpose of this literature review is to determine the possible direct or indirect role of arterial baroreflex in cerebral blood flow regulation. Material and methods: We performed a non-systematic PubMed search with selected keywords and MeSH-terms which provided 173 publications. The search result was narrowed by publication date between 2000-2020 and language. In addition, a reference list consisting of 60 articles from a recent review was evaluated. Finally, application of exclusions criteria (patient- and animal studies) resulted in 11 relevant articles, 2 review and 9 original articles. Results: This review confirmed the existence of an inverse correlation between the baroreflex sensitivity (BRS) and dynamic CA in healthy young adults. However, this correlation diminished with aging. Although no significant impairment of dynamic CA was found with aging, results showed that attenuation of BRS was associated with aging. During dynamic exercise compared to rest, CBF increased and dynamic CA attenuated simultaneously. Therefore, the arterial baroreflex plays a major role in CBF regulation especially during exercise. Conclusions: Overall, our review supports the viewpoint that arterial baroreflex may play an important role in dynamic CBF regulation.

Introduction: Maintenance of cerebral perfusion is crucial for oxygen- and nutrients supply. Therefore, it is essential to keep cerebral blood flow (CBF) constant across a range of blood pressures. During physiological challenges, integrated control of systemic blood pressure and CBF is needed to maintain cerebral perfusion, which are regulated by arterial baroreflex and cerebral autoregulation (CA), respectively. The purpose of this literature review is to determine the possible direct or indirect role of arterial baroreflex in cerebral blood flow regulation. Material and methods: We performed a non-systematic PubMed search with selected keywords and MeSH-terms which provided 173 publications. The search result was narrowed by publication date between 2000-2020 and language. In addition, a reference list consisting of 60 articles from a recent review was evaluated. Finally, application of exclusions criteria (patient- and animal studies) resulted in 11 relevant articles, 2 review and 9 original articles. Results: This review confirmed the existence of an inverse correlation between the baroreflex sensitivity (BRS) and dynamic CA in healthy young adults. However, this correlation diminished with aging. Although no significant impairment of dynamic CA was found with aging, results showed that attenuation of BRS was associated with aging. During dynamic exercise compared to rest, CBF increased and dynamic CA attenuated simultaneously. Therefore, the arterial baroreflex plays a major role in CBF regulation especially during exercise. Conclusions: Overall, our review supports the viewpoint that arterial baroreflex may play an important role in dynamic CBF regulation.