title: Cerebral autoregulation: an overview of current concepts and methodology with special focus on the elderly.
abstract: Cerebral autoregulation (CA) refers to the properties of the brain vascular bed to maintain cerebral perfusion despite changes in blood pressure (BP). Whereas classic studies have assessed CA during changes in BP that have a gradual onset, dynamic studies quantify the fast modifications in cerebral blood flow (CBF) in relation to rapid alterations in BP. There is a lack of standardization in the assessment of dynamic CA. This review provides an overview of the methods that have been applied, with special focus on the elderly. We will discuss the relative merits and shortcomings of these methods with regard to the aged population. Furthermore, we summarize the effects of variability in BP on CBF in older people. Of the various dynamic assessments of CA, a single sit-to-stand procedure is a feasible and physiologic method in the elderly. The collection of spontaneous beat-to-beat changes in BP and CBF allows estimation of CA using the technique of transfer function analysis. A thorough search of the literature yielded eight studies that have measured dynamic CA in the elderly aged <75 years. Regardless of the methods used, it was concluded from these studies that CA was preserved in this population.
authors: Department of Geriatric Medicine, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
authors: Arenda Hea
authors: AH
authors: van Beek
authors: Jurgen Ahr
authors: JA
authors: Claassen
authors: Marcel Gm Olde
authors: MG
authors: Rikkert
authors: René Wmm
authors: RW
authors: Jansen
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D013997:Time Factors