title: Ultrasound Tissue Pulsatility Imaging Suggests Impairment in Global Brain Pulsatility and Small Vessels in Elderly Patients with Orthostatic Hypotension.
abstract: BACKGROUND
  Orthostatic hypotension (OH) is highly prevalent in the elderly, and this population can be exposed to serious complications, including falls and cognitive disorders, as well as overall mortality. However, the pathophysiology of OH is still poorly understood, and innovative methods of cerebral blood flow (CBF) assessment have been required to accurately investigate cerebrovascular reactivity in OH.
  
  
  OBJECTIVE
  We want to compare brain tissue pulsatility (BTP) changes during an orthostatic challenge in elderly patients over 80 with and without OH.
  
  
  METHODS
  Forty-two subjects aged 80 and over were recruited from the geriatric unit of the Hospital of Tours, France, and were divided into two groups according to the result of an orthostatic challenge. The noninclusion criteria were any general unstable medical condition incompatible with orthostatic challenge, having no temporal acoustic window, severe cognitive impairment (Mini Mental Status Examination <15), history of stroke, and legal guardianship. We used the novel and highly sensitive ultrasound technique of tissue pulsatility imaging to measure BTP changes in elderly patients with (n = 22) and without OH (n = 17) during an orthostatic challenge.
  
  
  RESULTS
  We found that the mean brain tissue pulsatility related to global intracranial pulsatility, but not maximum brain tissue pulsatility related to large arteries pulsatility, decreased significantly in OH patients, with a delay compared with the immediate drop in peripheral blood pressure.
  
  
  CONCLUSIONS
  Global pulsatile CBF changes and small vessels pulsatility, rather than changes in only large arteries, may be key mechanisms in OH to account for the links between OH and cerebrovascular disorders.
authors.affiliation: Médecine Gériatrique, CHRU de Tours, Tours, France. Electronic address: 12biogeau@dumg-tours.fr.
authors.forename: Julie
authors.initials: J
authors.lastname: Biogeau
authors.affiliation: Clinique Psychiatrique Universitaire, CHRU de Tours, Tours, France; UMR Inserm U930, Université François Rabelais, Tours, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Desmidt
authors.affiliation: Inserm CIC 1415, CHRU de Tours, Tours, France.
authors.forename: Paul-Armand
authors.initials: PA
authors.lastname: Dujardin
authors.affiliation: UMR Inserm U930, Université François Rabelais, Tours, France.
authors.forename: Redouane
authors.initials: R
authors.lastname: Ternifi
authors.affiliation: Département de Médecine Interne, CHRU de Tours, Tours, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Eudo
authors.affiliation: UMR Inserm U930, Université François Rabelais, Tours, France; Inserm CIC 1415, CHRU de Tours, Tours, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Vierron
authors.affiliation: UMR Inserm U930, Université François Rabelais, Tours, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Remenieras
authors.affiliation: UMR Inserm U930, Université François Rabelais, Tours, France; Inserm CIC 1415, CHRU de Tours, Tours, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Patat
authors.affiliation: Clinique Psychiatrique Universitaire, CHRU de Tours, Tours, France; UMR Inserm U930, Université François Rabelais, Tours, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Camus
authors.affiliation: Médecine Gériatrique, CHRU de Tours, Tours, France; Université François-Rabelais de Tours, Tours, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Constans
mesh_terms: D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001795:Blood Pressure Determination; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D004453:Echoencephalography; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D008609:Mental Status Schedule; D011187:Posture / Q000502:physiology
keywords: Orthostatic hypotension; cerebral autoregulation; neuroimaging; ultrasound