title: Increased cerebral arterial pulsatility in patients with leukoaraiosis: arterial stiffness enhances transmission of aortic pulsatility.
abstract: OBJECTIVE
  Arterial stiffening reduces damping of the arterial waveform and hence increases pulsatility of cerebral blood flow, potentially damaging small vessels. In the absence of previous studies in patients with recent transient ischemic attack or stroke, we determined the associations between leukoaraiosis and aortic and middle cerebral artery stiffness and pulsatility.
  
  
  METHODS
  Patients were recruited from the Oxford Vascular Study within 6 weeks of a transient ischemic attack or minor stroke. Leukoaraiosis was categorized on MRI by 2 independent observers with the Fazekas and age-related white matter change scales. Middle cerebral artery (MCA) stiffness (transit time) and pulsatility (Gosling's index: MCA-PI) were measured with transcranial ultrasound and aortic pulse wave velocity and aortic systolic, diastolic, and pulse pressure with applanation tonometry (Sphygmocor).
  
  
  RESULTS
  In 100 patients, MCA-PI was significantly greater in patients with leukoaraiosis (0.91 versus 0.73, P<0.0001). Severity of leukoaraiosis was associated with MCA-PI and aortic pulse wave velocity (Fazekas: χ(2)=0.39, MCA-PI P=0.01, aortic pulse wave velocity P=0.06; age-related white matter change: χ(2)=0.38, MCA-PI P=0.015; aortic pulse wave velocity P=0.026) for periventricular and deep white matter lesions independent of aortic systolic blood pressure, diastolic blood pressure, and pulse pressure and MCA transit time with MCA-PI independent of age. In a multivariate model (r(2)=0.68, P<0.0001), MCA-PI was independently associated with aortic pulse wave velocity (P=0.016) and aortic pulse pressure (P<0.0001) and inversely associated with aortic diastolic blood pressure (P<0.0001) and MCA transit time (P=0.001).
  
  
  CONCLUSIONS
  MCA pulsatility was the strongest physiological correlate of leukoaraiosis, independent of age, and was dependent on aortic diastolic blood pressure and pulse pressure and aortic and MCA stiffness, supporting the hypothesis that large artery stiffening results in increased arterial pulsatility with transmission to the cerebral small vessels resulting in leukoaraiosis.
authors.affiliation: Stroke Prevention Research Unit, University of Oxford, Oxford, UK.
authors.forename: Alastair J S
authors.initials: AJ
authors.lastname: Webb
authors.forename: Michela
authors.initials: M
authors.lastname: Simoni
authors.forename: Sara
authors.initials: S
authors.lastname: Mazzucco
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kuker
authors.forename: Ursula
authors.initials: U
authors.lastname: Schulz
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rothwell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000000981:diagnostic imaging / Q000503:physiopathology*; D062186:Arterial Pressure / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000503:physiopathology*; D049292:Leukoaraiosis / Q000503:physiopathology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D063177:Pulse Wave Analysis; D020521:Stroke / Q000503:physiopathology*; D017585:Ultrasonography, Doppler, Transcranial; D059289:Vascular Stiffness / Q000502:physiology*