title: Dynamic cerebral autoregulation following acute ischaemic stroke: Comparison of transcranial Doppler and magnetic resonance imaging techniques.
abstract: Novel MRI-based dynamic cerebral autoregulation (dCA) assessment enables the estimation of both global and spatially discriminated autoregulation index values. Before exploring this technique for the evaluation of focal dCA in acute ischaemic stroke (AIS) patients, it is necessary to compare global dCA estimates made using both TCD and MRI. Both techniques were used to study 11 AIS patients within 48 h of symptom onset, and nine healthy controls. dCA was assessed by the rate of return of CBFV (Rturn) following a sudden drop induced by the thigh cuff manoeuvre. No significant between-hemisphere differences were seen in controls using either the TCD or MRI technique. Inter-hemisphere averaged Rturnvalues were not different between TCD (1.89 ± 0.67%/s) and MRI (2.07 ± 0.60%/s) either. In patients, there were no differences between the affected and unaffected hemispheres whether assessed by TCD (Rturn0.67 ± 0.72 vs. 0.98 ± 1.09%/s) or MRI (0.55 ± 1.51 vs. 1.63 ± 0.63%/s). Rturnfor both TCD and MRI was impaired in AIS patients compared to controls in both unaffected and affected hemispheres (ANOVA, p = 0.00005). These findings pave the way for wider use of MRI for dCA assessment in health and disease.
authors.affiliation: Ageing and Stroke Medicine, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK rp9@le.ac.uk.|NIHR Biomedical Research Unit for Cardiovascular Sciences, University of Leicester, Leicester, UK.
authors.forename: Ronney B
authors.initials: RB
authors.lastname: Panerai
authors.affiliation: Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile.
authors.forename: José L
authors.initials: JL
authors.lastname: Jara
authors.affiliation: Ageing and Stroke Medicine, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.
authors.forename: Nazia P
authors.initials: NP
authors.lastname: Saeed
authors.affiliation: Ageing and Stroke Medicine, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.|NIHR Biomedical Research Unit for Cardiovascular Sciences, University of Leicester, Leicester, UK.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Horsfield
authors.affiliation: Ageing and Stroke Medicine, Department of Cardiovascular Sciences, University of Leicester, Leicester, UK.|NIHR Biomedical Research Unit for Cardiovascular Sciences, University of Leicester, Leicester, UK.
authors.forename: Thompson G
authors.initials: TG
authors.lastname: Robinson
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002545:Brain Ischemia / Q000503:physiopathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006706:Homeostasis; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000503:physiopathology*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods / Q000592:standards*
keywords: Acute ischaemic stroke; cerebral autoregulation; magnetic resonance imaging; thigh cuff; transcranial Doppler ultrasound