title: Dynamic cerebral autoregulation is compromised in ischaemic stroke of undetermined aetiology only in the non-affected hemisphere.
abstract: OBJECTIVE
  To assess dynamic cerebral autoregulation (CA) in patients with acute ischaemic stroke of undetermined aetiology, within 72h of stroke onset.
  
  
  METHODS
  In 6 patients with ischaemic stroke of undetermined aetiology (aged 66±9 years, National Institutes of Health Stroke Scale [NIHSS] score on admission: 4.0, range: 4-11), selected based on screening of 118 consecutive ischaemic stroke patients and in 14 volunteers (aged 62±10 years), we continuously monitored RR intervals (RRI), mean arterial pressure (MAP) by means of photoplethysmography, mean cerebral blood flow velocity (CBFV) using transcranial Doppler ultrasonography, end-tidal CO2 (ETCO2) and respiration during 2-min deep breathing paced at 6min(-1) (0.1Hz). To assess CA, we evaluated the impact of breathing-induced MAP oscillations on fluctuations of CBFV in the hemispheres with stroke, the non-involved hemispheres and randomly selected hemispheres of controls by applying cross-spectral analysis and calculating coherence, transfer function gain (CBFV-MAP gain) and phase shift angle between the two oscillating signals.
  
  
  RESULTS
  Phase shift angle between MAP and CBFV oscillations showed values >0 and was significantly reduced in the hemispheres without stroke as compared to controls (0.39±0.95 vs. -1.59±0.33rad, p=0.015), whereas in the hemispheres with stroke, phase shift angle did not differ significantly from that observed in the control hemispheres. Clinical status of stroke patients significantly improved at discharge from the hospital (NIHSS: 2.0, range: 1-8, p=0.028).
  
  
  CONCLUSIONS
  During the first days of ischaemic stroke of undetermined aetiology, dynamic cerebral autoregulation is compromised in the non-affected hemisphere, but not in the hemisphere with ischaemic lesion.
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland. Electronic address: mtutaj@tlen.pl.
authors.forename: Marcin
authors.initials: M
authors.lastname: Tutaj
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Miller
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Krakowska-Stasiak
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Piątek
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Hebda
authors.affiliation: Institute of Biomedical Engineering and Instrumentation, Wrocław University of Technology, Wrocław, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Lątka
authors.affiliation: Dept. of Mathematical Statistics, University of Agriculture, Cracow, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Strojny
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Szczudlik
authors.affiliation: Dept. of Neurology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Słowik
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D002545:Brain Ischemia / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002985:Clinical Protocols; D003430:Cross-Sectional Studies; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017156:Photoplethysmography; D011897:Random Allocation; D012720:Severity of Illness Index; D020521:Stroke / Q000503:physiopathology*; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
keywords: Autonomic system; Cerebral autoregulation; Cross-spectral analysis; Deep breathing; Phase shift; Stroke