Dynamic cerebral autoregulation in acute lacunar and middle cerebral artery territory ischemic stroke.
OBJECTIVE
We addressed whether dynamic cerebral autoregulation (dCA) is affected in middle cerebral artery (MCA) territory (MCAS) and lacunar ischemic stroke (LS).


METHODS
Blood pressure (MAP) and MCA velocity (V) were measured in 10 patients with large MCAS (National Institutes of Health Stroke score, 17+/-2; mean+/-SEM), in 10 with LS (score, 9+/-1), and in 10 reference subjects. dCA was evaluated in time (delay of the MCA Vmean counter-regulation during changes in MAP) and frequency domains (cross-spectral MCA Vmean-to-MAP phase lead).


RESULTS
In reference subjects, latencies for MAP increments (5.3+/-0.5 seconds) and decrements (5.6+/-0.5 seconds) were comparable, and low frequency MCA Vmean-to-MAP phase lead was 56+/-5 and 59+/-5 degrees (left and right hemisphere). In MCAS, these latencies were 4.6+/-0.7 and 5.6+/-0.5 seconds in the nonischemic hemisphere and not detectable in the ischemic hemisphere. In the unaffected hemisphere, phase lead was 61+/-6 degrees versus 26+/-6 degrees on the ischemic side (P<0.05). In LS, no latency and smaller phase lead bilaterally (32+/-6 and 33+/-5 degrees) conformed to globally impaired dCA.


CONCLUSIONS
In large MCAS infarcts, dynamic cerebral autoregulation was impaired in the affected hemisphere. In LS, dynamic cerebral autoregulation was impaired bilaterally, a finding consistent with the hypothesis of bilateral small vessel disease in patients with lacunar infarcts.
Immink
Rogier V
RV
Cardiovascular Research Institute Amsterdam, Department of Physiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
van Montfrans
Gert A
GA
Stam
Jan
J
Karemaker
John M
JM
Diamant
Michaela
M
van Lieshout
Johannes J
JJ
D001783:Blood Flow Velocity; D001794:Blood Pressure; D020520:Brain Infarction / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005260:Female; D006706:Homeostasis; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology*; D014463:Ultrasonography