Background: Cerebral hemodynamic features of patients with different types of acute ischemic stroke are still obscure. We compared cerebral vasomotor reactivity (VMR) in acute cortical (CI) and subcortical (SI) brain infarcts.
Methods: Acute stroke patients (within 72 h of stroke onset) underwent transcranial Doppler and the Diamox test (1 g acetazolamide IV). The percent difference between blood flow velocities in the middle cerebral arteries before and after acetazolamide was defined as VMR%. CI and SI infarcts were confirmed by computerized tomography and/or magnetic resonance imaging. Clinical status and disability were assessed by means of the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) respectively.VMR% values and stroke severity and disability parameters were compared between CI and SI groups using ANOVA and Pearson's correlation (r) coefficients.
Results: VMR% values of the ipsilateral side to the brain infarct in the CI group were significantly lower as compared with SI group (12.2+/-15.9% and 25.6+/-24.4% respectively, P=0.03). VMR% values in both groups were not correlated with stroke severity and disability (P<0.2).
Conclusions: Our results suggest greater vulnerability of resistance arterioles in the setting of cortical gray matter infarcts. Although gray matter VMR is physiologically higher than white matter VMR, patients with acute CI have impaired cerebral vascular reserve.