Background and purpose: Functional assessment of small arteries and arterioles could provide valuable information regarding the extent of diffuse arteriolosclerosis in patients with small-vessel disease. Therefore we attempted to clarify the role of cerebrovascular reactivity (CVR) as a risk marker for first-ever symptomatic lacunar infarction.
Methods: Forty-six patients with lacunar infarction and 46 sex- and age-matched control subjects were prospectively evaluated. Cerebral hemodynamics were studied with transcranial Doppler ultrasonography. CVR was examined by calculating the percent increase in mean flow velocity occurring after 15 mg/kg acetazolamide administration (Diamox test).
Results: CVR was significantly (P<0.0001, Student's t test) lower in cases (50.0+/-12. 7%) as compared with control subjects (65.2+/-12.4%). A multiple logistic regression analysis identified male sex (odds ratio [OR] 2. 3, P=0.02), age (OR 3.6, P<0.005), and the presence of lacunar infarction on magnetic resonance imaging (OR 5.3, P<0.001) as significant and independent factors associated with a reduction of CVR. Moreover, a cut-point of 55.6% (sensitivity 67%, specificity 82%) was established as the threshold value for distinguishing between pathological and normal CVR. CVR was significantly (P=0.02) lower in patients with multiple (46.38+/-12.6%) than with single (54. 83+/-11.58%) lacunar infarction. In addition, a trend of negative correlation was found between CVR and the number of lacunar infarctions (r=-0.26, P=0.08). In the multiple logistic model, history of hypertension (OR 7.24; 95% confidence interval 2.95 to 17. 79) and CVR (OR 0.8; 95% confidence interval 0.81 to 0.93) emerge as significant and independent predictors of first-ever lacunar infarction.
Conclusions: These data suggest that impaired CVR is a risk marker for first-ever lacunar infarction.