RESUMO
BACKGROUND: There are conflicting evidences on endothelial function in lacunar infarction. This may be attributed to the effects of risk factors on the vascular smooth muscle. To test endothelial function only in patients with lacunar infarction, we evaluated the endothelium-dependent and -independent vasodilatation of the brachial artery. METHODS: We enrolled consecutive patients with lacunar infarction defined by clinical characteristics and MRI findings. The control group included age- and sex-matched patients with hypertension who do not have any history of clinical stroke, coronary artery disease or peripheral vascular disease. Endothelial function was evaluated using flow-mediated dilatation (FMD) and nitrogen-mediated dilatation (NMD) of the brachial artery. FMD and NMD were examined by an experienced vascular sonographer using a high-resolution ultrasound. Intracranial stenosis was defined as flow gap or >50% reduction in vessel diameter on MRA. RESULTS: FMD was 6.6 +/- 4.5% in the lacunar infarction group and 12.2 +/- 4.6% in the control group (p = 0.000). NMD was 14.3 +/- 4.9% in the lacunar infarction group and 13.8 +/- 4.9% in the control group (p = 0.37). FMD in patients with lacunar infarction and intracranial arterial stenosis was 6.4 +/- 3.9%, and FMD in patients with lacunar infarction was only 6.9 +/- 5.5%. In the control group, it was 12.2 +/- 4.6%. CONCLUSION: FMD was low in patients with lacunar infarction. NMD was similar between the lacunar infarction group and the control group. These results are suggestive of pure endothelial dysfunction in lacunar infarction. Endothelial dysfunction was as severe in lacunar infarction as in intracranial arterial stenosis.
