Spontaneous and endothelial-independent vasodilation are impaired in patients with spontaneous carotid dissection: a case-control study.

BACKGROUND AND PURPOSE We undertook this case-control study in patients with unilateral spontaneous dissection of the cervical internal carotid artery to investigate spontaneous and endothelium-independent dilation of the nondissected, contralateral carotid arteries and the ipsilateral brachial artery using high-resolution ultrasound. METHODS Spontaneous and endothelial-independent (nitroglycerin-mediated) absolute and relative dilation were assessed in the internal and common carotid and brachial arteries of 27 patients with unilateral spontaneous dissection of the cervical internal carotid artery and 27 age- and sex-matched healthy controls. RESULTS Absolute and relative spontaneous and endothelial-independent dilation of the carotid, but not brachial arteries, were significantly lower in patients as compared with controls. CONCLUSIONS Vasodilation abnormalities may be a predisposing factor for spontaneous dissection of the cervical internal carotid artery.