Characteristics of Internal Carotid Artery Stenosis in Patients with Acute Ischemic Stroke

Background : It has been known that Asians are more likely to develop atherosclerosis of the intracranial arteries while Caucasians have more extracranial arterial diseases. Angiographic distribution and frequency of the carotid artery stenosis have not been well known in Korean patients with acute ischemic stroke. Methods : From the Yonsei Stroke Registry, a total of 300 acute ischemic stroke patients, who were evaluated by a conventional cerebral angiography from July 1997 to September 2000, were enrolled for this study. Patients were divided into three groups: isolated intracranial internal carotid artery (ICA) stenosis (IICA group); isolated extracranial ICA stenosis (EICA group); and combined stenosis of intracranial and extracranial ICAs (combined group). The clinical and angiographical characteristics were investigated and compared among them. Results : A total of 107 patients had stenotic lesions in the ICA. They were 45 patients with lesions in the intracranial ICA (IICA group), 42 in the extracranial ICA (EICA group), and 20 patients in the both intracranial and extracranial ICAs (combined group). No significant differences were found among the three groups in terms of the degree of stenosis (50.2%, 49.6%, 56.8% each: p= 0.34), risk factors of ischemic stroke, and frequency of combined stenosis in the other intracranial arteries. Conclusions : ICA stenosis was common in patients with acute ischemic stroke. Significant differences of the frequency and risk factors between intracranial and extracranial ICA stenosis were not found. ICA stenosis at the extracranial portion as well as at the intracranial portion should be considered as a common cause of ischemic stroke occurring in the carotid artery system.