Lesion patterns and stroke mechanisms in concurrent atherosclerosis of intracranial and extracranial vessels.
OBJECTIVE
Concurrent atherosclerosis of the intracranial and extracranial cerebrovascular system is common in Asians. The typical lesion patterns and the mechanisms of stroke in patients with concurrent stenoses are unclear. This study aimed to determine these stroke features of such patients in Hong Kong.


METHODS
We conducted a cross-sectional cohort study in a university hospital from January 2002 to December 2003. Consecutive Chinese patients with acute ischemic stroke underwent CT brain, MRI brain (with MR angiography and diffusion-weighted imaging sequences), and carotid duplex.


RESULTS
In total, 251 patients were included in the analysis. Of these, 109 (43%) had concurrent stenoses. Patients who had concurrent stenoses, as compared with those without concurrent stenoses, had more symptomatic stenoses (84% versus 58%; OR, 4.0; 95% CI, 2.1 to 7.3; P<0.001), more concomitant perforating artery infarct, pial infarct, and borderzone infarct (14% versus 4%; OR, 3.6; 95% CI, 1.4 to 9.7; P=0.007), more multiple diffusion-weighted imaging lesions (55% versus 37%; OR, 2.1; 95% CI, 1.3 to 3.4; P=0.005), and more infarcts in the territory of the leptomeningeal branches of middle cerebral artery (26% versus 13%; OR, 2.2; 95% CI, 1.2 to 4.3; P=0.01). In multivariate regression analysis, smoking; prior stroke; the presence of concomitant pial infarct, pial infarct, and borderzone infarcts; multiple diffusion-weighted imaging lesions; and symptomatic stenoses were significantly associated with concurrent stenoses. Among patients with concurrent stenoses, those who had tandem lesions, as compared with those who had nontandem lesions, had more perforating artery infarct and borderzone infarcts (27% versus 8%; OR, 4.3; 95% CI, 0.9 to 19.8; P=0.04); more concomitant pial infarct, pial infarct, and borderzone infarcts (18% versus 0%; P=0.02), and more multiple diffusion-weighted imaging lesions (65% versus 23%; OR, 6.2; 95% CI, 2.2 to 17.2; P<0.001). Infarcts in the territory of middle cerebral artery leptomeningeal branches and symptomatic stenoses were more common in patients with tandem lesions.


CONCLUSIONS
Concomitant perforating artery infarct, pial infarct, and borderzone infarcts; multiple diffusion-weighted imaging lesions, and infarcts in the leptomeningeal branches of the middle cerebral artery were more common in patients with concurrent stenoses, especially those with tandem lesions. This study suggested that the combination of hemodynamic compromise attributable to concurrent stenoses and artery-to-artery embolization is a common stroke mechanism in these patients.
Man
Bik Ling
BL
Division of Neurology, Department of Medicine and Geriatrics, Tuen Mun Hospital, Hong Kong, China. manbikling@gmail.com
Fu
Yat Pang
YP
Chan
Yin Yan
YY
Lam
Wynnie
W
Hui
Andrew Chi Fai
AC
Leung
Wai Hong
WH
Mok
Vincent
V
Wong
Ka Sing
KS
D000368:Aged; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000473:pathology*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D005260:Female; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging / Q000473:pathology*; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000473:pathology; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging / Q000473:pathology; D018810:Magnetic Resonance Angiography; D008297:Male; D008576:Meningeal Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex