High Extent of Intracranial Carotid Artery Calcification Is Associated with Downstream Microemboli in Stroke Patients.
BACKGROUND
Intracranial arterial calcification (ICAC) is frequently detected on head computed tomography and has been found to be associated with ischemic stroke by recent clinical studies.


OBJECTIVE
Based on a hospital-based study, we aimed to compare the occurrence of cerebral microembolic signals (MES) among stroke patients with different degrees of ICAC, which may indicate the potential mechanisms linking ICAC and ischemic stroke in intracranial atherosclerosis patients.


METHODS
This is a post-hoc analysis of our previous clinical study in 2005-2007, recruiting consecutive ischemic stroke patients with middle cerebral artery territory infarctions and good temporal window for MES monitoring. The degrees of ICAC in the Circle of Willis, especially calcification in the ipsilateral intracranial internal carotid artery (iICA), were evaluated both qualitatively and quantitatively on unenhanced head computed tomography.


RESULTS
Among the 68 recruited patients, MES was detected in 26 patients (38.24%). The overall degree of ICAC in the Circle of Willis was similar between patients with and without MES. For calcification in ipsilateral iICA, the presence of MES was more frequent in the high extent group (widest arc of calcification ≥90°) than in the low extent group (54.2% versus 29.5%, P = .046). Logistic regression found that a high extent ipsilateral iICA calcification was an independent risk factor of MES (odds ratio: 3.134; 95% confidence interval, 1.029-9.543; P = .044).


CONCLUSIONS
MES is frequently detected in patients with a high extent of ipsilateral iICA calcification, which suggests that a high extent of iICA calcification indicates artery vulnerability and accounts for the occurrence of microemboli in the corresponding artery.
Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong SAR, China.
Xiao-Hong
XH
Wu
Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong SAR, China. Electronic address: fionachen@cuhk.edu.hk.
Xiang-Yan
XY
Chen
Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Yu-Hua
YH
Fan
Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong SAR, China.
Thomas Wai-Hong
TW
Leung
Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong SAR, China.
Ka-Sing
KS
Wong
D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000000981:diagnostic imaging*; D002537:Intracranial Arteriosclerosis / Q000150:complications / Q000000981:diagnostic imaging*; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000150:complications / Q000000981:diagnostic imaging*
Intracranial arterial calcification; atherosclerosis; microembolic signals; stroke