Associations of cerebral perfusion with infarct patterns and early neurological outcome in symptomatic intracranial atherosclerotic stenosis

Xiangming Xu¹Linfang Lan¹Zhuhao Li²Wenli Zhou¹Jing Yang¹Xinyi Leng^3*Yuhua Fan^1*

• ¹Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
• ²Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, Guangzhou, China
• ³Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China

Objectives Intracranial atherosclerotic stenosis (ICAS) is a major cause of ischemic stroke, with various infarct patterns. We aimed to investigate the cerebral perfusion features underlying different infarct patterns and the relationship between cerebral perfusion and early neurological outcome in symptomatic ICAS (sICAS).Methods Patients with 50-99% sICAS in anterior circulation were enrolled. Cerebral perfusion measures were obtained in CT perfusion images, such as the volumes of infarct core, penumbra defined with Tmax >6s and >4s, and penumbra-core mismatch.Infarct patterns in diffusion-weighted MR imaging were categorized into four categories: borderzone, perforator, territorial patterns and a mixed pattern. A favorable early neurological outcome was defined as decrease in NIHSS ≥1 point at discharge compared with admission.We recruited 144 patients (median age 66 years and 61.8% males). There was more significant perfusion compromise in those with borderzone or territorial infarcts, than those with perforator infarct pattern. Patients with a favorable early neurological outcome had smaller volumes of penumbra and penumbra-core mismatch at baseline. Multivariate logistic regression revealed that penumbra (defined by Tmax>4s)-core mismatch volume >15ml was independently associated with a lower chance of achieving a favorable early neurological outcome (adjusted odds ratio, 0.354, 95% confidence interval, 0.136-0.923, p=0.03).Conclusions Hemodynamic compromise likely underlies borderzone and territorial cortical/subcortical infarcts in patients with sICAS. The penumbra-infarct core mismatch volume in CT perfusion, using Tmax >4s to define the penumbra, was associated with early neurological outcomes of sICAS patients.CI Confidence interval CTP CT perfusion ICAS Intracranial atherosclerotic stenosis MCA Middle cerebral artery NIHSS National Institutes of Health Stroke Scale OR Odds ratio rCBF Relative cerebral blood flow rCBV Relative cerebral blood volume rMTT Relative mean transit time rTmax Relative time to the maximum of residue function sICAS Symptomatic intracranial atherosclerotic stenosis OR, odds ratio; CI, confidence interval. *Model 1: multivariable binary logistic regression model adjusted for age, NIHSS score at admission, and stenosis degree of the sICAS lesion. †Model 2: model 1 further adjusting for the onset to CTP time period.