Arterial wall shear stress (WSS) contributes to atherosclerosis from its inception, progression, and disruption of plaque. However, there is no previous study for an association between cerebral artery WSS and clinical outcome in patients with ischemic stroke in lenticulostriate artery.

The researchers aimed to investigate whether the signal intensity gradient (SIG) from Time-of-Flight Magnetic Resonance Angiography (TOF MRA) in cerebral arteries, as a surrogate measure of arterial WSS, is associated with clinical outcome, which was determined with modified Rankin Scale (mRS).

The patients (n=294) with the lenticulostriate artery infarction were collected in 3 hospitals with variable locations and sizes (Gunsan, Jeonju, and Seoul). For a clinical outcome, National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were checked serially from the date of admission. The mRS 2 or less at the 7th day or discharge was defined as a favorable outcome. The arterial SIGs were measured concurrently in both internal carotid, anterior/middle/posterior cerebral, vertebral arteries, and basilar artery from TOF MRA on initial diagnosis. The independent association between the clinical outcome and cerebral arterial SIG was analyzed adjusting for all the possible potential confounders.

Inclusion Criteria:

1. Patients aged 18 years or older who had brain magnetic resonance imaging (MRI) for acute ischemic stroke within 3 days
2. Patients who underwent diffusion-weighted imaging (DWI) and apparent diffusion coefficient of the cerebral parenchyma, and cerebral angiographic measurements, in which, intracranial arteries should be examined by time-of-flight (TOF) techniques
3. A patient with high signal intensity lesions in the unilateral LSA territory on DWI.

Exclusion Criteria:

1. Patients younger than 18 years of age
2. Patients with moderate to severe (>50%) stenosis or occlusion of the major intracranial and extracranial arteries, including internal carotid artery (ICA), middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), basilar artery (BA), and vertebral artery (VA)
3. Patients whose ischemic stroke was due to or related with cardiac or rare etiology (e.g., arterial dissection, moyamoya disease).

This study is a multi-center, retrospective cohort study for all consecutive patients. From January 2015 to March 2021, patients who were diagnosed with acute ischemic stroke in the lenticulostriate artery (LSA) territory were registered at three centers (Jeonbuk National University Hospital, Samsung Medical Center, and Gunsan Medical Center). The 3 centers have their own characteristics: Gunsan Medical center is in a small city where about 300,000 citizens live, Jeonbuk National University Hospital is in a medium sized city where about 650,000 citizens live, and Samsung Medical Center is in a capital city where about 10,000,000 citizens live).