Lesion Patterns and Stroke Mechanism in Atherosclerotic Middle Cerebral Artery Disease

Abstract

Background and Purpose-Patterns and mechanisms of stroke in patients with atherosclerotic middle cerebral artery (MCA) disease remain unclear. We sought to identify lesion patterns and stroke mechanisms associated with MCA disease using early diffusion-weighted imaging (DWI). Methods-We reviewed 185 acute ischemic stroke patients who had (1) symptomatic lesions located in the unilateral MCA territory on DWI performed within 48 hours of symptom onset, and (2) either corresponding MCA disease, internal carotid artery disease, or cardioembolism. Acute DWI lesion patterns were classified as (1) single (small perforator Ͻ2 cm; large perforator Ն2 cm; pial; large territorial; border-zone) and (2) multiple. Results-MCA disease was diagnosed in 63 patients, 32 (50.8%) of whom showed multiple lesions. Concomitant perforator and pial infarcts (14/63, PϽ0.001), concomitant perforator, pial, and border-zone infarcts (9/63, PϽ0.001), and single small perforator infarcts (12/63, Pϭ0.001) were identified more often in patients with MCA disease than in those with cardioembolism or internal carotid artery disease. Small perforator infarcts were more common in patients with milder stenosis than with severe stenosis or occlusion of MCA (PϽ0.001). Whether they occurred singly or in addition to other lesions, pial infarcts were identified more often in patients with severe stenosis or occlusion of MCA (Pϭ0.001). Conclusions-Perforating artery infarcts, whether single or occurring in addition to pial or border-zone infarcts, are lesion patterns specific for MCA disease. This suggests that local branch occlusion and coexisting distal embolization may be a common stroke mechanism in patients with MCA disease.

Multidetector computed tomography angiography in clinically suspected hyperacute ischemic stroke in the anterior circulation: an etiological workup in a cohort of Brazilian patients

“…The intracranial cerebrovascular system was scrutinized to be interpreted according to current literature 11,16,17 . A diagnosis of atherothrombosis was assumed when relevant cervical artery atherosclerosis was concomitant with a MCA thrombus.…”

Penetrating arterioles are a bottleneck in the perfusion of neocortex

“…3) suggests that lesions to the penetrating arteries are an important mechanism in cerebrovascular disease in humans. Recent work indicates that microstrokes that are completely or largely confined to the gray matter (28)(29)(30), along with small pial infarcts after certain strokes (31), have clinical consequences. We suggest that progress in treatment of small strokes will benefit from animal models of small stroke that target penetrating arterioles.…”

Simultaneous Bilateral Carotid Stenting in High-Risk Patients

“…Diffusion-weighted MR images obtained in 22 patients with bilateral lesions revealed new ischemic lesions in 16 patients-that is, borderzone (n ϭ 8), wedgeshaped pial (n ϭ 5), and scattered superficial cortical (n ϭ 3) lesion patterns of acute ischemic change. 20 Nineteen (63%) among the 30 patients with bilateral lesions had 1 symptomatic side based on the presenting symptoms and/or lesions seen on MR imaging. Two patients were regarded as having bilateral symptoms: One presented with symptoms related to the contralateral side within a 1-week interval, and the other presented with bilateral acute ischemic lesions on both sides of the middle cerebral artery territories on diffusion-weighted imaging.…”