Atherothrombotic Middle Cerebral Artery Territory Infarction

Abstract

Background and Purpose-MRI has superior capabilities for the detection of cerebral infarcts compared with CT. CT was used to locate infarcts in most previous studies of atherothrombotic middle cerebral artery (MCA) territory infarcts. Thus, there was a possibility of missing concomitant small infarcts. More accurate identification of topographic lesions in MCA territory with MRI may help to establish the pathogenesis of stroke. The present study determines topographic patterns, distribution of vascular lesions, and probable mechanisms. Methods-Forty-two patients with MCA territory infarcts on routine MRI and no major cause of cardioembolism were studied with conventional angiography or MR angiography. Results-The topographic patterns seen on MRI were subdivided into 4 groups: cortical border-zone infarcts (nϭ6), pial territory infarcts without insular infarct (nϭ3), pial territory infarcts with insular infarct (nϭ14), and large subcortical infarcts (nϭ19). Of 6 patients with cortical border-zone infarcts, 4 had concomitant small cortical or subcortical multiple lesions. Angiography showed intrinsic MCA disease in 4 patients. Of 3 patients with pial territory infarcts without insular infarct, 2 also had small multiple centrum ovale lesions. All had intrinsic MCA disease. Pial territory infarcts with partial or whole insular lesions were present in 10 and 4 patients, respectively. Five patients had additional multiple cortical or subcortical lesions. Ten patients had intrinsic MCA disease. Of the 19 patients with large subcortical infarcts, 12 had centrum ovale infarcts, and 4 had both basal ganglia and centrum ovale lesions. Ten had concomitant small cortical or subcortical lesions. Six patients had intrinsic MCA disease. Conclusions-Similar vascular lesions induce different topographic patterns in MCA territory infarction, which are related to individual vascular variability, degree of primary and secondary collateralization, and pathogenesis of infarcts. Our study indicates that concomitant small cortical or subcortical lesions are also commonly associated findings in diverse patterns of MCA territory infarction, which can mostly be explained by probable embolic mechanism. Key Words: angiography, magnetic resonance Ⅲ cerebral embolism Ⅲ magnetic resonance imaging Ⅲ middle cerebral artery M ost middle cerebral artery (MCA) territory infarcts have been attributed to embolism from the heart or internal carotid artery (ICA), poor perfusion due to ICA occlusion, intrinsic MCA occlusive disease, or intrinsic disease in the lenticulostriate penetrating vessels.Previous studies 1,2 indicated racial differences in atherothrombotic occlusive diseases of the anterior cerebral circulation. Specifically, extracranial atherosclerosis is more common in whites, whereas intracranial atherosclerosis is more frequent in blacks, Chinese, and Japanese. However, how the common intracranial atherosclerotic vascular lesions are associated with topographic patterns of infarcts has not been studied sufficiently.MRI of the brain has supe...

Aphasia following Striatocapsular Infarction May Be Explained by Concomitant Small Cortical Infarct on Diffusion-Weighted Imaging

“…Previous studies indicated that extracranial atherosclerosis is more common in the white population, whereas intracranial atherosclerosis is more frequent in the Black and Asian populations [26, 27]. Another report that intracranial large artery disease was observed in 71% of patients suffering from MCA infarcts in Korea supports the association between SCI and large artery disease as stroke mechanism suggested in our study [28]. In our study, the presence of aphasia in patients with SCI was found to be an excellent predictor of cortical ischemic lesions on DWI, but only a weak predictor of ipsilateral large artery disease, also in the case of MCA and ICA disease associated with a possible hemodynamic cause.…”

Long-Term Prognosis of Patients with Large Subcortical Infarctions

“…Patients with large subcortical infarcts reportedly show cardiogenic sources in 9–52% of cases [5,9,10,11,12,13,14] and stenosis of major arteries in 27–89.5% of cases [2, 5,9,10,11,12,13,14,15,16]. We stress that a cardiac source or stenosis of major arteries can cause a LSCI.…”

Paracentral Strip Infarcts of the Middle Cerebral Artery: Borderzone Ischaemia or Cortical Artery Occlusion?

“…While a number of investigators have described MCA territory small cortical or pial territory infarcts with variable topographical patterns [22, 23], we noticed a number of cases in which a thin strip-like infarct was present within the interdivisional region of the MCA territory involving cortex and sometimes extending medially to the periventricular zone. Since the topography of these infarcts appeared to be quite stereotypic, there were a number of questions which we wished to explore.…”

“…In the study by Bang et al [23], in which MR/DWI lesion topography was linked to prognosis, their subgroup ‘other cortical infarcts’ most likely contained several cases although the illustrated cases were not typical of ours in that they were larger and wedge shaped in keeping with their presumed embolic aetiology. Min et al [22] correlated DWI infarct patterns with arterial lesions. Their ‘pial territory infarcts without insular infarct’ also may have contained some cases of strip infarction, although those illustrated were wedge-shaped, multiple, centrum ovale infarcts and sometimes near external borderzones.…”

“…While the aetiology of anterior choroidal artery territory infarcts is less certain, in situ disease and embolism from a more proximal source most likely play their part [15]. More superficially, infarcts are recognised in the anterior, posterior and MCA territories and are more commonly due to embolism [16,17,18,19,20,21,22,23]. Also, in the external borderzones between MCA and anterior and posterior cerebral artery territories, haemodynamic mechanisms are thought to predominate, although this is controversial [10, 24].…”