Isolated MCA Disease in Patients Without Significant Atherosclerotic Risk Factors

Abstract

Background and Purpose-Diagnosis of intracranial artery atherosclerosis remains often uncertain. The high-resolution magnetic resonance imaging (HR-MRI) enables vessel wall assessment for more precise diagnoses. The aim of the present study was to investigate the etiologies of middle cerebral artery steno-occlusive disease in young adult patients with few atherosclerotic risk factors using HR-MRI. Methods-We prospectively studied patients who visited a tertiary hospital in Seoul, Korea, and had (1) unilateral middle cerebral artery disease (≥50% stenosis or occlusion), (2) were ≤55 years old and had no or minimal (≤1) atherosclerotic risk factors. We excluded patients with a confirmed diagnosis of Moyamoya disease, vasculitis, or dissection and those having emboligenic sources. A presumptive diagnosis was made based on HR-MRI findings, and patients were categorized as HR-athero (atherosclerotic disease), HR-MMD (Moyamoya disease), HR-dissection, or HR-vasculitis. Results-Among 95 patients analyzed, 26 (27.4%) had HR-athero who were more often male (P=0.004), smokers (P=0.018), and had focal stenosis (P=0.003) than others. As compared with the HR-athero patients, 29 HR-MMD patients were more often female (P<0.001) and more often had occlusive lesions (P=0.001) and nonfocal stenosis (P<0.001). The 22 HRdissection patients tended to have hypertension less often, and the 13 HR-vasculitis patients were younger (P=0.004) and tended to have nonfocal stenosis. Conclusions-In our cohort of young patients with minimal risk factors, atherosclerosis seems to be an uncommon pathology of middle cerebral artery stenosis. HR-MRI aids us to make a more reliable diagnosis.

Etiology of intracranial stenosis in young patients: a high-resolution magnetic resonance imaging study

“…Although intracranial concentric wall lesions can be seen in patients with atherosclerosis, they were more frequently reported infective or non-infective vasculitis, and other vasculopathy (3,8,23,24). In this study, 19.7% patients had concentric wall lesions.…”

“…In a multinational cohort study in Europe, intracranial atherosclerotic stenosis and occlusions (11.8%) were more prevalent than extracranial carotid artery disease (8.9%) in patients ≤55 years old with ischemic stroke and transient ischemic attacks (26). In another single-center cohort study in South Korea, using HRMRI, intracranial atherosclerosis was diagnosed in 27.4% patients aged ≤55 years old with unilateral MCA stenosis and with no or minimal (≤1) atherosclerotic risk factors (24). Comparatively, the strength of current study was that the patient recruitment was based on the presence of intracranial artery stenosis, regardless of clinical background (atherosclerosis risk factors and ischemic events).…”

Clinical interpretation of high-resolution vessel wall MRI of intracranial arterial diseases

“…The length of involvement is variable, but often focal. 2 In the setting of acute atherosclerotic embolic infarct, the walls of the arteries just proximal to the infarcts often demonstrate circumferential enhancement, resulting in a multifocal appearance that could be confused with vasculitis. 3 In addition, an intraluminal thrombus itself can enhance and wall enhancement just proximal to the site of embolism may be present ( Figure 3).…”

“…In some cases, MMD can be unilateral. 2 Involvement of the entire M1 segment can occur. Early MMD does not always demonstrate the classic basal "puff of smoke" collateralization and may not be distinguishable from other causes of steno-occlusive disease on luminal evaluation.…”

Intracranial vessel wall MRI: a review of current indications and future applications

“…An example of how clinical information would help inform the utility of IVWM would be moyamoya disease, which would be expected to be more common in Asian patients with few vascular risk factors [108]. Angiographic imaging findings of moyamoya disease have been described as severely narrowed or occluded arteries of the proximal anterior circulation with extensive collateralization.…”