Prevalence and outcome of young stroke patients with middle cerebral artery stenosis

BACKGROUND: Etiologies of acute ischemic stroke in young adults are heterogeneous. Middle cerebral artery (MCA) stenosis is a common finding in Asians which may be an important cause of stroke in young adults. However, studies of stroke in young Asian populations are rare. Our study was to investigate the prevalence and outcome of young stroke patients with MCA stenosis in Chinese populations. METHODS: Young patients with MCA territory infarction between January 2013 and September 2018 were retrospectively recruited. Subjects were defined as stenosis group (MCA stenosis ≥50%) and no-stenosis group (MCA stenosis<50% or no stenosis) by their MCA stenosis. For patients in stenosis group, they were categorized as uni-MCA stenosis subgroup and multiple stenosis subgroup. Demographic data, risk factors, imaging feature and complications were compared between groups. Prevalence of MCA stenosis and risk factor score (score ≥ 2 or 3) in different age groups were investigated. Modified Rankin Scale (mRS) was used for evaluating functional outcome at discharge (unfavorable outcome: 3–6). Binary logistic regression was performed to determine independent risk factors of unfavorable outcome. RESULTS: Two hundred forty-nine young stroke patients were included in our study and 110 (44.2%) patients were defined as stenosis group. 55 (50%) patients were categorized as uni-MCA stenosis subgroup and 55 (50%) were multiple stenosis subgroup. The most common traditional vascular risk factors included hypertension, hyperlipemia, smoking, hyperhomocysteinemia and alcohol consumption. Prevalence of risk factor score ≥ 2 or 3 increased with age, but not incidence of MCA stenosis. By TOAST classification, the most common etiologies were large-artery atherosclerosis (41.0%) and small vessel disease (33.7%). Compared with no-stenosis group, patients in stenosis group were more likely to have large territorial infarct, develop complications and have unfavorable outcome. No significant difference was found between patients in uni-MCA stenosis and multiple stenosis subgroups except history of stroke/TIA, risk factor score ≥ 3 and silent infarct. By logistic regression, hypertension (OR = 3.561; 95%CI, 1.494 to 8.492; p = 0.004), NIHSS scores at admission (OR = 1.438; 95%CI, 1.276 to 1.620; p = 0,000) and infarct size (p = 0.015) independently predicted unfavorable outcome. CONCLUSIONS: Forty-four point two percent young Chinese adults with MCA territory infarction had MCA stenosis. Prevalence of MCA stenosis did not increase with age. Patients with MCA stenosis had worse clinical outcome, however, only hypertension, NIHSS scores at admission and infarct size were independent predictors.