Background: Using high-resolution magnetic resonance imaging (HRMRI), we sought to investigate the underlying etiology of intracranial stenosis in young patients.
Methods:We retrospectively studied 122 Chinese young adult patients (from 18 to 45 years old, mean age 36.2±7.5 years) with unilateral middle cerebral artery (MCA) stenosis based on a prospectively established HRMRI database. The eccentricity, degree of stenosis, and remodeling types of MCA lesions were analyzed.The MCA lesions were classified as eccentric (presumed atherosclerosis) or concentric stenosis (presumed non-atherosclerosis). The clinical data and vessel wall properties were compared between the patients >35 years old and the patients ≤35 years old.Results: Eccentric stenosis was observed in 98 (80.3%) patients and concentric stenosis in 24 (19.7%) patients. The patients with eccentric stenosis were older (37.5±6.8 vs. 31.4±8.4 years old, P<0.001) and more likely had atherosclerosis risk factors (56.1% vs. 25.0%, P=0.006). The patients >35 years old had higher prevalence (90.1% vs. 66.7%, P=0.001) of eccentric stenosis and atherosclerosis factors (60.6% vs. 35.3%, P=0.006) than the patients ≤35 years old. Most of the patients with concentric stenosis were ≤35 years old (17/24, 70.8%) and were female (16/24, 66.7%). Binary Logistic analysis suggested smoking (OR =3.171; 95% CI,) and remodeling ratio (OR =1.625; 95% CI, 1.001-2.636) were independent predictive factors for symptomatic stenosis.Conclusions: Atherosclerosis is the most common cause of intracranial stenosis in Chinese young patients.Non-atherosclerosis disease is an important etiology in young female, especially in the patients aged 35 years old or younger.