Background:
Using High-resolution magnetic resonance imaging(HRMRI), we aimed to investigate the etiology of intracranial stenosis in patients younger than 35 years.
Methods:
Fifty-four consecutive patients (mean age,29±6 years) with middle cerebral artery stenosis were evaluated by HRMRI. The morphology of artery lesions and clinical data were analyzed. Probable atherosclerotic plaques were diagnosed by the presence of eccentric wall thickening. Probable non-atherosclerotic lesions were diagnosed by the presence of concentric wall thickening and absence of plaques.On quantitative analysis, when constrictive remodeling can be identified by visual inspection, vessel shrinkage was defined.
Results:
Plaques were found in 32 (59%) patients, including 13 patients without any atherosclerosis risk factors. The patients with a plaque tended to be older (p=0.061), male (p=0.013), and more likely have atherosclerosis risk factors(59% vs. 23%, p=0.012), expansive artery remodeling (37.5% vs. 0,p<0.001), and infarctions (75% vs. 45%, p=0.044). The non-atherosclerotic lesions more often displayed vessel shrinkage (100% vs. 31%, p<0.001) and concentric wall enhancement (83% vs.13%, p<0.001).
Conclusion:
In this study, atherosclerosis accounted for a high percentage of intracranial artery stenosis in patients younger than 35 years when HRMRI was introduced into the diagnostic setting. Intracranial non-atherosclerotic stenosis has distinct vascular pathophysiology from atherosclerotic stenosis and is often free from stroke.
Noninvasive In Vivo High-Resolution Magnetic Resonance Imaging of Atherosclerotic Lesions in Genetically Engineered Mice