Purpose: Even after comprehensive evaluations, the etiology of 25-39% ischemic stroke remains unknown, and such a stroke often labeled as cryptogenic. Herein, we report a young patient with "cryptogenic stroke" caused by an intracranial atheroma, which was only visible on high-resolution magnetic resonance imaging (HR-MRI).
Case report: A 22-year-old male presented with acute right limb weakness. He was a smoker and had been in good health without hypertension, diabetes, hyperlipidemia or cardiac diseases. Diffusionweighted imaging revealed ischemic lesions at left basal ganglia and left centrum semiovale. Magnetic resonance angiography (MRA) showed left middle cerebral artery (MCA) stenosis (>50%). Six days later, this stenosis disappeared on repeated MRA and digital subtraction angiography. HRMRI suggested a superior-wall atheroma at the location where the stenosis previously existed. We hypothesize heavy thrombosis formation at the surface of atheroma may have caused a stenosis, while the subsequent spontaneous fibrinolysis may gradually eliminate this thrombosis and make the stenosis invisible.
Conclusion: Intracranial non-stenotic atheroma is a potential cause of a stroke. Our observation support HR-MRI as a tool for the etiology evaluation in young patients with cryptogenic stroke.