Temporal evolution of vessel wall abnormalities in young ischemic stroke – the ODYSSEY study

INTRODUCTION: We examined the temporal patterns of vessel wall (VW) lesions on high-resolution MRI (HR-MRI) in a cohort of young stroke survivors. STUDY AND METHODS: This substudy of the ODYSSEY is a single-center prospective cohort study comprising participants aged 18-50, who experienced imaging proven cerebral stroke and underwent HR-MRI at baseline and after two years. These scans were independently reviewed by two neuroradiologists blinded to clinical information. We studied determinants of vessel wall lesions and association with recurrent ischemic events. RESULTS: 75 participants (median age: 40.5 years (32.1-46.2) and 45% was female) were included. Time between the HR-MRIs was 2.0 years (IQR 1.8-2.2). At baseline, 16 (21.3%) participants exhibited 35 VW lesions, mainly VW enhancement (VWE) (60%). During follow-up, eleven participants (15%) exhibited 22 lesions, mostly VWE (91%), comprising eleven persistent baseline lesions, eleven newly developed lesions, and 69% baseline lesions resolved. Persisting and new lesions were more frequently found in patients with dyslipidemia at baseline (p=0.03, both). Stroke etiology was not associated with temporal patterns. Ten participants developed new ischemia with three being symptomatic. One of these symptomatic participants showed resolved VWE in the corresponding vascular territory The presence of VW lesions at follow-up was not associated with a statistically significant increased risk of cerebral ischemic recurrence or with incident ischemia on MRI at follow-up. DISCUSSION: This study underscores the dynamic nature of VW lesions in young stroke survivors. Baseline lesions frequently resolved, while new ones appeared during follow-up, with underlying mechanisms and implications yet to be fully understood. Further research is needed to determine their clinical significance.