The burden of intracranial atherosclerosis on cerebral small vessel disease: A community cohort study

Objective: Exploring the prevalence and association between intracranial atherosclerosis (ICAS) and cerebral small vessel diseases (CSVD), this study delved beyond the current scope, utilising high-resolution vessel wall MRI (HRVW-MRI) to investigate how subtle changes in intracranial atherosclerotic features influence the various burdens of CSVD.

Methods: Stroke-free Chinese adult participants were recruited from our ongoing community-based MRI cohort. HRVW-MRI technique with a T1-weighted 3D SPACE sequence was used to assess atherosclerotic plaque features: plaque load, degree of stenosis, remodelling index, eccentricity. A multi-sequence MRI assessment elucidated CSVD markers, including white matter hyperintensities, lacune infarcts, microbleeds and enlarged perivascular spaces. Statistical analyses, including sensitivity and specificity tests, chi-square, correlation and regression models were fitted to explore the association between ICAS and CSVD.

Results: Of the 225 participants (mean age 64.90 ± 6.87 years) included in the study, 101 (45%) were males. Thirty-nine participants (17.3%) presented with ICAS (8 progressive plaques and 31 were pre-atherosclerotic). One hundred and six (47.1%) participants recorded at least one clinically significant marker of CSVD. The subtle changes (increment or decrement) in atherosclerotic features such as positive remodelling, plaque load, eccentricity, degree of stenosis and the morphology (ICAS severity) may parallelly influence the distinct markers and overall CSVD burden.

Interpretation: This study demonstrates that the association between ICAS and CVSD extends beyond mere co-existence due to shared risk factors, suggesting the presence of a dose-effect relationship between ICAS and CVSD. HRVW-MRI could elucidate diagnostic metrics and characteristic features that reveal how ICAS impacts distinct CSVD burdens, thereby enhancing clinical decisions.