Following the curvature: Sulcal versus gyral cortical localization of cerebral microbleeds in cerebral amyloid angiopathy.

Cerebrospinal fluid (CSF) mediated brain clearance and inflammation are known features of cerebral amyloid angiopathy (CAA), that may be affected by the cortical gyrencephalic structure. Considering these processes in the development of cerebral microbleeds (CMB), we compared sulcal and gyral cortical CMB densities in sporadic and Dutch-type hereditary CAA (sCAA and D-CAA). CMBs were annotated on 3-Tesla susceptibility weighted imaging. Sulcal and gyral cortex-maps were created using FreeSurfer's curvature analysis. Sulcal and gyral CMB densities were compared using a generalized linear mixed model. Sensitivity analyses examined sulcal versus gyral CMB densities (1) after adjusting for disease type (sCAA vs D-CAA) and (2) in participants with lobar and deep CMBs. Thirty-nine participants were included (28/11 sCAA/D-CAA, mean age 70/53 years). Sulcal CMB density was higher than gyral CMB density (B = 0.57, exp(B) = 1.76, p < 0.001, exp(B) provides the CMB density ratio(sulcal vs gyral)). Sensitivity analyses showed robustness of sulcal CMB predominance when taking disease type into account (B = 0.46, exp(B) = 1.59, p = 0.036), with higher densities in sCAA (B = 1.36, exp(B) = 3.90, p = 0.045), and when analyzing the participants with lobar and deep CMBs (B = 0.62, exp(B) = 1.86, p < 0.001). Sulcal CMB predominance in CAA may indicate varying hemorrhagic vulnerability along the cortex, potentially arising from anatomy-based inflammatory and CSF flow dynamics variations.