Lacunes, Microinfarcts and Vascular Dysfunction in Cerebral Amyloid Angiopathy.

Objective We aimed to analyze the relationship of lacunes with cortical cerebral microinfarcts (CMI), to assess their association with vascular dysfunction and to evaluate their effect on the risk of incident intracerebral hemorrhage (ICH) in cerebral amyloid angiopathy (CAA). Methods The count and topography of lacunes (deep/lobar), CMIs and white matter hyperintensity (WMH) volume were retrospectively analyzed in a prospectively enrolled CAA cohort that underwent high-resolution research MRIs. The relationship of lacunes with CMIs and other CAA-related markers including time-to-peak (TTP) of blood-oxygen-level-dependent signal-an established measure of vascular dysfunction-was evaluated in multivariate models. Adjusted Cox regression models were used to investigate the relationship between lacunes and incident ICH. Results The cohort consisted of 122 nondemented probable CAA patients (mean age, 69.4 ± 7.6 years). Lacunes were present in 31 patients (25.4%), all but one were located in lobar regions. Cortical CMIs were more common in patients with lacunes compared to patients without lacunes (51.6% vs 20.9%, p = 0.002). TTP was not associated with either lacunes or CMIs (both p > 0.2) but longer TTP response independently correlated with higher WMH volume (p = 0.001). Lacunes were associated with increased ICH risk in univariate and multivariate Cox-regression models (p = 0.048 and p = 0.026, respectively). Conclusions Our findings show a high prevalence of lobar lacunes, frequently co-existing with CMIs in CAA, suggesting that these 2 lesion types may be part of a common spectrum of CAA-related infarcts. Lacunes were not related to vascular dysfunction but predicted incident ICH, favoring severe focal vessel involvement rather than global ischemia as their mechanism.