Objective: To assess MRI-visible enlarged perivascular spaces (EPVS) burden and different topographical patterns (in the centrum semiovale [CSO] and basal ganglia [BG]) in 2 common microangiopathies: cerebral amyloid angiopathy (CAA) and hypertensive arteriopathy (HA). Methods: Consecutive patients with spontaneous intracerebral hemorrhage (ICH) from a prospective MRI cohort were included. Small vessel disease MRI markers, including cerebral microbleeds (CMBs), cortical superficial siderosis (cSS), and white matter hyperintensities (WMH), were rated. CSO-EPVS/BG-EPVS were assessed on a validated 4-point visual rating scale (0 = no EPVS, 1 = 40 EPVS). We tested associations of predefined high-degree (score >2) CSO-EPVS and BG-EPVS with other MRI markers in multivariable logistic regression. We subsequently evaluated associations with CSO-EPVS predominance (i.e., CSO-EPVS > BG-EPVS) and BG-EPVS predominance pattern (i.e., BG-EPVS > CSO-EPVS) in adjusted multinomial logistic regression (reference group, BG-EPVS = CSO-EPVS). Results: We included 315 patients with CAA-ICH and 137 with HA-ICH. High-degree CSO-EPVS prevalence was greater in CAA-related ICH vs HA-related ICH (43.8% vs 17.5%, p < 0.001). In multivariable logistic regression, high-degree CSO-EPVS was associated with lobar CMB (odds ratio [OR] 1.33, 95% confidence interval [CI] 1.10–1.61, p = 0.003) and cSS (OR 2.08, 95% CI 1.30–3.32, p = 0.002). Deep CMBs (OR 2.85, 95% CI 1.75–4.64, p < 0.0001) and higher WMH volume (OR 1.02, 95% CI 1.01–1.04, p = 0.010) were predictors of high-degree BG-EPVS. A CSO-EPVS–predominant pattern was more common in CAA-ICH than in HA-ICH (75.9% vs 39.4%, respectively, p < 0.0001). CSO-PVS predominance was associated with lobar CMB burden and cSS, while BG-EPVS predominance was associated with HA-ICH and WMH volumes. Conclusions: Different patterns of MRI-visible EPVS provide insights into the dominant underlying microangiopathy type in patients with spontaneous ICH.

The term cerebral small vessel disease (SVD) refers to a group of pathologic processes with various etiologies that affect small arteries, arterioles, venules, and capillaries of the brain. Magnetic resonance imaging (MRI) correlates of SVD are lacunes, recent small subcortical infarcts, white-matter hyperintensities, enlarged perivascular spaces, microbleeds, and brain atrophy. Endothelial dysfunction is thought to have a role in the mechanisms leading to SVD-related brain changes, and the study of endothelial dysfunction has been proposed as an important step for a better comprehension of cerebral SVD. Among available methods to assess endothelial function in vivo, measurement of molecules of endothelial origin in peripheral blood is currently receiving selective attention. These molecules include products of endothelial cells that change when the endothelium is activated, as well as molecules that reflect endothelial damage and repair. This review examines the main molecular factors involved in both endothelial function and dysfunction, and the evidence linking endothelial dysfunction with cerebral SVD, and gives an overview of clinical studies that have investigated the possible association between endothelial circulating biomarkers and SVD-related brain changes.

Objective To assess the predominant type of cerebral small vessel disease (SVD) and recurrence risk in patients who present with a combination of lobar and deep intracerebral hemorrhage (ICH)/microbleed locations (mixed ICH). Methods Of 391 consecutive patients with primary ICH enrolled in a prospective registry, 75 (19%) had mixed ICH. Their demographics, clinical/laboratory features, and SVD neuroimaging markers were compared to those of 191 patients with probable cerebral amyloid angiopathy (CAA-ICH) and 125 with hypertensive strictly deep microbleeds and ICH (HTN-ICH). ICH recurrence and case fatality were also analyzed. Results Patients with mixed ICH showed a higher burden of vascular risk factors reflected by a higher rate of left ventricular hypertrophy, higher creatinine values, and more lacunes and severe basal ganglia (BG) enlarged perivascular spaces (EPVS) than patients with CAA-ICH (all p < 0.05). In multivariable models mixed ICH diagnosis was associated with higher creatinine levels (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.2–5.0, p = 0.010), more lacunes (OR 3.4, 95% CI 1.7–6.8), and more severe BG EPVS (OR 5.8, 95% CI 1.7–19.7) than patients with CAA-ICH. Conversely, when patients with mixed ICH were compared to patients with HTN-ICH, they were independently associated with older age (OR 1.03, 95% CI 1.02–1.1), more lacunes (OR 2.4, 95% CI 1.1–5.3), and higher microbleed count (OR 1.6, 95% CI 1.3–2.0). Among 90-day survivors, adjusted case fatality rates were similar for all 3 categories. Annual risk of ICH recurrence was 5.1% for mixed ICH, higher than for HTN-ICH but lower than for CAA-ICH (1.6% and 10.4%, respectively). Conclusions Mixed ICH, commonly seen on MRI obtained during etiologic workup, appears to be driven mostly by vascular risk factors similar to HTN-ICH but demonstrates more severe parenchymal damage and higher ICH recurrence risk.

Objective: To evaluate whether the burden of deep and lobar lacunes differs between patients with intracerebral hemorrhage (ICH) with definite/probable cerebral amyloid angiopathy (CAA) per the Boston criteria and hypertensive small vessel disease (HTN-SVD; ICH in basal ganglia, thalami, brainstem). Methods: We defined lobar and deep lacunes similar to the topographic distribution used for ICH and cerebral microbleeds (CMBs). We then compared their distribution between patients with CAA-ICH and those with strictly deep CMB and ICH (HTN-ICH). The independent associations of lacune location with the diagnosis of CAA-ICH and HTN-ICH were evaluated with multivariable models. The relationship between lobar lacunes and white matter hyperintensity (WMH) volume was evaluated by means of partial correlation analyses adjusted for age and a validated visual scale. Results: In our final cohort of 316 patients with ICH, lacunes were frequent (24.7%), with similar rates in 191 patients with CAA and 125 with HTN-ICH (23% vs 27.2%, p = 0.4). Lobar lacunes were more commonly present in CAA (20.4% vs 5.7%, p < 0.001), while deep lacunes were more frequent in HTN-ICH (15.2% vs 2.1%, p < 0.001). After correction for demographics and clinical and neuroimaging markers of SVD, lobar lacunes were associated with CAA (p = 0.003) and deep lacunes with HTN-ICH (p < 0.001). Lobar lacunes in 80% of the cases were at least in contact with WMH, and after adjustment for age, they were highly correlated to WMH volume (r = 0.42, p < 0.001). Conclusions: Lobar lacunes are associated with CAA, whereas deep lacunes are more frequent in HTN-SVD. Lobar lacunes seem to have a close relationship with WMH, suggesting a possible common origin.

Objective: In order to explore the mechanisms of cortical superficial siderosis (cSS) multifocality and its clinical implications for recurrent intracerebral hemorrhage (ICH) risk in patients with cerebral amyloid angiopathy (CAA), we used a new rating method that we developed specifically to evaluate cSS extent at spatially separated foci. Methods: Consecutive patients with CAA-related ICH according to Boston criteria from a single-center prospective cohort were analyzed. The new score that assesses cSS multifocality (total range 0–4) showed excellent interrater reliability (k = 0.87). The association of cSS with markers of CAA and acute ICH was investigated. Patients were followed prospectively for recurrent symptomatic ICH. Results: The cohort included 313 patients with CAA. Multifocal cSS prevalence was 21.1%. APOE ε2 allele prevalence was higher in patients with multifocal cSS. In probable/definite CAA, cSS multifocality was independently associated with neuroimaging markers of CAA severity, including lobar microbleeds, but not with acute ICH features, which conversely, were determinants of cSS in possible CAA. During a median follow-up of 2.6 years (interquartile range 0.9–5.1 years), the annual ICH recurrence rates per cSS scores (0–4) were 5%, 6.5%, 13.5%, 16.2%, and 26.9%, respectively. cSS multifocality (presence and spread) was the only independent predictor of increased symptomatic ICH risk (hazard ratio 3.19; 95% confidence interval 1.77–5.75; p < 0.0001). Conclusions: The multifocality of cSS correlates with disease severity in probable CAA; therefore cSS is likely to be caused by discrete hemorrhagic foci. The new cSS scoring system might be valuable for clinicians in determining annual risk of ICH recurrence.