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Background: Prion-like transmission of amyloid-ß through cadaveric dura, decades after neurosurgical procedures, has been hypothesized as an iatrogenic cause of cerebral amyloid angiopathy (CAA). We investigated new and previously described patients to assess the clinical profile, radiological features, and outcome of this presumed iatrogenic CAA-subtype (iCAA). Methods: Patients were collected from our prospective lobar hemorrhage and CAA database (n=251) with patients presenting to our hospital between 2008 and 2022. In addition, we identified patients with iCAA from 2 other Dutch CAA-expertise hospitals and performed a systematic literature-search for previously described patients. We classified patients according to the previously proposed diagnostic criteria for iCAA, assessed clinical and radiological disease features, and calculated intracerebral hemorrhage (ICH)-recurrence rates. We evaluated the spatial colocalization of cadaveric dura placement and CAA-associated magnetic resonance imaging markers. Results: We included 49 patients (74% men, mean age 43 years [range, 27–84]); 15 from our database (6% [95% CI, 3%–10%]; 45% of patients Conclusions: iCAA seems common in patients presenting with nonhereditary CAA under the age of 55. Clinical and radiological features are comparable with sCAA. After diagnosis, multiple ICH-recurrences but also long symptom-free intervals can occur. Harmonized registries are necessary to identify and understand this potentially underrecognized CAA-subtype.

Background: Whether certain activities can trigger spontaneous intracerebral hemorrhage (ICH) remains unknown. Insights into factors that trigger vessel rupture resulting in ICH improves knowledge on the pathophysiology of ICH. We assessed potential trigger factors and their risk for ICH onset. Methods: We included consecutive patients diagnosed with ICH between July 1, 2013, and December 31, 2019. We interviewed patients on their exposure to 12 potential trigger factors (eg, Valsalva maneuvers) in the (hazard) period soon before onset of ICH and their normal exposure to these trigger factors in the year before the ICH. We used the case-crossover design to calculate relative risks (RR) for potential trigger factors. Results: We interviewed 149 patients (mean age 64, 66% male) with ICH. Sixty-seven (45%) had a lobar hemorrhage, 60 (40%) had a deep hemorrhage, 19 (13%) had a cerebellar hemorrhage, and 3 (2%) had an intraventricular hemorrhage. For ICH in general, there was an increased risk within an hour after caffeine consumption (RR=2.5 [95% CI=1.8–3.6]), within an hour after coffee consumption alone (RR=4.8 [95% CI=3.3–6.9]), within an hour after lifting >25 kg (RR=6.6 [95% CI=2.2–19.9]), within an hour after minor head trauma (RR=10.1 [95% CI=1.7–60.2]), within an hour after sexual activity (RR=30.4 [95% CI=16.8–55.0]), within an hour after straining for defecation (RR=37.6 [95% CI=22.4–63.4]), and within an hour after vigorous exercise (RR=21.8 [95% CI=12.6–37.8]). Within 24 hours after flu-like disease or fever, the risk for ICH was also increased (RR=50.7 [95% CI=27.1–95.1]). Within an hour after Valsalva maneuvers, the RR for deep ICH was 3.5 (95% CI=1.7–6.9) and for lobar ICH the RR was 2.0 (95% CI=0.9–4.2). Conclusions: We identified one infection and several blood pressure related trigger factors for ICH onset, providing new insights into the pathophysiology of vessel rupture resulting in ICH.

Background and Purpose: Cortical calcifications have been reported in patients with cerebral amyloid angiopathy (CAA), although their prevalence and pathophysiology are unknown. We investigated the frequency of calcifications on computed tomography, their association with intracerebral hemorrhage (ICH) and their coexistence with a striped pattern of the occipital cortex reflecting microcalcifications on ultra-high-field 7T-magnetic resonance imaging in Dutch-type hereditary CAA (D-CAA) and sporadic CAA. Methods: We included D-CAA mutation carriers with a proven APP (amyloid precursor protein) mutation or ≥1 lobar ICH and ≥1 first-degree relative with D-CAA and sporadic CAA patients with probable CAA according to the modified Boston criteria. D-CAA carriers were regarded symptomatic when they had a history of symptomatic ICH. We assessed the presence, location, and progression of calcifications and their association with ICH and the striped occipital cortex. Results: We found cortical calcifications in 15/81 (19% [95% CI, 11–29]) D-CAA mutation carriers (15/69 symptomatic and 0/12 presymptomatic) and in 1/59 (2% [95% CI, 0–9]) sporadic CAA patients. Calcifications were all bilateral located in the occipital lobes. In 3/15 (20%) of the symptomatic D-CAA patients the calcifications progressed over a period up to 10 years. There was evidence of an association between cortical calcifications and new ICH development (hazard ratio, 7.1 [95% CI, 0.9–54.9], log-rank P =0.03). In 7/25 D-CAA symptomatic carriers in whom a 7T-magnetic resonance imaging was performed, a striped pattern of the occipital cortex was present; in 3/3 (100%) of those with calcifications on computed tomography and 4/22 (18%) of those without calcifications. Conclusions: Occipital cortical calcifications are frequent in D-CAA but seem to be rare in sporadic CAA. Their absence in presymptomatic carriers and their association with ICH might suggest that they are a marker for advanced CAA. Cortical calcifications on computed tomography seem to be associated with the striped occipital cortex on 7T-magnetic resonance imaging which may possibly represent an early stage of calcification.

Background and Purpose: The Edinburgh computed tomography and genetic criteria enable diagnosis of cerebral amyloid angiopathy (CAA) associated lobar intracerebral hemorrhage (ICH) but have not been validated in living patients. We assessed the sensitivity of the Edinburgh criteria in patients with acute lobar ICH due to Dutch-type hereditary CAA; a genetic and pure form of CAA. Methods: We retrospectively analyzed computed tomography-scans from a cohort of consecutive Dutch-type hereditary CAA patients who presented with ≥1 episode(s) of acute lobar ICH at the Leiden University Medical Center. Presence of subarachnoid hemorrhage (SAH) and finger-like projections (FLP) were determined. Association of SAH and FLP with ICH volume was analyzed using multivariate linear regression. Results: We included 55 Dutch-type hereditary CAA patients (mean age 56 years, 55% men) with a total of 107 episodes of acute lobar ICH. SAH was present in 82/107 (76%) and FLP in 62/107 (58%), resulting in a sensitivity of 76% for SAH and 58% for FLP. In 56 (52%), both markers were present. Nineteen (18%) lobar ICH showed no SAH extension or FLP. ICH volume was significantly associated with presence of SAH (median volume 4 versus 28 mL; P =0.001) and presence of FLP (median volume 7 versus 39 mL; P 81% (95% CI, 70%–92%), whereas in ICH volumes Conclusions: The computed tomography-based Edinburgh criteria seem to be a sensitive diagnostic test for CAA-associated lobar ICH, although they should be used with caution in small-sized lobar ICH.

Background and Purpose— To determine whether migraine, which has often been described as an inaugural manifestation in monogenic cerebrovascular syndromes, is associated with cerebral amyloid pathology, we assessed migraine and its correlation with magnetic resonance imaging markers in Hereditary Dutch-Type Cerebral Amyloid Angiopathy (D-CAA or Hereditary Cerebral Hemorrhage With Amyloidosis-Dutch type). Methods— All D-CAA mutation carriers who visited our clinic between 2012 and 2018 were included. Migraine was diagnosed by an interview and classified according to the International Classification of Headache Disorders . Magnetic resonance imaging scans were scored for intracerebral hemorrhage (ICH) location(s) and presence of cortical superficial siderosis. Kaplan Meier survival analysis was used for age of ICH onset in carriers with and without migraine. Correlation with ICH location(s) and cortical superficial siderosis were calculated with Poisson regression analysis adjusted for confounders. Results— We included 86 D-CAA mutation carriers (57% women, mean age 57 years), 48 (56%) suffered from migraine, all with aura. Prevalence was higher than expected compared with the general population (women, P P Conclusions— Migraine with aura is an important, often inaugural, symptom in D-CAA. Aura attacks lasting ≥60 minutes may signal acute ICH in D-CAA. Migraine with aura may be regarded as an early marker of disease in hereditary CAA preceding the occurrence of symptomatic ICH by several years.

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.

Disruption of the blood–brain barrier (BBB) might play a role in the pathophysiology of cerebral small vessel disease-related ICH. The aim of this study was to assess presence and extent of contrast agent leakage distant from the hematoma as a marker of BBB disruption in patients with spontaneous ICH. We prospectively performed 7 tesla MRI in adult patients with spontaneous ICH and assessed contrast leakage distant from the hematoma on 3D FLAIR images. Thirty-one patients were included (mean age 60 years, 29% women). Median time between ICH and MRI was 20 days (IQR 9–67 days). Seventeen patients (54%; seven lobar, nine deep, one infratentorial ICH) had contrast leakage, located cortical in 16 and cortical and deep in one patient. Patients with contrast leakage more often had lobar cerebral microbleeds (CMBs; 77%) than those without (36%; RR 2.5, 95% CI 1.1–5.7) and a higher number of lobar CMBs (patients with contrast leakage: median 2, IQR 1–8 versus those without: median 0, IQR 0–2; p = 0.02). This study shows that contrast leakage distant from the hematoma is common in days to weeks after spontaneous ICH. It is located predominantly cortical and related to lobar CMBs and therefore possibly to cerebral amyloid angiopathy.

Background and Purpose— The aim of the present study is to explore whether using 7 Tesla magnetic resonance imaging, additional brain changes can be observed in hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) patients as compared with the established magnetic resonance imaging features of sporadic cerebral amyloid angiopathy. Methods— The local institutional review board approved this prospective cohort study. In all cases, informed consent was obtained. This prospective parallel cohort study was conducted between 2012 and 2014. We performed T 2 *-weighted magnetic resonance imaging performed at 7 Tesla in presymptomatic mutation carriers (n=11, mean age 35±12 years), symptomatic HCHWA-D patients (n=15, mean age 45±14 years), and in control subjects (n=29, mean age 45±14 years). Images were analyzed for the presence of changes that have not been reported before in sporadic cerebral amyloid angiopathy and HCHWA-D. Innovative observations comprised intragyral hemorrhaging and cortical changes. The presence of these changes was systematically assessed in all participants of the study. Results— Symptomatic HCHWA-D-patients had a higher incidence of intragyral hemorrhage (47% [7/15], controls 0% [0/29], P P Conclusions— The presence of cortical changes and intragyral hemorrhage are imaging features of HCHWA-D that may help recognizing sporadic cerebral amyloid angiopathy in living patients.

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.

Objective:To investigate CSF biomarkers in presymptomatic and symptomatic mutation carriers with hereditary cerebral hemorrhage with amyloidosis–Dutch type (HCHWA-D), a model for sporadic cerebral amyloid angiopathy, and to determine the earliest deposited form of β-amyloid (Aβ).Methods:HCHWA-D mutation carriers and controls were enrolled in the cross-sectional EDAN (Early Diagnosis of Amyloid Angiopathy Network) study. The HCHWA-D group was divided into symptomatic carriers with a previous intracerebral hemorrhage and presymptomatic carriers. CSF concentrations of Aβ40, Aβ42, total tau, and phosphorylated tau181 proteins were compared to those of controls of a similar age. Correlations between CSF biomarkers, MRI markers, and age were investigated with multivariate linear regression analyses.Results:We included 10 symptomatic patients with HCHWA-D (mean age 55 ± 6 years), 5 presymptomatic HCHWA-D carriers (mean age 36 ± 13 years), 31 controls 40 and Aβ42 were significantly decreased in symptomatic carriers vs controls (median Aβ40 1,386 vs 3,867 ng/L, p < 0.001; median Aβ42 289 vs 839 ng/L, p < 0.001) and in presymptomatic carriers vs controls (median Aβ40 3,501 vs 4,684 ng/L, p = 0.011; median Aβ42 581 vs 1,058 ng/L, p < 0.001). Among mutation carriers, decreasing CSF Aβ40 was associated with higher lobar microbleed count (p = 0.010), increasing white matter hyperintensity volume (p = 0.008), and presence of cortical superficial siderosis (p = 0.02).Conclusions:Decreased levels of CSF Aβ40 and Aβ42 occur before HCHWA-D mutation carriers develop clinical symptoms, implicating vascular deposition of both Aβ species as early steps in cerebral amyloid angiopathy pathogenesis. CSF Aβ40 and Aβ42 may serve as preclinical biomarkers of cerebral amyloid angiopathy pathology.

Objective We hypothesized that vascular amyloid contributes to chronic brain ischemia, therefore amyloid burden measured by Pittsburgh compound B retention on positron emission tomography (PiB PET) would correlate with the extent of magnetic resonance imaging (MRI) white matter hyperintensities (WMH; or leukoaraiosis) in patients with high vascular amyloid deposition (cerebral amyloid angiopathy [CAA]) but not in patients with high parenchymal amyloid deposition (Alzheimer disease [AD]; mild cognitive impairment [MCI]) or in healthy elderly (HE) subjects. Methods Forty-two nondemented CAA patients, 50 HE subjects, and 43 AD/MCI patients had brain MRI and PiB PET. Multivariate linear regression was used to assess the independent association between PiB retention and white matter disease volume, controlling for age, gender, apolipoprotein E genotype, and vascular risk factors within each group. Results CAA patients were younger than HE and AD subjects (68 ± 10 vs 73.3 ± 7 and 74 ± 7.4, p < 0.01) but had higher amounts of WMH (median = 21 vs 3.2 and 10.8 ml, respectively, p < 0.05 for both comparisons). Global PiB retention and WMH showed strong correlation (rho = 0.52, p < 0.001) in the CAA group but not in HE or AD. These associations did not change in the multivariate models. Lobar microbleed count, another marker of CAA severity, also remained as an independent predictor of WMH volume. Interpretation Our results indicate that amyloid burden in CAA subjects (with primarily vascular amyloid) but not AD subjects (with primarily parenchymal amyloid) independently correlates with WMH volume. These findings support the idea that vascular amyloid burden directly contributes to chronic cerebral ischemia and highlights the possible utility of amyloid imaging as a marker of CAA severity. Ann Neurol 2013;73:529–536

Introduction An MRI-based score of total small vessel disease burden (CAA-SVD-Score) in cerebral amyloid angiopathy (CAA) has been demonstrated to correlate with severity of pathologic changes. Evidence suggests that CAA-related intracerebral hemorrhage (ICH) recurrence risk is associated with specific disease imaging manifestations rather than overall severity. We compared the correlation between the CAA-SVD-Score with the risk of recurrent CAA-related lobar ICH versus the predictive role of each of its components. Methods Consecutive patients with CAA-related ICH from a single-center prospective cohort were analyzed. Radiological markers of CAA related SVD damage were quantified and categorized according to the CAA-SVD-Score (0–6 points). Subjects were followed prospectively for recurrent symptomatic ICH. Adjusted Cox proportional hazards models were used to investigate associations between the CAA-SVD-Score as well as each of the individual MRI signatures of CAA and the risk of recurrent ICH. Results In 229 CAA patients with ICH, a total of 56 recurrent ICH events occurred during a median follow-up of 2.8 years [IQR 0.9–5.4 years, 781 person-years). Higher CAA-SVD-Score (HR = 1.26 per additional point, 95%CI [1.04–1.52], p = 0.015) and older age were independently associated with higher ICH recurrence risk. Analysis of individual markers of CAA showed that CAA-SVD-Score findings were due to the independent effect of disseminated superficial siderosis (HR for disseminated cSS vs none: 2.89, 95%CI [1.47–5.5], p = 0.002) and high degree of perivascular spaces enlargement (RR = 3.50–95%CI [1.04–21], p = 0.042). Conclusion In lobar CAA-ICH patients, higher CAA-SVD-Score does predict recurrent ICH. Amongst individual elements of the score, superficial siderosis and dilated perivascular spaces are the only markers independently associated with ICH recurrence, contributing to the evidence for distinct CAA phenotypes singled out by neuro-imaging manifestations.

Background The association between cerebral small vessel diseases (cSVD) and intracranial atherosclerosis is debated and conflicting results have been reported. We sought to investigate this association in patients with intracerebral hemorrhage (ICH), due to severe cSVD. Methods Consecutive ICH patients were divided into those meeting criteria for cerebral amyloid angiopathy (CAA) and those with deep hypertensive ICH consistent with hypertensive cSVD (HTN-SVD). White matter hyperintensity volumes (WMH) and microbleed counts (MB) were measured on MRI. CTA was rated for severity of intracranial carotid calcifications and for presence of > 50% intracranial stenosis (ICS). Associations of intracranial atherosclerosis severity with type of SVD (CAA vs HTN-cSVD) and with imaging and clinical markers of cSVD burden were analyzed. Results The cohort included 253 CAA and 90 HTN-SVD patients. In multivariable models, the type of cSVD (CAA vs. HTN-cSVD) was not associated with calcification severity (OR = 1.04, 95% CI [0.62–3.5], p = 0.37) or presence of ICS (OR = 0.84, 95% CI [0.21–2.74], p = 0.78). We found no association between intracranial atherosclerosis (calcifications and stenoses) and parenchymal markers of cSVD severity (WMH and MB, adjusted p ≥ 0.2 for all comparisons) and no association with presence of dementia before ICH (adjusted p ≥ 0.2 for both comparisons). Conclusions We found no association between intracranial atherosclerosis and parenchymal or clinical consequences of cSVD, suggesting that cSVDs while sharing some risk factors are not influenced by upstream larger vessel pathologies.

Importance Cerebral amyloid angiopathy–related inflammation (CAA-ri) is an important diagnosis to reach in clinical practice because many patients with the disease respond to immunosuppressive therapy. Reliable noninvasive diagnostic criteria for CAA-ri would allow some patients to avoid the risk of brain biopsy. Objective To test the sensitivity and specificity of clinical and neuroimaging-based criteria for CAA-ri. Design, Setting, and Participants We modified the previously proposed clinicoradiological criteria and retrospectively analyzed clinical medical records and magnetic resonance imaging fluid-attenuated inversion recovery and gradient-echo scans obtained from individuals with CAA-ri and noninflammatory CAA. At 2 referral centers between October 1, 1995, and May 31, 2013, and between January 1, 2009, and December 31, 2011, participants included 17 individuals with pathologically confirmed CAA-ri and 37 control group members with pathologically confirmed noninflammatory CAA. The control group was further divided into those with past lobar intracerebral hemorrhage (ICH) (n = 21) and those with cerebral microbleeds only and no history of ICH (n = 16). The dates of our analysis were September 1, 2012, to August 31, 2015. Main Outcomes and Measures The sensitivity and specificity of prespecified criteria for probable CAA-ri (requiring asymmetric white matter hyperintensities extending to the subcortical white matter) and possible CAA-ri (not requiring the white matter hyperintensities to be asymmetric). Results The 17 patients in the CAA-ri group were a mean (SD) of 68 (8) years and 8 (47%) were women. In the CAA-ri group, 14 of 17 (82%) met the criteria for both probable and possible CAA-ri. In the control group having noninflammatory CAA with lobar ICH, 1 of 21 (5%) met the criteria for possible CAA-ri, and none met the criteria for probable CAA-ri. In the control group having noninflammatory CAA with no ICH, 11 of 16 (69%) met the criteria for possible CAA-ri, and 1 of 16 (6%) met the criteria for probable CAA-ri. These findings yielded a sensitivity and specificity of 82% and 97%, respectively, for the probable criteria and a sensitivity and specificity of 82% and 68%, respectively, for the possible criteria. Conclusions and Relevance Our data suggest that a reliable diagnosis of CAA-ri can be reached from basic clinical and magnetic resonance imaging information alone, with good sensitivity and excellent specificity.

Background: Interactions between intracranial arterial pathologies (IAP) and cerebral small vessel disease (SVD) are an increasingly debated topic. Hypothesis: We analyzed associations between the type/severity of SVD and two IAPs, the intracranial arterial calcifications (ICAC) and intracranial stenosis (ICS) in intracerebral hemorrhage (ICH) patients. Methods: Consecutive ICH patients from a prospective cohort were included. Patients were divided into those meeting Boston criteria for cerebral amyloid angiopathy (CAA) and those with strictly deep hypertensive ICH consistent with hypertensive SVD (HTN-SVD). White matter hyperintensity volume (WMH) and microbleed count (MB) were quantitatively measured on MRI as markers of SVD severity. Head CT angiography was rated for presence of ICAC and for presence of >50% intracranial arterial stenosis (ICS). Associations of IAPs with the type of SVD (CAA vs HTN) as well as imaging markers of SVD severity were analyzed in multivariate models. We also explored the association between IAPs and presence of pre-ICH dementia. Results: The cohort included 253 CAA patients and 90 HTN-SVD. CAA patients were older (73.5 vs 64.8, p0.2) and no association with presence of dementia before ICH (p>0.2). Conclusions: HTN-SVD is associated with increased ICAC in multivariate models, suggesting either shared risk factors or direct interactions between SVD and IAP. There is no association of intracranial large artery pathologies (ICAC, ICS) with parenchymal (WMH, MB) or clinical (dementia) consequences of cerebral small vessel diseases.

Introduction The Boston criteria are the basis for a noninvasive diagnosis of cerebral amyloid angiopathy (CAA) in the setting of lobar intracerebral hemorrhage (ICH). We assessed the accuracy of these criteria in individuals with lobar microbleeds (MBs) without ICH. Methods We identified individuals aged >55 years having brain magnetic resonance imaging (MRI) and pathological assessment of CAA in a single academic hospital and a community-based population (Framingham Heart Study [FHS]). We determined the positive predictive value (PPV) of the Boston criteria for CAA in both cohorts, using lobar MBs as the only hemorrhagic lesion to fulfill the criteria. Results We included 102 individuals: 55 from the hospital-based cohort and 47 from FHS (mean age at MRI 74.7 ± 8.5 and 83.4 ± 10.9 years; CAA prevalence 60% and 46.8%; cases with any lobar MB 49% and 21.3%; and cases with ≥2 strictly lobar MBs 29.1% and 8.5%, respectively). PPV of "probable CAA" (≥2 strictly lobar MBs) was 87.5% (95% confidence interval [CI], 60.4–97.8) and 25% (95% CI, 13.2–78) in hospital and general populations, respectively. Discussion Strictly lobar MBs strongly predict CAA in non-ICH individuals when found in a hospital context. However, their diagnostic accuracy in the general population appears limited.

Background and Purpose— Cerebral microinfarcts (CMI) are important contributors to vascular cognitive impairment. Magnetic resonance imaging diffusion-weighted imaging (DWI) hyperintensities have been suggested to represent acute CMI. We aim to describe a mathematical method for estimating total number of CMI based on the presence of incidental DWI lesions. Methods— We reviewed magnetic resonance imaging scans of subjects with cognitive decline, cognitively normal subjects and previously reported subjects with past intracerebral hemorrhage (ICH). Based on temporal and spatial characteristics of DWI lesions, we estimated the annual rate of CMI needed to explain the observed rate of DWI lesion detection in each group. To confirm our estimates, we performed extensive sampling for CMI in the brain of a deceased subject with past lobar ICH who found to have a DWI lesion during life. Results— Clinically silent DWI lesions were present in 13 of 343 (3.8%) cognitively impaired and 10 of 199 (5%) cognitively intact normal non-ICH patients, both lower than the incidence in the past ICH patients (23 of 178; 12.9%; P Conclusions— Detecting even a single DWI lesion suggests an annual incidence of hundreds of new CMI. The cumulative effects of these lesions may directly contribute to small-vessel–related vascular cognitive impairment.

Background: Iron accumulation has been linked to neuronal injury following cerebral ischemia. In animals, a hypointense signal on T2*-weighted (T2*-w) MRI correlated with iron deposits in remote brain regions following ischemic stroke. We aim to assess whether such signal changes are present in remote brain structures following ischemic stroke in humans. Methods: We analyzed T2*-w images of 36 patients with unilateral ischemic stroke and 36 healthy controls. Regions of interest (ROIs) consisted of the thalamus, putamen, globus pallidus, caudate nucleus and white matter. To quantify signal intensity in ROIs ipsilateral to the infarct, signal intensity was measured in the ROIs in both hemispheres and a ratio of signal intensity was calculated. Signal asymmetry was compared between patients and controls and its relation with time after stroke onset was assessed. Results: In 34 (94%) patients, the thalamus ipsilateral to the infarct was hypointense compared to the contralateral thalamus. Ipsilateral thalamic signal hypointensity was significantly different between patients and controls (p < 0.001) and was present as early as 1 day after stroke onset. In other ROIs, no difference was found between patients and controls. No association was found between intensity asymmetry and time. Conclusion: We demonstrated that, as early as days after ischemic stroke, T2*-w signal intensity was decreased in the ipsilateral thalamus. This finding might indicate pathophysiologic changes in regions outside the infarcted area, possibly reflecting toxic iron accumulation.

Introduction: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a disease subtype characterized by rapidly progressive cognitive decline, seizures, headaches, T2-hyperintense MRI lesions, and neuropathologic evidence of CAA-associated vascular inflammation. CAA-ri is an important diagnosis to reach in clinical practice, as many patients respond to immunosuppressive therapy. Definitive diagnosis of CAA-ri generally requires brain biopsy, however, highlighting the importance of developing noninvasive diagnostic criteria. Objectives: To test the sensitivity and specificity of modified criteria (Table 1) for possible and probable CAA-ri in groups of subjects with histologically proven CAA-ri and non-CAA-ri. Methods: After refining previously proposed clinical- radiological criteria we retrospectively analyzed clinical charts and MRI FLAIR and gradient-echo scans obtained from 17 subjects with pathologically confirmed CAA-ri and 37 control subjects with pathologic diagnosis of non-inflammatory CAA. The control group was further divided into those with past intracerebral hemorrhage (ICH) (n=21) and those with cerebral microbleeds (CMB) only and no history of ICH (n=16). Results: In the CAA-ri group 14/17 (82.4%) met criteria for both probable and possible CAA-ri. One (4.7%) of the subjects in the control CAA-ICH group (n=21) met the criteria for possible and none met criteria for probable CAA-ri. In the control CAA-no ICH group 1/16 (6.25%) and 11/16 (68.75%) met criteria for probable and possible CAA-ri respectively. This yields sensitivity and specificity of 82% and of 97.3% respectively for the probable criteria and sensitivity and specificity of 82% and 67.6% respectively for the possible criteria. Conclusions: Our data suggest that a reliable diagnosis of CAA-ri can be reached from basic clinical and radiographic information alone with good sensitivity and excellent specificity.

Objective: We aimed to identify the potential contributions of cerebral amyloid angiopathy (CAA) and hypertensive microvasculopathy on periventricular (PV) and subcortical (SC) white matter disease (WMD). Methods: Total, SC and PV WMD volumes of 359 CAA patients and 102 patients with hypertensive intracerebral hemorrhage (htn-ICH) were quantitatively measured on FLAIR MRI. The presence of 6 different subcortical WMD patterns (detailed under Results and Figure 1) was recorded. The independent predictors of each of these WMD variables were explored using multivariate models that included the diagnosis (CAA vs htn-ICH), age, gender, ApoE genotype, vascular risk factors, total WMD volume as well as lobar and deep microbleed (MB) counts from T2*MRI. Results: CAA patients were older (mean 74 vs 68, p Conclusions: Our results show that CAA pathology is associated with the severity of both PV and SC WMD as well as presence of severe posterior and anterior SC disease. A pattern of deep peri-basal ganglia WMD is mostly associated with hypertensive disease. Recognition of these patterns might help understand the dominant type of microvasculopathy in older individuals with WMD.

BACKGROUND/OBJECTIVES: Lobar microbleeds (LMB) are increasingly identified on brain MRI of older adults, suggesting a diagnosis of cerebral amyloid angiopathy (CAA) in the absence of intracerebral hemorrhage (ICH). Identifying the baseline characteristics and risk of future ICH of these subjects is important to understand their prognosis and safety of antithrombotic use in this setting. METHODS: Baseline characteristics (demographics, risk factors, APOE genotype), markers of CAA severity (LMB counts, white matter hyperintensity volume), and finally outcomes during a mean follow up of 4 years (incidence rate of ICH and case-fatality) were compared between 62 CAA patients without and 747 with ICH diagnosed using Boston criteria upon enrollment. The association between antithrombotic use and risk of incident ICH was explored in patients presenting with isolated LMBs after adjusting for covariates listed above. RESULTS: Female gender (52% vs. 37% p=0.023) and hypertension (67% vs. 53% p=0.025) were more common in patients presenting with ICH, other baseline characteristics did not differ. Patients presenting without ICH had more LMBs (median 10 vs. 1 p CONCLUSIONS: Patients presenting with LMBs on MRI have a clinical, genetic, and neuroimaging profile suggestive of severe CAA pathology. They have a considerable risk of incident ICH albeit lower than patients who had a prior lobar ICH. The use of warfarin increases the risk of future ICH in patients with isolated LMBs on MRI.

Importance Hematoma expansion is an important determinant of outcome in spontaneous intracerebral hemorrhage (ICH) due to small vessel disease (SVD), but the association between the severity of the underlying SVD and the extent of bleeding at the acute phase is unknown to date. Objective To investigate the association between key magnetic resonance imaging (MRI) markers of SVD (as per the Standards for Reporting Vascular Changes on Neuroimaging [STRIVE] guidelines) and hematoma volume and expansion in patients with lobar or deep ICH. Design, Setting, and Participants Analysis of data collected from 418 consecutive patients admitted with primary lobar or deep ICH to a single tertiary care medical center between January 1, 2000, and October 1, 2012. Data were analyzed on March 4, 2016. Participants were consecutive patients with computed tomographic images allowing ICH volume calculation and MRI allowing imaging markers of SVD assessment. Main Outcomes and Measures The ICH volumes at baseline and within 48 hours after symptom onset were measured in 418 patients with spontaneous ICH without anticoagulant therapy, and hematoma expansion was calculated. Cerebral microbleeds, cortical superficial siderosis, and white matter hyperintensity volume were assessed on MRI. The associations between these SVD markers and ICH volume, as well as hematoma expansion, were investigated using multivariable models. Results This study analyzed 254 patients with lobar ICH (mean [SD] age, 75 [11] years and 140 [55.1%] female) and 164 patients with deep ICH (mean [SD] age 67 [14] years and 71 [43.3%] female). The presence of cortical superficial siderosis was an independent variable associated with larger ICH volume in the lobar ICH group (odds ratio per quintile increase in final ICH volume, 1.49; 95% CI, 1.14-1.94; P = .004). In multivariable models, the absence of cerebral microbleeds was associated with larger ICH volume for both the lobar and deep ICH groups (odds ratios per quintile increase in final ICH volume, 1.41; 95% CI, 1.11-1.81; P = .006 and 1.43; 95% CI, 1.04-1.99; P = .03; respectively) and with hematoma expansion in the lobar ICH group (odds ratio, 1.70; 95% CI, 1.07-2.92; P = .04). The white matter hyperintensity volumes were not associated with either hematoma volume or expansion. Conclusions and Relevance In patients admitted with primary lobar or deep ICH to a single tertiary care medical center, the presence of cortical superficial siderosis was an independent variable associated with larger lobar ICH volume, and the absence of cerebral microbleeds was associated with larger lobar and deep ICHs. The absence of cerebral microbleeds was independently associated with more frequent hematoma expansion in patients with lobar ICH. We provide an analytical framework for future studies aimed at limiting hematoma expansion.