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Background: Hemorrhagic and ischemic magnetic resonance imaging lesions as well as the more recently described decrease in vasomotor reactivity have been suggested as possible biomarkers for cerebral amyloid angiopathy (CAA). Analyses of these markers have been primarily cross-sectional during the symptomatic phase of the disease, with little data on their longitudinal progression, particularly in the presymptomatic phase of the disease when it may be most responsive to treatment. We used the unique opportunity provided by studying Dutch-type hereditary cerebral amyloid angiopathy (D-CAA) to determine longitudinal progression of CAA biomarkers during the presymptomatic as well as the symptomatic phase of the disease. Methods: In this longitudinal case-control study, magnetic resonance imaging markers and cognitive performance were assessed at baseline and after ≈4 years in 10 presymptomatic and 6 symptomatic D-CAA mutation carriers and 20 control subjects. These magnetic resonance imaging markers included hemorrhagic and ischemic manifestations, measurements of cerebral blood flow, and vasomotor reactivity to visual stimulation. Results: In presymptomatic D-CAA mutations carriers, vasomotor reactivity showed a decline over time for blood-oxygen-level–dependent amplitude ( P =0.011) and prolongation of time to peak ( P P =0.007). Conclusions: Our findings indicate that in the presymptomatic phase of D-CAA, cerebrovascular reactivity measured by the blood-oxygen-level–dependent amplitude and time to peak to visual stimulation progressively worsens and can thus be regarded as a disease progression marker. In the symptomatic phase, the most salient marker of progression appears to be recurrent intracerebral hemorrhage.

Background Recent studies suggest that superficially located cerebellar intracerebral hemorrhage (ICH) and microbleeds might point towards sporadic cerebral amyloid angiopathy (CAA). Aims We investigated the proportion of cerebellar ICH and asymptomatic macro- and microbleeds in Dutch-type hereditary CAA (D-CAA), a severe and essentially pure form of CAA. Methods Symptomatic patients with D-CAA (defined as ≥1 symptomatic ICH) and presymptomatic D-CAA mutation-carriers were included. We assessed magnetic resonance imaging scans for symptomatic (cerebellar) ICH and asymptomatic cerebellar macro- and microbleeds according to the STRIVE-criteria. Location was assessed as superficial-cerebellar (cortex, vermis or juxta-cortical) or deep-cerebellar (white matter, pedunculi cerebelli and gray nuclei). Results We included 63 participants (mean age 58 years, 60% women, 42 symptomatic). In total, the 42 symptomatic patients with D-CAA had 107 symptomatic ICH (range 1–7). None of these ICH were located in the cerebellum. Six of 42 (14%, 95%CI 4–25%) symptomatic patients and none of the 21 (0%, 95%CI 0–0%) presymptomatic carriers had ≥ 1 asymptomatic cerebellar macrobleed(s). All macrobleeds were superficially located. Cerebellar microbleeds were found in 40 of 63 (64%, 95%CI 52–76) participants (median 1.0, range 0–159), 81% in symptomatic patients and 29% in presymptomatic carriers. All microbleeds were strictly or predominantly superficially (ratio superficial versus deep 15:1) located. Conclusions Superficially located asymptomatic cerebellar macrobleeds and microbleeds are common in D-CAA. Cerebellar microbleeds are already present in the presymptomatic stage. Despite the high frequency of cerebellar micro and macrobleeds, CAA pathology did not result in symptomatic cerebellar ICH in patients with D-CAA.

Background: Deep medullary vein (DMV) changes occur in cerebral small vessel diseases (SVD) and in Alzheimer’s disease. Cerebral amyloid angiopathy (CAA) is a common SVD that has a high co-morbidity with Alzheimer’s disease. So far, DMVs have not been evaluated in CAA. Objective: To evaluate DMVs in Dutch-type hereditary CAA (D-CAA) mutation carriers and controls, in relation to MRI markers associated with D-CAA. Methods: Quantitative DMV parameters length, tortuosity, inhomogeneity, and density were quantified on 7 Tesla 3D susceptibility weighted MRI in pre-symptomatic D-CAA mutation carriers (n = 8), symptomatic D-CAA mutation carriers (n = 8), and controls (n = 25). Hemorrhagic MRI markers (cerebral microbleeds, intracerebral hemorrhages, cortical superficial siderosis, convexity subarachnoid hemorrhage), non-hemorrhagic MRI markers (white matter hyperintensities, enlarged perivascular spaces, lacunar infarcts, cortical microinfarcts), cortical grey matter perfusion, and diffusion tensor imaging parameters were assessed in D-CAA mutation carriers. Univariate general linear analysis was used to determine associations between DMV parameters and MRI markers. Results: Quantitative DMV parameters length, tortuosity, inhomogeneity, and density did not differ between pre-symptomatic D-CAA mutation carriers, symptomatic D-CAA mutation carriers, and controls. No associations were found between DMV parameters and MRI markers associated with D-CAA. Conclusion: This study indicates that vascular amyloid-β deposition does not affect DMV parameters. In patients with CAA, DMVs do not seem to play a role in the pathogenesis of MRI markers associated with CAA.

Objective To determine whether amyloid imaging with the positron emission tomography (PET) agent Pittsburgh compound B (PiB) can detect vascular β‐amyloid (Aβ) in the essentially pure form of cerebral amyloid angiopathy associated with the Dutch‐type hereditary cerebral amyloid angiopathy (D‐CAA) mutation. Methods PiB retention in a cortical composite of frontal, lateral, and retrosplenial regions (FLR) was measured by PiB‐PET in 19 D‐CAA mutation carriers (M+; 13 without neurologic symptoms, 6 with prior lobar intracerebral hemorrhage) and 17 mutation noncarriers (M−). Progression of PiB retention was analyzed in a subset of 18 serially imaged individuals (10 asymptomatic M+, 8 M−). We also analyzed associations between PiB retention and cerebrospinal fluid (CSF) Aβ concentrations in 17 M+ and 11 M− participants who underwent lumbar puncture and compared the findings to PiB‐PET and CSF Aβ in 37 autosomal dominant Alzheimer disease (ADAD) mutation carriers. Results D‐CAA M+ showed greater age‐dependent FLR PiB retention (p

Plasma amyloid-beta (Aβ) has long been investigated as a blood biomarker candidate for Cerebral Amyloid Angiopathy (CAA), however previous findings have been inconsistent which could be attributed to the use of less sensitive assays. This study investigates plasma Aβ alterations between pre-symptomatic Dutch-type hereditary CAA (D-CAA) mutation-carriers (MC) and non-carriers (NC) using two Aβ measurement platforms. Seventeen pre-symptomatic members of a D-CAA pedigree were assembled and followed up 3–4 years later (NC = 8, MC = 9). Plasma Aβ1-40 and Aβ1-42 were cross-sectionally and longitudinally analysed at baseline (T1) and follow-up (T2) and were found to be lower in MCs compared to NCs, cross-sectionally after adjusting for covariates, at both T1(Aβ1-40: p = 0.001, Aβ1-42: p = 0.0004) and T2 (Aβ1-40: p = 0.001, Aβ1-42: p = 0.016) employing the Single Molecule Array (Simoa) platform, however no significant differences were observed using the xMAP platform. Further, pairwise longitudinal analyses of plasma Aβ1-40 revealed decreased levels in MCs using data from the Simoa platform (p = 0.041) and pairwise longitudinal analyses of plasma Aβ1-42 revealed decreased levels in MCs using data from the xMAP platform (p = 0.041). Findings from the Simoa platform suggest that plasma Aβ may add value to a panel of biomarkers for the diagnosis of pre-symptomatic CAA, however, further validation studies in larger sample sets are required.

Highlights • Functional connectivity is diminished across the cortex in Dutch-type CAA. • Lower functional connectivity can already be found in presymptomatic CAA patients. • Decreased functional connectivity is most pronounced in symptomatic CAA patients., Cerebral amyloid angiopathy (CAA) is a major cause of intracerebral hemorrhage and neurological decline in the elderly. CAA results in focal brain lesions, but the influence on global brain functioning needs further investigation. Here we study functional brain connectivity in patients with Dutch type hereditary CAA using resting state functional MRI. Twenty-four DNA-proven Dutch CAA mutation carriers (11 presymptomatic, 13 symptomatic) and 29 age-matched control subjects were included. Using a set of standardized networks covering the entire cortex, we assessed both within- and between-network functional connectivity. We investigated group differences using general linear models corrected for age, sex and gray matter volume. First, all mutation carriers were contrasted against control subjects and subsequently presymptomatic- and symptomatic mutation carriers against control subjects separately, to assess in which stage of the disease differences could be found. All mutation carriers grouped together showed decreased connectivity in the medial and lateral visual networks, default mode network, executive control and bilateral frontoparietal networks. Symptomatic carriers showed diminished connectivity in all but one network, and between the left and right frontoparietal networks. Presymptomatic carriers also showed diminished connectivity, but only in the frontoparietal left network. In conclusion, global brain functioning is diminished in patients with CAA, predominantly in symptomatic CAA and can therefore be considered to be a late consequence of the disease.

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.

Cerebral amyloid angiopathy (CAA), where beta-amyloid (A beta)deposits around cerebral blood vessels, is a major contributor of vascular dysfunction in Alzheimer's disease (AD) patients. However, the molecular mechanism underlying CAA formation and CAA-induced cerebrovascular pathology is unclear. Hereditary cerebral amyloid angiopathy (HCAA) is a rare familial form of CAA in which mutations within the (A beta) peptide cause an increase in vascular deposits. Since the interaction between A beta and fibrinogen increases CAA and plays an important role in cerebrovascular damage in AD, we investigated the role of the A beta-fibrinogen interaction in HCAA pathology. Our work revealed the most common forms of HCAA-linked mutations, Dutch (E22Q) and Iowa (D23N), resulted in up to a 50-fold stronger binding affinity of A beta for fibrinogen. In addition, the stronger interaction between fibrinogen and mutant A beta s led to a dramatic perturbation of clot structure and delayed fibrinolysis. Immunofluorescence analysis of the occipital cortex showed an increase of fibrin(ogen)/A beta codeposition, as well as fibrin deposits in HCAA patients, compared to early-onset AD patients and nondemented individuals. Our results suggest the HCAA-type Dutch and Iowa mutations increase the interaction between fibrinogen and A beta, which might be central to cerebrovascular pathologies observed in HCAA.

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.

Hereditary cerebral hemorrhage with amyloidosis‐Dutch type (HCHWA‐D) is an early onset hereditary form of cerebral amyloid angiopathy (CAA) pathology, caused by the E22Q mutation in the amyloid β (Aβ) peptide. Transforming growth factor β1 (TGFβ1) is a key player in vascular fibrosis and in the formation of angiopathic vessels in transgenic mice. Therefore, we investigated whether the TGFβ pathway is involved in HCHWA‐D pathogenesis in human postmortem brain tissue from frontal and occipital lobes. Components of the TGFβ pathway were analyzed with quantitative RT‐PCR. TGFβ1 and TGFβ Receptor 2 (TGFBR2) gene expression levels were significantly increased in HCHWA‐D in comparison to the controls, in both frontal and occipital lobes. TGFβ‐induced pro‐fibrotic target genes were also upregulated. We further assessed pathway activation by detecting phospho‐SMAD2/3 (pSMAD2/3), a direct TGFβ down‐stream signaling mediator, using immunohistochemistry. We found abnormal pSMAD2/3 granular deposits specifically on HCHWA‐D angiopathic frontal and occipital vessels. We graded pSMAD2/3 accumulation in angiopathic vessels and found a positive correlation with the CAA load independent of the brain area. We also observed pSMAD2/3 granules in a halo surrounding occipital vessels, which was specific for HCHWA‐D. The result of this study indicates an upregulation of TGFβ1 in HCHWA‐D, as was found previously in AD with CAA pathology. We discuss the possible origins and implications of the TGFβ pathway deregulation in the microvasculature in HCHWA‐D. These findings identify the TGFβ pathway as a potential biomarker of disease progression and a possible target of therapeutic intervention in HCHWA‐D.

Familial British dementia (FBD) and familial Danish dementia (FDD) are caused by mutations in the BRI2 gene. These diseases are characterized clinically by progressive dementia and ataxia and neuropathologically by amyloid deposits and neurofibrillary tangles. Herein, we investigate BRI2 protein accumulation in FBD, FDD, Alzheimer disease and Gerstmann-Sträussler-Scheinker disease. In FBD and FDD, we observed reduced processing of the mutant BRI2 pro-protein, which was found accumulating intracellularly in the Golgi of neurons and glial cells. In addition, we observed an accumulation of a mature form of BRI2 protein in dystrophic neurites, surrounding amyloid cores. Accumulation of BRI2 was also observed in dystrophic neurites of Alzheimer disease and Gerstmann-Sträussler-Scheinker disease cases. Although it remains to be determined whether intracellular accumulation of BRI2 may lead to cell damage in these degenerative diseases, our study provides new insights into the role of mutant BRI2 in the pathogenesis of FBD and FDD and implicates BRI2 as a potential indicator of neuritic damage in diseases characterized by cerebral amyloid deposition.

Previous work suggests that impairments of cerebrovascular flow or reactivity might be early markers of cerebral amyloid angiopathy (CAA). Hereditary cerebral haemorrhage with amyloidosis-Dutch type (HCHWA-D) is a genetic form of CAA that can be diagnosed before the onset of clinical symptoms by DNA testing. We aimed to investigate whether haemodynamic measures are decreased in presymptomatic and symptomatic HCHWA-D mutation carriers compared with healthy controls.In this case-control study, we included presymptomatic and symptomatic HCHWA-D mutation carriers diagnosed through genetic testing and recruited through the HCHWA-D patient association (Katwijk, Netherlands) and the outpatient clinic of the Department of Neurology of the Leiden University Medical Center (Leiden, Netherlands), and healthy controls. We measured regional cerebral blood flow (rCBF) using pseudo-continuous arterial spin labelling. Quantitative flow was measured by phase-contrast magnetic resonance angiography of the cerebropetal vessels. Vascular reactivity was established by measuring changes in blood-oxygen-level-dependent (BOLD) signal after visual stimulation. Data from presymptomatic and symptomatic individuals were compared with healthy controls using mixed-model regression analysis.Between May 15, 2012, and December 22, 2015, we investigated cross-sectional imaging data from 27 HCHWA-D mutation carriers (12 presymptomatic and 15 symptomatic) and 33 healthy controls. Compared with controls, symptomatic HCHWA-D carriers had significantly decreased cortical grey matter rCBF in the occipital lobe (mean difference -11·1 mL/100 g per min, 95% CI -2·8 to -19·3; uncorrected p=0·010) and decreased flux in the basilar artery (mean difference -0·9 mL/s, 95% CI -1·5 to -0·2; uncorrected p=0·019). However, we noted no changes in rCBF and flux in presymptomatic carriers compared with controls. Vascular reactivity was significantly decreased in the occipital lobe in both presymptomatic (mean BOLD change 1·1% [SD 0·5], mean difference -0·4% change, 95% CI -0·7 to -0·2; p=0·001; mean time to baseline 10·1 s [SD 7·6], mean difference 4·6 s, 95% CI 0·4 to 8·8; p=0·032) and symptomatic carriers (mean BOLD change 0·4% [SD 0·1], mean difference -0·9%, 95% CI -1·1 to -0·6; p0·0001; mean time to baseline 20·3 s [SD 8·4], mean difference 13·1 s, 95% CI 9·4 to 16·9; p0·0001) compared with controls; however, the difference in mean time to peak was only significant for symptomatic carriers (mean difference 12·2 s, 95% CI 8·6 to 15·9; p0·0001).Our findings suggest that determination of vascular reactivity might be a useful biomarker for early detection of vascular amyloid pathology in sporadic CAA, and a biomarker of efficacy in future intervention trials. Our data indicate that vascular reactivity measurements might be useful for differential diagnosis in dementia to determine the vascular component.USA National Institutes of Health.

OBJECTIVES: To determine the frequency of rare and pertinent disease-causing variants in small vessel disease (SVD)-associated genes (such as NOTCH3, HTRA1, COL4A1, COL4A2, FOXC1, TREX1, and GLA) in cerebral SVD, we performed targeted gene sequencing in 950 patients with younger-onset apparently sporadic SVD stroke using a targeted sequencing panel. METHODS: We designed a high-throughput sequencing panel to identify variants in 15 genes (7 known SVD genes, 8 SVD-related disorder genes). The panel was used to screen a population of 950 patients with younger-onset (≤70 years) MRI-confirmed SVD stroke, recruited from stroke centers across the United Kingdom. Variants were filtered according to their frequency in control databases, predicted effect, presence in curated variant lists, and combined annotation dependent depletion scores. Whole genome sequencing and genotyping were performed on a subset of patients to provide a direct comparison of techniques. The frequency of known disease-causing and pertinent variants of uncertain significance was calculated. RESULTS: We identified previously reported variants in 14 patients (8 cysteine-changing NOTCH3 variants in 11 patients, 2 HTRA1 variants in 2 patients, and 1 missense COL4A1 variant in 1 patient). In addition, we identified 29 variants of uncertain significance in 32 patients. CONCLUSION: Rare monogenic variants account for about 1.5% of younger onset lacunar stroke. Most are cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy variants, but the second most common gene affected is HTRA1. A high-throughput sequencing technology platform is an efficient, reliable method to screen for such mutations.