scholarly journals Understanding the Pathophysiology of Cerebral Amyloid Angiopathy

2020 ◽  
Vol 21 (10) ◽  
pp. 3435
Author(s):  
Laura Gatti ◽  
Francesca Tinelli ◽  
Emma Scelzo ◽  
Francesco Arioli ◽  
Giuseppe Di Fede ◽  
...  

Cerebral amyloid angiopathy (CAA), one of the main types of cerebral small vessel disease, is a major cause of spontaneous intracerebral haemorrhage and an important contributor to cognitive decline in elderly patients. Despite the number of experimental in vitro studies and animal models, the pathophysiology of CAA is still largely unknown. Although several pathogenic mechanisms including an unbalance between production and clearance of amyloid beta (Aβ) protein as well as ‘the prion hypothesis’ have been invoked as possible disease triggers, they do not explain completely the disease pathogenesis. This incomplete disease knowledge limits the implementation of treatments able to prevent or halt the clinical progression. The continuous increase of CAA patients makes imperative the development of suitable experimental in vitro or animal models to identify disease biomarkers and new pharmacological treatments that could be administered in the early disease stages to prevent irreversible changes and disease progression.

2021 ◽  
pp. 1-15
Author(s):  
Manu J. Sharma ◽  
Brandy L. Callahan

Background: Mild cognitive impairment (MCI) is considered by some to be a prodromal phase of a progressive disease (i.e., neurodegeneration) resulting in dementia; however, a substantial portion of individuals (ranging from 5–30%) remain cognitively stable over the long term (sMCI). The etiology of sMCI is unclear but may be linked to cerebrovascular disease (CVD), as evidence from longitudinal studies suggest a significant proportion of individuals with vasculopathy remain stable over time. Objective: To quantify the presence of neurodegenerative and vascular pathologies in individuals with long-term (>5-year) sMCI, in a preliminary test of the hypothesis that CVD may be a contributor to non-degenerative cognitive impairment. We expect frequent vasculopathy at autopsy in sMCI relative to neurodegenerative disease, and relative to individuals who convert to dementia. Methods: In this retrospective study, using data from the National Alzheimer’s Coordinating Center, individuals with sMCI (n = 28) were compared to those with MCI who declined over a 5 to 9-year period (dMCI; n = 139) on measures of neurodegenerative pathology (i.e., Aβ plaques, neurofibrillary tangles, TDP-43, and cerebral amyloid angiopathy) and CVD (infarcts, lacunes, microinfarcts, hemorrhages, and microbleeds). Results: Alzheimer’s disease pathology (Aβ plaques, neurofibrillary tangles, and cerebral amyloid angiopathy) was significantly higher in the dMCI group than the sMCI group. Microinfarcts were the only vasculopathy associated with group membership; these were more frequent in sMCI. Conclusion: The most frequent neuropathology in this sample of long-term sMCI was microinfarcts, tentatively suggesting that silent small vessel disease may characterize non-worsening cognitive impairment.


2015 ◽  
Vol 36 (3) ◽  
pp. 576-580 ◽  
Author(s):  
Susanne J van Veluw ◽  
Geert Jan Biessels ◽  
Willem H Bouvy ◽  
Wim GM Spliet ◽  
Jaco JM Zwanenburg ◽  
...  

Perivascular spaces are an emerging marker of small vessel disease. Perivascular spaces in the centrum semiovale have been associated with cerebral amyloid angiopathy. However, a direct topographical relationship between dilated perivascular spaces and cerebral amyloid angiopathy severity has not been established. We examined this association using post-mortem magnetic resonance imaging in five cases with evidence of cerebral amyloid angiopathy pathology. Juxtacortical perivascular spaces dilation was evaluated on T2 images and related to cerebral amyloid angiopathy severity in overlying cortical areas on 34 tissue sections stained for Amyloid β. Degree of perivascular spaces dilation was significantly associated with cerebral amyloid angiopathy severity (odds ratio = 3.3, 95% confidence interval 1.3–7.9, p = 0.011). Thus, dilated juxtacortical perivascular spaces are a promising neuroimaging marker of cerebral amyloid angiopathy severity.


2019 ◽  
Vol 12 ◽  
pp. 175628641984411 ◽  
Author(s):  
Szu-Ju Chen ◽  
Hsin-Hsi Tsai ◽  
Li-Kai Tsai ◽  
Sung-Chun Tang ◽  
Bo-Chin Lee ◽  
...  

Cerebral amyloid angiopathy (CAA) is a cerebral small vessel disease caused by β -amyloid (Aβ) deposition at the leptomeningeal vessel walls. It is a common cause of spontaneous intracerebral hemorrhage and a frequent comorbidity in Alzheimer’s disease. The high recurrent hemorrhage rate in CAA makes it very important to recognize this disease to avoid potential harmful medication. Imaging studies play an important role in diagnosis and research of CAA. Conventional computed tomography and magnetic resonance imaging (MRI) methods reveal anatomical alterations, and remains as the most reliable tool in identifying CAA according to modified Boston criteria. The vascular injuries of CAA result in both hemorrhagic and ischemic manifestations and related structural changes on MRI, including cerebral microbleeds, cortical superficial siderosis, white matter hyperintensity, MRI-visible perivascular spaces, and cortical microinfarcts. As imaging techniques advance, not only does the resolution of conventional imaging improve, but novel skills in functional and molecular imaging studies also enable in vivo analysis of vessel physiological changes and underlying pathology. These modern tools help in early detection of CAA and may potentially serve as sensitive outcome markers in future clinical trials. In this article, we reviewed past studies of CAA focusing on utilization of various conventional and novel imaging techniques in both research and clinical aspects.


Neurology ◽  
2017 ◽  
Vol 88 (23) ◽  
pp. 2162-2168 ◽  
Author(s):  
Marco Pasi ◽  
Gregoire Boulouis ◽  
Panagiotis Fotiadis ◽  
Eitan Auriel ◽  
Andreas Charidimou ◽  
...  

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.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Ah-Ling Cheng ◽  
Cheryl R McCreary ◽  
M. L Lauzon ◽  
Richard Frayne ◽  
Mayank Goyal ◽  
...  

Introduction: Case examples and small case series suggest that MRI susceptibility weighted imaging (SWI) may be more sensitive for cerebral microbleed (CMB) detection compared to MRI T2* gradient-recalled echo (GRE). However, there are few data on CMB counts measured by SWI vs. GRE, or inter-rater reliability, in groups of patients with cerebral small vessel disease. We used data from a prospective cohort study of cerebral amyloid angiopathy (CAA), a cerebral small-vessel disease marked by high numbers of CMBs, to quantify the sensitivity and reliability of SWI vs. GRE for CMB detection. Methods: Nine patients with symptomatic CAA (mean age 71±8.3; 7 males and 2 females) and 21 healthy non-CAA controls (mean age 68±6.3; 10 M/11 F) underwent T2* GRE and SWI on a 3.0T MR scanner. Probable CAA was diagnosed according to the Boston criteria prior to study entry using information from clinical MRI with GRE sequences. Two raters (labeled 1 and 2) independently interpreted the GRE and SWI scans blinded to clinical information. The phase-filtered magnitude image was used for SWI interpretation. Agreement reliability was assessed using the kappa coefficient (where a kappa of ≥0.60 indicates good agreement) or the intraclass correlation coefficient (ICC). Results: Overall, the raters identified 1,432 CMBs in the 9 CAA cases (range 1-434 per patient) and 8 CMBs in the healthy controls (range 0-3). Rater 1 identified CMBs in 5/21 healthy controls on SWI and 5/21 on GRE, while rater 2 identified CMBs in 4/21 on SWI and 3/21 on GRE (kappa 0.70 for GRE and 0.57 for SWI). In CAA cases more CMBs were seen on SWI compared to the GRE sequence but the difference was significant only for rater 1 (rater 1: on average 85% more per patient on SWI than on GRE, p=0.008; rater 2: 19% more, p=0.25). Among CAA cases the reliability between raters was poor for GRE (ICC 0.36) but excellent for SWI (0.94, p<0.05 for comparison with GRE). Review suggested that the differing reliability was because rater 1 was less likely than rater 2 to identify faint lesions on GRE as CMB, whereas these lesions were more conspicuous on SWI. If SWI rather than GRE were used to determine CAA status according to the Boston criteria, all 9 CAA cases would remain classified as probable CAA but 2/21 controls would be reclassified as either possible (n=1) or probable (n=1) asymptomatic CAA based on the detection of one or more lobar microbleeds on SWI. Conclusions: SWI confers greater reliability as well as greater sensitivity for CMB detection compared to GRE, and should be the preferred sequence for quantifying CMBs. SWI may more frequently identify lobar microbleeds that could represent asymptomatic CAA. Further research is needed to determine whether the Boston criteria require revision to take into account the greater sensitivity of SWI for CMB detection.


2021 ◽  
pp. 174749302199196
Author(s):  
EA Koemans ◽  
S Voigt ◽  
I Rasing ◽  
WMT Jolink ◽  
TW van Harten ◽  
...  

Background and aim To investigate whether a striped occipital cortex and intragyral hemorrhage, two markers recently detected on ultra-high-field 7-tesla-magnetic resonance imaging in hereditary cerebral amyloid angiopathy (CAA), also occur in sporadic CAA (sCAA) or non-sCAA intracerebral hemorrhage (ICH). Methods We performed 7-tesla-magnetic resonance imaging in patients with probable sCAA and patients with non-sCAA-ICH. Striped occipital cortex (linear hypointense stripes perpendicular to the cortex) and intragyral hemorrhage (hemorrhage restricted to the juxtacortical white matter of one gyrus) were scored on T2*-weighted magnetic resonance imaging. We assessed the association between the markers, other CAA-magnetic resonance imaging markers and clinical features. Results We included 33 patients with sCAA (median age 70 years) and 29 patients with non-sCAA-ICH (median age 58 years). Striped occipital cortex was detected in one (3%) patient with severe sCAA. Five intragyral hemorrhages were found in four (12%) sCAA patients. The markers were absent in the non-sCAA-ICH group. Patients with intragyral hemorrhages had more lobar ICHs (median count 6.5 vs. 1.0), lobar microbleeds (median count >50 vs. 15), and lower median cognitive scores (Mini Mental State Exam: 20 vs. 28, Montreal Cognitive Assessment: 18 vs. 24) compared with patients with sCAA without intragyral hemorrhage. In 12 (36%) patients, sCAA diagnosis was changed to mixed-type small vessel disease due to deep bleeds previously unobserved on lower field-magnetic resonance imaging. Conclusion Whereas a striped occipital cortex is rare in sCAA, 12% of patients with sCAA have intragyral hemorrhages. Intragyral hemorrhages seem to be related to advanced disease and their absence in patients with non-sCAA-ICH could suggest specificity for CAA.


BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e042550
Author(s):  
Kana Matsuda ◽  
Akihiro Shindo ◽  
Yuichiro Ii ◽  
Ken-ichi Tabei ◽  
Yukito Ueda ◽  
...  

ObjectiveThe severity of cerebral small vessel disease (SVD) is assessed through neuroimaging findings, including hypertensive arteriopathy (HA)-SVD and cerebral amyloid angiopathy (CAA)-SVD. HA-SVD and CAA-SVD have been collectively estimated as total scores: the HA-SVD and CAA-SVD scores, respectively. Previous reports suggest that HA-SVD scores are associated with cognitive function; however, the relationship between CAA-SVD scores and cognitive function remains unclear. Therefore, we examined the association between CAA-SVD scores and cognitive function. Furthermore, we developed a modified CAA-SVD score considering cortical microinfarcts and posterior dominant white matter hyperintensities, which are imaging findings of CAA, and examined the association between these scores and cognitive function in the same patient group.DesignProspective study.SettingSingle centre study from a memory clinic.ParticipantsSubjects were diagnosed with mild cognitive impairment (MCI) or mild dementia in our memory clinic between February 2017 and July 2019 and underwent clinical dementia rating scale and brain MRI assessment. A total of 42 patients (aged 75.3±9.12 years) were registered prospectively.Primary and secondary outcome measuresWe evaluated intellectual function, memory, frontal lobe function and constructional ability. Furthermore, the relationship between each score and cognitive function was examined.ResultsThe CAA-SVD score showed significant associations with cognitive function (R2=0.63, p=0.016), but the HA-SVD score did not (R2=0.41, p=0.35). The modified CAA-SVD score was also significantly associated with cognitive function (R2=0.65, p=0.008).ConclusionCognitive function is associated with the CAA-SVD score, and more efficiently with the modified CAA-SVD score, in memory clinic patients. Although we have not validated the weighting of the modified CAA-SVD score, these scores can be a predictor of cognitive deterioration in patients with MCI and mild dementia.


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