Longitudinal Progression of Magnetic Resonance Imaging Markers and Cognition in Dutch-Type Hereditary Cerebral Amyloid Angiopathy.

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<0.001). In contrast, no significant changes in hemorrhagic markers, ischemic markers, cerebral blood flow, and cognition were found. In symptomatic D-CAA mutation carriers, the number of intracerebral hemorrhages increased over the 4-year period (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.

Innovative Magnetic Resonance Imaging Markers of Hereditary Cerebral Amyloid Angiopathy at 7 Tesla.

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 T2*-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<0.001), and a higher incidence of specific cortical changes (40% [6/15] versus 0% [0/29], P<0.005). In presymptomatic HCHWA-D-mutation carriers, the prevalence of none of these markers was increased compared with control subjects. 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.

Early Magnetic Resonance Imaging and Cognitive Markers of Hereditary Cerebral Amyloid Angiopathy.

BACKGROUND AND PURPOSE: Early markers for cerebral amyloid angiopathy are largely unknown. We aimed to identify which magnetic resonance imaging (MRI) (performed at 7 and 3T) and cognitive markers are an early sign in (pre) symptomatic subjects with hereditary cerebral hemorrhage with amyloidosis-Dutch type. METHODS: Twenty-seven DNA-proven Dutch-type mutation carriers (15 symptomatic and 12 presymptomatic) (mean age of 45.9 years) and 33 controls (mean age of 45.6 years) were included. 7T and 3T MRI was performed, cerebral amyloid angiopathy and small-vessel disease type MRI markers were estimated, and cognitive performance was assessed. Univariate general linear modeling analysis was used to assess the association between MRI markers and cognitive performance on the one hand and on the other, mutation status, adjusted for age, sex, and education. RESULTS: In symptomatic patients, all established cerebral amyloid angiopathy MRI markers (microbleeds, intracerebral hemorrhages, subarachnoid hemorrhages, superficial siderosis, microinfarcts, volume of white matter hyperintensities, and dilated perivascular spaces in centrum semiovale) were increased compared with controls (P<0.05). In presymptomatic subjects, the prevalence of microinfarcts and median volume of white matter hyperintensities were increased in comparison to controls (P<0.05). Symptomatic patients performed worse on all cognitive domains, whereas presymptomatic subjects did not show differences in comparison with controls (P<0.05). CONCLUSIONS: White matter hyperintensities and microinfarcts are more prevalent among presymptomatic subjects and precede cognitive and neuropsychiatric symptoms and intracerebral hemorrhages.

Neurovascular coupling in early stage dementia - A case-control study.

Cerebral amyloid angiopathy (CAA) is frequently found post mortem in Alzheimer's dementia, but often undetected during life especially since in vivo hallmarks of CAA and its vascular damage become overt relatively late in the disease process. Decreased neurovascular coupling to visual stimulation has been put forward as an early MRI marker for CAA disease severity. The current study investigates the role of neurovascular coupling in AD related dementia and its early stages. We included 25 subjective cognitive impairment, 33 mild cognitive impairment and 17 dementia patients and 44 controls. All participants underwent magnetic resonance imaging of the brain and neuropsychological assessment. Univariate general linear modeling analyses were used to assess neurovascular coupling between patient groups and controls. Moreover, linear regression analyses was used to assess the associations between neurovascular coupling and cognition. Our data show that BOLD amplitude is lower in dementia (mean 0.8 ± 0.2, p = 0.001) and MCI patients (mean 0.9 ± 0.3, p = 0.004) compared with controls (mean 1.1 ± 0.2). A low BOLD amplitude was associated with low scores in multiple cognitive domains. We conclude that cerebrovascular dysfunction, most likely due CAA, is an important comorbidity in early stages of dementia and has an independent effect on cognition.

Age-related and regional changes of aortic stiffness in the Marfan syndrome: assessment with velocity-encoded MRI.

PURPOSE: To study age-related change in aortic stiffness in patients with Marfan syndrome (MFS) versus healthy volunteers using velocity-encoded (VE) MRI. MATERIALS AND METHODS: Twenty-five MFS patients (age range, 18-63 years; mean age 36 ± 14 years, 13 men) and 25 age-/gender-matched healthy volunteers were examined with VE-MRI. Aortic stiffness was expressed by pulse wave velocity (PWV), assessed in the proximal and distal part of the aorta and in the total aorta. PWV was compared between patients and volunteers and age-relation was determined by linear regression. RESULTS: PWV was significantly higher in all parts of the aorta in patients when compared with healthy volunteers (proximal aorta 5.7 ± 1.5 m/s versus 4.8 ± 0.9 m/s, distal aorta 6.4 ± 2.4 m/s versus 5.0 ± 1.2 m/s and total aorta 5.9 ± 1.7 m/s versus 4.9 ± 1.1 m/s, all P < 0.004). PWV correlated significantly with age (Pearson R between 0.45 and 0.94). Only in the proximal aorta, the increase in PWV with age was significantly higher in patients (7 ± 2 cm/s increase with age) than in volunteers (3 ± 1 cm/s increase, P = 0.03); in the distal or total aorta, the increase in PWV with age was not different between patients and volunteers. CONCLUSION: Velocity-encoded MRI detects more pronounced age-related aortic stiffening in the proximal aorta in MFS patients versus healthy volunteers, suggesting more severe wall disease in MFS.

Subjective Cognitive Decline Is Associated with Greater White Matter Hyperintensity Volume.

BACKGROUND: Research in older adults with subjective cognitive decline (SCD) has mainly focused on Alzheimer's disease (AD)-related MRI markers, such as hippocampal volume. However, small vessel disease (SVD) is currently established as serious comorbidity in dementia and its preliminary stages. It is therefore important to examine SVD markers in addition to AD markers in older adults presenting with SCD. OBJECTIVE: The aim of our study was to elucidate the role of SVD markers in late middle-aged to older adults with and without SCD in addition to the commonly found role of AD markers (hippocampal volume). METHODS: 67 healthy late middle-aged to older adults participated in this study (mean age 68 years); 25 participants with SCD and 42 participants without SCD. We evaluated quantitative as well as qualitative AD markers (i.e., hippocampal volume and medial temporal lobe atrophy (MTA) scale) and SVD markers (i.e., white matter hyperintensities (WMH) volume, Fazekas scale, microbleeds, and lacunar infarcts), and neuropsychological function and amount of memory complaints. RESULTS: We found a significant effect of SCD on hippocampal atrophy, as assessed using the MTA scale, but not on hippocampal volume. In addition, we found a significant effect of SCD, and amount of memory complaints, on WMH volume and Fazekas score, suggesting larger WMH volumes in participants with SCD. CONCLUSION: SVD MRI markers are related to amount of memory complaints, in addition to the commonly observed AD MRI markers, as demonstrated by the greater WMHs in healthy late middle-aged to older adults with SCD.

Cerebrovascular function in presymptomatic and symptomatic individuals with hereditary cerebral amyloid angiopathy: a case-control study.

BACKGROUND: 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. METHODS: 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. FINDINGS: 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; p<0·0001; mean time to baseline 20·3 s [SD 8·4], mean difference 13·1 s, 95% CI 9·4 to 16·9; p<0·0001) 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; p<0·0001). INTERPRETATION: 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. FUNDING: USA National Institutes of Health.

Accurate and reproducible mitral valvular blood flow measurement with three-directional velocity-encoded magnetic resonance imaging.

A new method for quantifying the transvalvular flow through the mitral valve (MV) based on three-directional velocity-encoded magnetic resonance imaging (MRI) is presented. For thirty time phases during one cardiac cycle, the three-dimensional (3D) velocity vector field of the blood flow is reconstructed from the MRI measurement. Retrospectively, for each time phase, the MV-plane is indicated manually in the velocity data and the flow through this plane is determined, representing the MV flow. Measurements are performed in 10 healthy volunteers. The new method is compared to the conventional, one-directional velocity-encoded MRI method for which an acquisition plane is positioned at the mitral valve at end-systole and remains fixed during the acquisition. The flow measurements with the new method correlate very well with the flow measured in the aorta (r(p)=0.92, p<0.01), whereas the conventional method shows no statistically significant correlation (r(p)=0.15, p=0.68). The low differences between the flow measured at the MV and the flow in the aorta proves high accuracy of the new method. Also, the new method shows very low intra- and interobserver variation, proving the high reproducibility. Three-directional velocity-encoded MRI is a patient-friendly and easy-to-use method suitable for quantifying accurately and reproducibly the transvalvular MV flow.