Brain Microvasculature Involvement in ANCA Positive Vasculitis

2016 ◽  
Vol 41 (5-6) ◽  
pp. 313-321 ◽  
Author(s):  
Inés González-Suárez ◽  
Javier Arpa ◽  
Juan José Ríos-Blanco
Keyword(s):  
Blood Flow ◽  
White Matter ◽  
Endothelial Dysfunction ◽  
Arterial Stiffness ◽  
Linear Regression Analysis ◽  
Brain Mri ◽  
Mean Flow ◽  
Brain Involvement ◽  
Brain Microvasculature ◽  
The Brain

Objective: Endothelial dysfunction is associated with arterial stiffness, a factor that is increasingly recognised as an important determinant of cardiovascular risk. High-flow organs such as the brain and kidneys are particularly sensitive to excessive pressure and flow pulsatility. High, local blood flow is associated with low microvascular impedance, which facilitates the penetration of excessive pulsatile energy into the microvascular bed leading to tissue damage. Systemic endothelial dysfunction and arterial stiffness have been demonstrated in peripheral vessels in associated vasculitis (AAV). Although, the brain involvement is not infrequent in AAV, it has not been evaluated previously. Our aim is to evaluate the involvement of the brain microvasculature in AAV. Methods: Twenty-three patients with inactive AAV were studied. Brain blood flow was assessed by transcranial Doppler (TCD) and single-photon positron emission tomography (SPECT), structural brain involvement by brain MRI and cognitive scores by Montreal Cognitive Assessment (MoCA) test. Results: Lower mean flow velocity (MFV) was associated to altered SPECT perfusion, higher white matter changes (WMC), lower MoCA scores and younger age (p < 0.05). Middle cerebral artery pulsatility index (MCA-PI) was related to hypertension, diabetes, lower scores on MoCA, increased vasculitis damage index (VDI) and perfusion impairment in SPECT (p < 0.05). These data were reproduced for all intracranial arteries. Up to 88.9% of patients had WMC on MRI. A higher lesion load was associated with age, decreased MoCA and fewer MFV with higher PI. The multivariable linear regression analysis showed that the greater the lesion loads, greater the bifrontal atrophy, MCA-PI and lower MoCA scores. Up to 60.9% of patients presented a decreased MoCA score (p = 0.012). It appeared to be related to VDI (p = 0.04), WMC (p = 0.004) and altered SPECT (p = 0.05). Conclusions: The alterations in brain perfusion SPECT, the presence of white matter lesions on MRI, as well as increased PI and RI with lower MFV of the cerebral vessels in TCD suggest the presence of microangiopathy in asymptomatic AAV that could lead to cognitive impairment.

scholarly journals Arterial stiffness and dementia pathology

Neurology ◽  
2018 ◽  
Vol 90 (14) ◽  
pp. e1248-e1256 ◽  
Author(s):  
Timothy M. Hughes ◽  
Lynne E. Wagenknecht ◽  
Suzanne Craft ◽  
Akiva Mintz ◽  
Gerardo Heiss ◽  
...  
Keyword(s):  
White Matter ◽  
Arterial Stiffness ◽  
Small Vessel Disease ◽  
Brain Mri ◽  
Volume Ratio ◽  
Cognitive Testing ◽  
White Matter Hyperintensity ◽  
Cross Sectional ◽  
Brain Volumes ◽  
Atherosclerosis Risk In Communities

ObjectiveArterial stiffness has been associated with evidence of cerebral small vessel disease (cSVD) and fibrillar β-amyloid (Aβ) deposition in the brain. These complex relationships have not been examined in racially and cognitively diverse cohorts.MethodsThe Atherosclerosis Risk in Communities (ARIC)–Neurocognitive Study collected detailed cognitive testing for adjudication of dementia and mild cognitive impairment (MCI), brain MRI, and arterial stiffness by pulse wave velocity (PWV, carotid-femoral [cfPWV] and heart-carotid [hcPWV]). The ARIC-PET ancillary study added Aβ imaging using florbetapir ([18F]-AV-45) to obtain standardized uptake volume ratios and defined global Aβ-positivity as standardized uptake volume ratio >1.2. One-SD increase in PWV was related to brain volume, MRI-defined cSVD (e.g., cerebral microbleeds and white matter hyperintensity), and cortical Aβ deposition adjusted for age, body mass index, sex, race, and APOE ε4 status. We examined the cross-sectional relationships including interactions by race, APOE ε4 status, and cognition.ResultsAmong the 320 ARIC-PET participants (76 [5] years, 45% black, 27% MCI), greater central stiffness (hcPWV) was associated with greater Aβ deposition (odds ratio [OR] = 1.31, 95% confidence interval [CI] 1.01–1.71). Greater central stiffness (cfPWV) was significantly associated with having lower brain volumes in Alzheimer disease–susceptible regions (in mm3, β = −1.5 [0.7 SD], p = 0.03) and high white matter hyperintensity burden (OR = 1.6, 95% CI 1.2–2.1). Furthermore, cfPWV was associated with a higher odds of concomitant high white matter hyperintensity and Aβ-positive scans (OR = 1.4, 95% CI 1.1–2.1). These associations were strongest among individuals with MCI and did not differ by race or APOE ε4 status.ConclusionsArterial stiffness, measured by PWV, is an emerging risk factor for dementia through its repeated relationships with cognition, cSVD, and Aβ deposition.

scholarly journals Pelizaeus-Merzbacher Disease: A Case Report

2020 ◽  
Author(s):  
Ghazaleh Jamalipour Soufi ◽  
Siavash Iravan
Keyword(s):  
Case Report ◽  
White Matter ◽  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Proteolipid Protein ◽  
Radiology Department ◽  
Magnetic Resonance Imaging Mri ◽  
Normal White Matter ◽  
Pelizaeus Merzbacher Disease ◽  
The Brain

Pelizaeus-Merzbacher Disease (PMD), as a rare genetically x-linked leukodystrophy, is a disorder of proteolipid protein expression in myelin formation. This disorder is clinically presented by neurodevelopmental delay and abnormal pendular eye movements. The responsible gene for this disorder is the proteolipid protein gene (PLP1). Our case was a oneyear-old boy referred to the radiology department for evaluating the Central Nervous System (CNS) development by brain Magnetic Resonance Imaging (MRI). Clinically, he demonstrated neuro-developmental delay symptoms. The brain MRI results indicated a diffuse lack of normal white matter myelination. This case report should be considered about the possibilityof PMD in the brain MRI of patients who present a diffuse arrest of normal white matter myelination.

Mitochondrial disorders, MRI of the brain and limb muscles in type 1 myotonic dystrophy

2020 ◽  
pp. 66-67
Author(s):  
М.С. Бунак ◽  
С.В. Котов ◽  
И.А. Василенко ◽  
О.П. Сидорова ◽  
Е.В. Бородатая ◽  
...  
Keyword(s):  
White Matter ◽  
Myotonic Dystrophy ◽  
Brain Mri ◽  
Mitochondrial Disorders ◽  
Calf Muscle ◽  
Medial Head ◽  
Limb Muscles ◽  
The Brain

При миотонической дистрофии выявлены митохондриальные нарушения, которые могут быть причиной поражения белого вещества головного мозга. При МРТ мышц конечностей у больных выявлено наиболее частое поражение - медиальная головка икроножной мышцы. In patients with myotonic dystrophy, mitochondrial disorders were detected, which could be the cause of lesions of the white matter of the brain. MRI of limb muscles in patients revealed the most frequent lesion of the medial head of the calf muscle.

Carotid Arterial Stiffness and Cerebral Blood Flow in Amnestic Mild Cognitive Impairment

2021 ◽  
Vol 17 (12) ◽  
pp. 1115-1125
Author(s):  
Tsubasa Tomoto ◽  
Jun Sugawara ◽  
Takashi Tarumi ◽  
Collin Chiles ◽  
Bryon Curtis ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Arterial Stiffness ◽  
Linear Regression Analysis ◽  
Systolic Pressure ◽  
Amnestic Mild Cognitive Impairment ◽  
Stiffness Index ◽  
Carotid Arterial

Background: Central arterial stiffness is an emerging risk factor of age-related cognitive impairment and Alzheimer’s disease (AD). However, the underlying pathophysiological mechanisms remain unclear. Objective: We tested the hypothesis that carotid arterial stiffness is associated with reduced cerebral blood flow (CBF) and increased cerebrovascular resistance (CVR) in patients with amnestic mild cognitive impairment (MCI), a prodromal stage of AD. Methods: Fifty-four patients with amnestic MCI and 24 cognitively normal subjects (CN) of similar age and sex to MCI patients underwent measurements of CBF and carotid β-stiffness index using ultrasonography and applanation tonometry. Total CBF was measured as the sum of CBF from both the internal carotid and vertebral arteries, and divided by total brain tissue mass (assessed with MRI) to obtain normalized CBF (nCBF). Results: Relative to CN subjects, MCI patients showed lower nCBF (53.3 ± 3.2 vs 50.4±3.4 mL/100 g/min, P < 0.001) and higher CVR (0.143 ± 0.019 vs 0.156 ± 0.023 mmHg/mL/min, P < 0.015). Multiple linear regression analysis showed that nCBF was negatively associated with carotid β-stiffness index (B = -0.822, P < 0.001); CVR was positively associated with carotid systolic pressure (B = 0.001, P < 0.001) after adjustment for age, sex, body mass index, and MCI status. Conclusion: These findings suggest that carotid artery stiffening may contribute at least in part to the reduced nCBF and increased CVR in patients with MCI associated with augmented carotid arterial pulsatility.

scholarly journals Normalization of Cerebral Blood Flow, Neurochemicals, and White Matter Integrity After Kidney Transplantation

2020 ◽  
Author(s):  
Rebecca J. Lepping ◽  
Robert N. Montgomery ◽  
Palash Sharma ◽  
Jonathan D. Mahnken ◽  
Eric D. Vidoni ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Kidney Transplantation ◽  
White Matter ◽  
Kidney Disease ◽  
Brain Mri ◽  
White Matter Integrity ◽  
Healthy Controls ◽  
Brain Abnormalities ◽  
Increased Risk

AbstractBackgroundChronic kidney disease (CKD) is associated with abnormalities in cerebral blood flow (CBF), cerebral neurochemical concentrations and white matter integrity, each of which are associated with adverse clinical consequences in the non-CKD population, and may explain the high prevalence of dementia and stroke in end stage kidney disease (ESKD). Since cognition improves after kidney transplantation (KT), we examined these brain abnormalities pre-to post-KT to identify potential reversibility in ESKD-associated brain abnormalities.MethodsWe measured the effects of KT on CBF assessed by arterial spin labeling, cerebral neurochemical concentrations (N-acetylaspartate, choline, glutamate and glutamine, myoinositol and total creatine) measured by magnetic resonance spectroscopic imaging, and white matter integrity measured by fractional anisotropy (FA) and mean diffusivity (MD) with diffusion tensor imaging. We used a linear mixed model analysis to compare longitudinal, repeated brain MRI measurements pre-KT, and 3 months and 12 months post-KT, and also compared findings with healthy controls.Results29 ESKD patients and 19 age-matched healthy controls participated in the study. 22 patients underwent post-KT MRI. CBF, which was higher pre-KT than in controls (p=0.003), decreased post-KT (p<0.0001) to values in controls. KT also normalized concentrations of osmotic neurochemicals choline (p<0.0001) and myo-inositol (p=0.0003) that were higher pre-KT compared to controls. Post-KT, FA increased (p=0.001) and MD decreased (p=0.0001).ConclusionsBrain abnormalities in CKD are reversible and normalize with KT. Further studies are needed to understand the mechanisms underlying these brain abnormalities and to explore interventions to mitigate them even in patients who cannot be transplanted.Significance statementKidney disease is accompanied by brain structural and physiological abnormalities and increased risk of dementia and stroke. Renal replacement therapy with dialysis does not normalize these brain abnormalities. We evaluated these brain abnormalities before and after kidney transplantation and demonstrated that unlike dialysis, kidney transplantation normalizes cerebral blood flow, neurochemical concentrations and white matter integrity. These changes persist beyond initial post-transplantation period and thus cannot be attributed to peri-procedural interventions like steroids. These results indicate reversibility of brain abnormalities in kidney disease. Further studies are needed to understand the mechanisms underlying these abnormalities and explore interventions for prevention and mitigation in patients who cannot be transplanted.

scholarly journals Disconnectome Associated with Progressive Ischemic Periventricular White Matter Lesions

2019 ◽  
Author(s):  
Zhengjun Li ◽  
Sudipto Dolui ◽  
Mohamad Habes ◽  
Danielle S. Bassett ◽  
David Wolk ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Diffusion Tensor ◽  
Normal Aging ◽  
Elderly Subjects ◽  
Periventricular White Matter ◽  
Structural Connectome ◽  
Virtual Lesion ◽  
The Brain

AbstractPeriventricular white matter (PVWM) hyperintensities on T2-weighted MRI are ubiquitous in older adults and associated with dementia. Efforts to determine how PVWM lesions impact structural connectivity to impinge on brain function remain challenging in part because white matter tractography algorithms for diffusion tensor imaging (DTI) may lose fidelity in the presence of lesions. We used a “virtual lesion” approach to characterize the “disconnectome” associated with periventricular white matter (PVWM) lesions. We simulated progressive ischemic PVWM lesions using sub-threshold cerebral blood flow (CBF) masks derived from a previously published group-averaged map acquired from N=436 middle aged subjects in which the lowest CBF values were seen in PVWM and morphologically recapitulated the spatial pattern of PVWM hyperintensities seen in typical aging. We mimicked the age-dependent evolution of PVWM lesion burden by varying the threshold applied to the CBF map. We found that the optic radiations, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, corpus callosum, temporopontine tract and fornix were affected in early simulated PVWM lesion burdens, and that the connectivity of subcortical, cerebellar, and visual regions were significantly disrupted with increasing simulated PVWM lesion burdens. We also validated the use of virtual lesions to simulate the disconnectome due to WM hyperintensities in a cognitively normal elderly cohort (N=46) by evaluating correlations between structural and functional connectomes. The virtual lesion approach provides new insights into the spatial-temporal changes of the brain structural connectome under progressive PVWM burdens during normal aging.Significance StatementWe determined the disconnectomes caused by periventricular white matter (PVWM) lesions using the “virtual lesion” approach. We validated the approach using lesions, DTI and resting-state fMRI data from elderly subjects. We simulated disconnectome of progressive PVWM lesions using cerebral blood flow (CBF) masks in PVWM region with normative DTI data, which provides specificity for an ischemic mechanism and begins to address the possibility that connectivity may be affected by reduced CBF prior to the development of overt lesions on T2-weighted FLAIR MRI. The current study presented new insights into the spatial-temporal evolutions of the brain structural connectome under progressive PVWM burdens under normal aging.

scholarly journals On the Origins of the Cerebral IVIM Signal

2017 ◽  
Author(s):  
Hannah V. Hare ◽  
Robert Frost ◽  
James A. Meakin ◽  
Daniel P. Bulte
Keyword(s):  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
White Matter ◽  
High Resolution ◽  
Null Hypothesis ◽  
Quantitative Imaging ◽  
Arrival Times ◽  
Non Invasive ◽  
Blood Compartment ◽  
The Brain

AbstractPurposeIntravoxel incoherent motion (IVIM) has been proposed as a means of non-invasive MRI measurement of perfusion parameters such as blood flow and blood volume. Its main competitor in the brain is arterial spin labelling (ASL). In theory, IVIM should not suffer from some of the same limitations as ASL such as poor signal in white matter, and assumptions about arterial arrival times that may be violated in the presence of pathology.MethodsIn this study we aimed to test IVIM as a viable alternative to ASL for quantitative imaging of perfusion parameters in the brain. First, a direct comparison was performed between IVIM and multi-post label delay pseudo-continuous ASL; second, IVIM images were acquired with and without nulling cerebrospinal fluid; and finally, ultra-high resolution IVIM was performed to minimise partial voluming.ResultsIn all three tests, IVIM failed to disprove the null hypothesis, strongly suggesting that, at least within the brain, the technique does not measure perfusion parameters as proposed.ConclusionFurthermore, the results obtained suggest that the contrast visible in IVIM-derived images is primarily sensitive to cerebrospinal fluid, and not the microvascular blood compartment.

Abstract P65: Arterial Stiffness Relationship With Periventricular and Deep White Matter Hyperintensities in a Middle-Aged Population

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Yousef Hannawi ◽  
Lisa R Yanek ◽  
Brian G Kral ◽  
Dhananjay Vaidya ◽  
Lewis C Becker ◽  
...  
Keyword(s):  
White Matter ◽  
Arterial Stiffness ◽  
Brain Mri ◽  
Age Distribution ◽  
Periventricular White Matter ◽  
Linear Regression Models ◽  
Middle Aged ◽  
Systemic Hemodynamic ◽  
Deep White Matter ◽  
Aged Population

Introduction and hypothesis: Periventricular white matter (PVWM) is perfused by perforators originating from the proximal large caliber cerebral arteries with direct transmission of systemic hemodynamic changes as compared to the deep white matter (DWM) that is perfused by distal perforators with dampened transmission. We hypothesized that PVWM hyperintensities (PVWMH) are more strongly associated with the systemic vascular properties representing arterial stiffness (AS) due to vascular aging and hypertension compared to DWM hyperintensities (DWMH). Methods: Apparently healthy first degree relatives of subjects with coronary artery disease who had brain MRI as participants in GeneSTAR were selected. PVWMH and DWMH volumes were computed by an automated analysis software. Arterial stiffness indicators included peak systolic blood pressure during treadmill test, pulse pressure (PP), brachial artery (BA) diameter, carotid distensibility index, and diastolic dysfunction estimated by filling and systolic emptying rates (SER) on sestamibi cardiac scan. Statistical analysis was completed using unadjusted and age-adjusted linear regression models in the cohort that was divided into 4 quartiles based on age distribution (1 st : 29-43, 2 nd : 44-51, 3 rd : 52-59, 4 th : 60-74). Results: 782 participants were included (age 51.05±10.6 years, 58.4% female, 39% African American, PVWMH volume 1977.01±5195.81 ml and DWMH volume 625.93±1108.37 ml). In the unadjusted analysis, PVWMH showed association with PP in the 1 st and 3 rd age quartiles (p= 0.02 and 0.03, respectively) and SER in the 2 nd and 4 th age quartiles (p=0.04 and 0.03). This relationship remained significant in the adjusted analysis for SER (p=0.047, and 0.032, respectively) and in the 1 st age quartile for PP (P=0.02). DWMH relationship with BA diameter was significant in the 2 nd age quartile in the unadjusted and adjusted models (P=0.011, and 0.02, respectively). DWMH was also associated with ratio of cardiac filling/SER (P=0.039 and 0.047) in the 1 st age quartile. Conclusions: In this exploratory analysis, AS measures show different relationships to PVWMH and DWMH across age groups in middle-aged population suggesting a potential mechanistic role of AS in WMH pathology.

scholarly journals MRI differences between MOG antibody disease and AQP4 NMOSD

2020 ◽  
Vol 26 (14) ◽  
pp. 1854-1865 ◽  
Author(s):  
Sara Salama ◽  
Majid Khan ◽  
Amirali Shanechi ◽  
Michael Levy ◽  
Izlem Izbudak
Keyword(s):  
Spinal Cord ◽  
White Matter ◽  
Area Postrema ◽  
Brain Mri ◽  
White Matter Lesions ◽  
Mri Findings ◽  
Mri Features ◽  
Clinical Presentations ◽  
The Brain ◽  
Aqp4 Antibody

Background: MOG antibody and AQP4 antibody seropositive diseases are immunologically distinct subtypes of neuromyelitis optica spectrum disorders (NMOSD) with similar clinical presentations. MRI findings can be instrumental in distinguishing MOG antibody disease from AQP4 antibody NMOSD. Objectives: The aim of this study is to characterize the neuroradiological differences between MOG antibody disease and AQP4 antibody NMOSD with the aim to distinguish between the two entities. Methods: This is a retrospective study of 26 MOG and 25 AQP4 seropositive patients in which MRI features of the brain, spinal cord, and orbit were compared. Results: The majority of the abnormal findings in the MOG cohort were located on orbital MRIs, while spinal cord magnetic resonance (MR) abnormalities were more common in the AQP4 cohort. Brain abnormalities showed some overlap, but cortical gray/juxtacortical white matter involvement was distinct to MOG patients, while area postrema involvement was a rare feature. Conclusion: Cortical gray/juxtacortical white matter lesions on brain MRI might help distinguish MOG antibody disease from AQP4-positive NMOSD. These findings could be of value in distinguishing the two entities as early as the first presentation.

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