Multifactorial analysis of risk factors for foot ulcers in patients with neurovascular complications of diabetes.

Background: Diabetic foot ulcers (DFU) are a major complication associated with significant morbidity and mortality. While numerous studies have investigated risk factors for these ulcers in general, few have focused specifically on patients with Neurovascular Complications of Diabetes. This study aimed to evaluate the prevalence and risk factors for DFU in this specific population. Methods: We analyzed data from the National Institutes of Health (NIS) database for the years 2017-2019, involving a cohort of 161,834 patients aged over 18 who were diagnosed with neurovascular complications of diabetes. Demographic characteristics (age, gender, ethnicity), hospital characteristics, comorbidities, and other relevant data were included for analysis. A binary logistic regression model was generated to identify independent risk factors for DFU. Results: The prevalence of DFU among patients with neurovascular complications of diabetes was 29.4% during the period from 2017 to 2019. Compared to patients without DFU, those with DFU had longer hospitalization times and higher costs. The multiple regression analysis revealed that Iron-deficiency anemia (OR, 1.10; 95% CI, 1.01-1.11; P=0.019), Hypertension (OR, 1.07; 95% CI, 1.03-1.11; P=0.001), Obesity (OR, 1.08; 95% CI, 1.06-1.11; P<0.001), Peripheral vascular disorders (PVD) (OR, 1.69; 95% CI, 1.65-1.74; P<0.001), Osteomyelitis (OR, 7.10; 95% CI, 6.89-7.31; P<0.001), Tinea pedis (OR, 1.89; 95% CI, 1.59-2.26; P<0.001), Sepsis (OR, 1.24; 95% CI, 1.20-1.28; P<0.001), and onychomycosis (OR, 1.26; 95% CI, 1.13-1.42; P<0.001) were independent predictors for DFU in this population. Conclusion: The study found a high prevalence of DFU in patients with neurovascular complications of diabetes. Identifying and addressing risk factors such as deficiency anemia, hypertension, obesity, PVD, infections, and foot conditions may contribute to reducing the prevalence of DFU in this vulnerable population.

Shining light on neurovascular disease.

Tortuosity and fragility of the intracranial vasculature have precluded the application of novel intravascular imaging modalities during the treatment of cerebrovascular pathologies. In other circulatory beds, these technologies have transformed clinical and therapeutic decision-making. A new report demonstrates the clinical use of high-resolution intravascular imaging in the human cerebrovasculature using neuro optical coherence tomography. This technology provides an unprecedented opportunity to examine the luminal dimensions of cerebrovascular disease. We expect that the neurointerventional community will rapidly adopt this technology-similar to wider adoptions by other vascular specialties-for both a better understanding of underlying disease and clarity of endovascular therapeutic safety and effectiveness.

Effect of singular value decomposition on removing injection variability in 2D quantitative angiography: An in silico and in vitro phantoms study.

BACKGROUND: Intraoperative 2D quantitative angiography (QA) for intracranial aneurysms (IAs) has accuracy challenges due to the variability of hand injections. Despite the success of singular value decomposition (SVD) algorithms in reducing biases in computed tomography perfusion (CTP), their application in 2D QA has not been extensively explored. This study seeks to bridge this gap by investigating the potential of SVD-based deconvolution methods in 2D QA, particularly in addressing the variability of injection durations. PURPOSE: Building on the identified limitations in QA, the study aims to adapt SVD-based deconvolution techniques from CTP to QA for IAs. This adaptation seeks to capitalize on the high temporal resolution of QA, despite its two-dimensional nature, to enhance the consistency and accuracy of hemodynamic parameter assessment. The goal is to develop a method that can reliably assess hemodynamic conditions in IAs, independent of injection variables, for improved neurovascular diagnostics. MATERIALS AND METHODS: The study included three internal carotid aneurysm (ICA) cases. Virtual angiograms were generated using computational fluid dynamics (CFD) for three physiologically relevant inlet velocities to simulate contrast media injection durations. Time-density curves (TDCs) were produced for both the inlet and aneurysm dome. Various SVD variants, including standard SVD (sSVD) with and without classical Tikhonov regularization, block-circulant SVD (bSVD), and oscillation index SVD (oSVD), were applied to virtual angiograms. The method was applied on virtual angiograms to recover the aneurysmal dome impulse response function (IRF) and extract flow related parameters such as Peak Height PHIRF, Area Under the Curve AUCIRF, and Mean transit time MTT. Next, correlations between QA parameters, injection duration, and inlet velocity were assessed for unconvolved and deconvolved data for all SVD methods. Additionally, we performed an in vitro study, to complement our in silico investigation. We generated a 2D DSA using a flow circuit design for a patient-specific internal carotid artery phantom. The DSA showcases factors like x-ray artifacts, noise, and patient motion. We evaluated QA parameters for the in vitro phantoms using different SVD variants and established correlations between QA parameters, injection duration, and velocity for unconvolved and deconvolved data. RESULTS: The different SVD algorithm variants showed strong correlations between flow and deconvolution-adjusted QA parameters. Furthermore, we found that SVD can effectively reduce QA parameter variability across various injection durations, enhancing the potential of QA analysis parameters in neurovascular disease diagnosis and treatment. CONCLUSION: Implementing SVD-based deconvolution techniques in QA analysis can enhance the precision and reliability of neurovascular diagnostics by effectively reducing the impact of injection duration on hemodynamic parameters.

[Reversible cerebral vasoconstriction syndrome : A rare cause of stroke]. / Reversibles zerebrales Vasokonstriktionssyndrom : Eine seltene Schlaganfallursache.

Reversible cerebral vasoconstriction syndrome (RCVS) is a complex and etiologically diverse neurovascular disorder that typically presents with severe thunderclap headaches (TCH) as the primary symptom, accompanied by reversible vasoconstriction of the cerebral arteries. The clinical course may include focal neurological deficits or epileptic seizures. There are two types: idiopathic RCVS and secondary RCVS, the latter triggered by various substances, medical interventions, or diseases. In clinical practice, various medical specialists may initially encounter this condition, underscoring the importance of accurate recognition and diagnosis of RCVS. The clinical course often appears monophasic and self-limiting, with recurrences reported in only 1.7% of cases annually. Complications such as cerebral hemorrhages and cerebral ischemia can lead to death in 5-10% of cases. This article utilizes a case study to explore RCVS, its complications, and the diagnostic procedures involved.

A Rare Case of Cervical Spinal Arteriovenous Malformation: A Case Report.

Arteriovenous malformation (AVM) is an abnormal connection of vasculature resulting in capillary bed bypassing and leading to neurological deterioration and high risk of bleeding. Intramedullary AVMs in the cervical spinal cord are rare and require precise diagnostics and treatment. We present a clinical case of recurrent AVMs in a 28-year-old Caucasian female with sudden and severe neck pain and variable neurological symptoms along with current diagnostic and treatment modalities. Conservative treatment was partially effective. MRI and DSA confirmed AVMs at C4 level with subsequent several endovascular treatment sessions at the age of 15 and 24 with mild neurological improvement. Afterwards the patient underwent rehabilitation with minor neurological improvement. This case highlights the clinical progression and treatment of AVMs along with showcasing current pathophysiology, classification, and imaging.

Behavioral impairments are linked to neuroinflammation in mice with Cerebral Cavernous Malformation disease.

Background: Cerebral Cavernous Malformations (CCMs) are neurovascular abnormalities in the central nervous system (CNS) caused by loss of function mutations in KRIT1 (CCM1), CCM2, or PDCD10 (CCM3) genes. One of the most common symptoms in CCM patients is associated with motor disability, weakness, seizures, stress, and anxiety, and the extent of the symptom or symptoms may be due to the location of the lesion within the CNS or whether multiple lesions are present. Previous studies have primarily focused on understanding the pathology of CCM using animal models. However, more research has yet to explore the potential impact of CCM lesions on behavioral deficits in animal models, including effects on short-term and long-term memory, motor coordination, and function. Methods: We used the accelerating RotaRod test to assess motor and coordination deficits. We also used the open field test to assess locomotor activity and pathology-related behavior and Pavlovian fear conditioning to assess short-and long-term memory deficits. Our behavioral studies were complemented by proteomics, histology, immunofluorescence, and imaging techniques. We found that neuroinflammation is crucial in behavioral deficits in male and female mice with neurovascular CCM lesions (Slco1c1-iCreERT2; Pdcd10 fl/fl ; Pdcd10 BECKO ). Results: Functional behavior tests in male and female Pdcd10 BECKO mice revealed that CCM lesions cause sudden motor coordination deficits associated with the manifestation of profound neuroinflammatory lesions. Our findings indicate that maturation of CCM lesions in Pdcd10 BECKO mice also experienced a significant change in short- and long-term memory compared to their littermate controls, Pdcd10 fl/fl mice. Proteomic experiments reveal that as CCM lesions mature, there is an increase in pathways associated with inflammation, coagulation, and angiogenesis, and a decrease in pathways associated with learning and plasticity. Therefore, our study shows that Pdcd10 BECKO mice display a wide range of behavioral deficits due to significant lesion formation in their central nervous system and that signaling pathways associated with neuroinflammation and learning impact behavioral outcomes. Conclusions: Our study found that CCM animal models exhibited behavioral impairments such as decreased motor coordination and amnesia. These impairments were associated with the maturation of CCM lesions that displayed a neuroinflammatory pattern.

The Epidemiological Burden of Neurovascular Pathology in Nigeria: A Systematic Review and Pooled Patient-Level Analysis.

OBJECTIVE: Vascular neurosurgery has developed significantly in Nigeria, but its burden and challenges remain unclear. This study systematically reviewed vascular neurosurgical literature from Nigeria. METHODS: Four research databases and gray literature sources were searched from 1962-2021. ROBINS-I tool was used to assess risk of bias. Descriptive, narrative, and statistical analyses were conducted on all variables. Where appropriate, paired t-tests and Chi-squared independence tests were used (α = 0.05). RESULTS: 56 articles were included and 3203 patients pooled for analysis. Risk of bias was moderate-high. Most articles were published over the last 20 years with retrospective cohort studies and case reports being the most common study designs. The cohort had a relatively even gender split and an average age of 49 years (±22). Cerebrovascular accidents accounted for over 85% of diagnoses, with most etiologies being traumatic. Headache and motor deficit were the most prevalent clinical features. X-ray and carotid angiography were the most commonly reported imaging modalities, closely followed by computed tomography (CT) and CT angiography. The top two radiological diagnoses were ischemic cerebrovascular disease and intracerebral hematoma. Aneurysmal clipping and hematoma evacuation were the most commonly reported treatment modalities. Outcome at last follow-up was favorable in 48%. The mortality rate was 6%. Post-treatment complications included chest infection and rebleeding. CONCLUSIONS: This study illustrates the epidemiological burden of neurovascular pathology (based on the available data in published literature) in Nigeria, and raises awareness amongst service providers and researchers of the attendant challenges and epochal trends seen within vascular neurosurgery in Nigeria.

Uncommon optic nerve arteriovenous malformation: A case report and literature review.

BACKGROUND: The rapid progress in imaging techniques has led to an upsurge in the incidence of optic nerve arteriovenous malformations (AVMs) diagnoses. Nevertheless, a comprehensive integration addressing their diagnostic and therapeutic attributes remains elusive. CASE DESCRIPTION AND THE LITERATURE REVIEW: In this report, we present a case of optic nerve AVM in a patient who initially presented with progressive visual deterioration in the right eye. An orbital magnetic resonance imaging (MRI) scan revealed an abnormal signal intensity within the optic nerve region of the affected eye, and Computed Tomography Angiography (CTA) demonstrated the presence of a vascular malformation involving the optic nerve in the right eye. The diagnosis of optic nerve AVMs relies on Digital Subtraction Angiography (DSA). Given the challenging nature of surgical intervention, the patient opted for conservative management. Upon subsequent evaluation, no significant changes were observed in the patient's right visual acuity and visual field. Furthermore, a comprehensive literature review was conducted. CONCLUSIONS: In summary, the principal clinical presentations associated with optic nerve AVMs include a deterioration in both visual acuity and visual field. Angiography serves as the preferred diagnostic modality to confirm optic nerve AVMs. Microsurgical intervention or interventional embolization techniques may offer effective management approaches to address this complex condition.

Recommendations for detection, validation, and evaluation of RNA editing events in cardiovascular and neurological/neurodegenerative diseases.

RNA editing, a common and potentially highly functional form of RNA modification, encompasses two different RNA modifications, namely adenosine to inosine (A-to-I) and cytidine to uridine (C-to-U) editing. As inosines are interpreted as guanosines by the cellular machinery, both A-to-I and C-to-U editing change the nucleotide sequence of the RNA. Editing events in coding sequences have the potential to change the amino acid sequence of proteins, whereas editing events in noncoding RNAs can, for example, affect microRNA target binding. With advancing RNA sequencing technology, more RNA editing events are being discovered, studied, and reported. However, RNA editing events are still often overlooked or discarded as sequence read quality defects. With this position paper, we aim to provide guidelines and recommendations for the detection, validation, and follow-up experiments to study RNA editing, taking examples from the fields of cardiovascular and brain disease. We discuss all steps, from sample collection, storage, and preparation, to different strategies for RNA sequencing and editing-sensitive data analysis strategies, to validation and follow-up experiments, as well as potential pitfalls and gaps in the available technologies. This paper may be used as an experimental guideline for RNA editing studies in any disease context.

What is a Challenging Clot? : A DELPHI Consensus Statement from the CLOTS 7.0 Summit.

BACKGROUND: Predicting a challenging clot when performing mechanical thrombectomy in acute stroke can be difficult. One reason for this difficulty is a lack of agreement on how to precisely define these clots. We explored the opinions of stroke thrombectomy and clot research experts regarding challenging clots, defined as difficult to recanalize clots by endovascular approaches, and clot/patient features that may be indicative of such clots. METHODS: A modified DELPHI technique was used before and during the CLOTS 7.0 Summit, which included experts in thrombectomy and clot research from different specialties. The first round included open-ended questions and the second and final rounds each consisted of 30 closed-ended questions, 29 on various clinical and clot features, and 1 on number of passes before switching techniques. Consensus was defined as agreement ≥ 50%. Features with consensus and rated ≥ 3 out of 4 on the certainty scale were included in the definition of a challenging clot. RESULTS: Three DELPHI rounds were performed. Panelists achieved consensus on 16/30 questions, of which 8 were rated 3 or 4 on the certainty scale, namely white-colored clots (mean certainty score 3.1), calcified clots under histology (3.7) and imaging (3.7), stiff clots (3.0), sticky/adherent clots (3.1), hard clots (3.1), difficult to pass clots (3.1) and clots that are resistant to pulling (3.0). Most panelists considered switching endovascular treatment (EVT) techniques after 2-3 unsuccessful attempts. CONCLUSION: This DELPHI consensus identified 8 distinct features of a challenging clot. The varying degree of certainty amongst the panelists emphasizes the need for more pragmatic studies to enable accurate a priori identification of such occlusions prior to EVT.

Novel Aspects Targeting Platelets in Atherosclerotic Cardiovascular Disease-A Translational Perspective.

Platelets are important cellular targets in cardiovascular disease. Based on insights from basic science, translational approaches and clinical studies, a distinguished anti-platelet drug treatment regimen for cardiovascular patients could be established. Furthermore, platelets are increasingly considered as cells mediating effects "beyond thrombosis", including vascular inflammation, tissue remodeling and healing of vascular and tissue lesions. This review has its focus on the functions and interactions of platelets with potential translational and clinical relevance. The role of platelets for the development of atherosclerosis and therapeutic modalities for primary and secondary prevention of atherosclerotic disease are addressed. Furthermore, novel therapeutic options for inhibiting platelet function and the use of platelets in regenerative medicine are considered.

Metabolomic analysis of vascular cognitive impairment due to hepatocellular carcinoma.

Introduction: Screening for metabolically relevant differentially expressed genes (DEGs) shared by hepatocellular carcinoma (HCC) and vascular cognitive impairment (VCI) to explore the possible mechanisms of HCC-induced VCI. Methods: Based on metabolomic and gene expression data for HCC and VCI, 14 genes were identified as being associated with changes in HCC metabolites, and 71 genes were associated with changes in VCI metabolites. Multi-omics analysis was used to screen 360 DEGs associated with HCC metabolism and 63 DEGs associated with VCI metabolism. Results: According to the Cancer Genome Atlas (TCGA) database, 882 HCC-associated DEGs were identified and 343 VCI-associated DEGs were identified. Eight genes were found at the intersection of these two gene sets: NNMT, PHGDH, NR1I2, CYP2J2, PON1, APOC2, CCL2, and SOCS3. The HCC metabolomics prognostic model was constructed and proved to have a good prognostic effect. The HCC metabolomics prognostic model was constructed and proved to have a good prognostic effect. Following principal component analyses (PCA), functional enrichment analyses, immune function analyses, and TMB analyses, these eight DEGs were identified as possibly affecting HCC-induced VCI and the immune microenvironment. As well as gene expression and gene set enrichment analyses (GSEA), a potential drug screen was conducted to investigate the possible mechanisms involved in HCC-induced VCI. The drug screening revealed the potential clinical efficacy of A-443654, A-770041, AP-24534, BI-2536, BMS- 509744, CGP-60474, and CGP-082996. Conclusion: HCC-associated metabolic DEGs may influence the development of VCI in HCC patients.

An analysis of neurovascular disease markers in the hippocampus of Tupaia chinensis at different growth stages.

Introduction: It is considered that Tupaia chinensis can replace laboratory primates in the study of nervous system diseases. To date, however, protein expression in the brain of Tupaia chinensis has not been fully understood. Method: Three age groups of T. chinensis-15 days, 3 months and 1.5 years-were selected to study their hippocampal protein expression profiles. Results: A significant difference was observed between the 15-day group and the other two age groups, where as there were no significant differences between the 3-month and 1.5-year age groups. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that differentially expressed proteins could be enriched in several pathways related to neurovascular diseases, such as metabolic pathways for Alzheimer's disease (AD), Huntington's disease, Parkinson's disease, and other diseases. The KEGG enrichment also showed that relevant protein involved in oxidative phosphorylation in the hippocampus of T. chinensis for 15days were downregulated, and ribosomal proteins (RPs) were upregulated, compared to those in the hippocampus of the other two age groups. Discussion: It was suggested that when the hippocampus of T. chinensis developed from day 15 to 3 months, the expression of oxidatively phosphorylated proteins and RPs would vary over time. Meanwhile, the hippocamppal protein expression profile of T. chinensis after 3 months had become stable. Moreover, the study underlines that, during the early development of the hippocampus of T. chinensis, energy demand increases while protein synthesis decreases. The mitochondria of T. chinensis changes with age, and the oxidative phosphorylation metabolic pathway of mitochondria is closely related to neurovascular diseases, such as stroke and cerebral ischemia.

From 2D to 4D Phase-Contrast MRI in the Neurovascular System: Will It Be a Quantum Jump or a Fancy Decoration?

Considering the crosstalk between the flow and vessel wall, hemodynamic assessment of the neurovascular system may offer a well-integrated solution for both diagnosis and management by adding prognostic significance to the standard CT/MR angiography. 4D flow MRI or time-resolved 3D velocity-encoded phase-contrast MRI has long been promising for the hemodynamic evaluation of the great vessels, but challenged in clinical studies for assessing intracranial vessels with small diameter due to long scan times and low spatiotemporal resolution. Current accelerated MRI techniques, including parallel imaging with compressed sensing and radial k-space undersampling acquisitions, have decreased scan times dramatically while preserving spatial resolution. 4D flow MRI visualized and measured 3D complex flow of neurovascular diseases such as aneurysm, arteriovenous shunts, and atherosclerotic stenosis using parameters including flow volume, velocity vector, pressure gradients, and wall shear stress. In addition to the noninvasiveness of the phase contrast technique and retrospective flow measurement through the wanted windows of the analysis plane, 4D flow MRI has shown several advantages over Doppler ultrasound or computational fluid dynamics. The evaluation of the flow status and vessel wall can be performed simultaneously in the same imaging modality. This article is an overview of the recent advances in neurovascular 4D flow MRI techniques and their potential clinical applications in neurovascular disease. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Prevalence of cerebral small vessel disease in a Fabry disease cohort.

OBJECTIVE: To characterize the prevalence of brain ischemia and cerebral small vessel disease in a cohort of patients with Fabry disease (FD) seen at an academic medical center. BACKGROUND: FD is an inherited X-linked lysosomal storage disorder with central nervous system involvement. Limited data are available in the literature on the cerebrovascular neuroimaging findings in FD, and the reported prevalence of stroke symptoms and cerebral small vessel disease has varied widely. DESIGN/METHODS: Brain MRI was performed in 21 patients with FD followed at University of California Irvine Medical Center. Stroke symptoms were assessed and quantification of cerebral microvascular disease was performed using small vessel disease (SVD) score. Lacunes and deep white matter hyperintensities were scored on a four-point scale of 0 (absent) and 1-3 to account for increasing severity; microbleeds were scored 0 (absent) or 1 (present). The total SVD score is the sum of the three components and ranges from 0 to 7. RESULTS: Nearly 43% (9/21) of our FD cohort (aged 32-81 years, mean = 50) had a SVD score of one or higher, all of whom were aged 50 or more years. The most common MRI-defined SVD was white matter hyperintensities (9/9, 100%), followed by microbleeds (6/9, 66%), and lacunes (3/9, 33%). The three patients with previous strokes had some of the highest SVD scores reported in the cohort (scores 3-5). CONCLUSIONS: In this cohort, the prevalence of SVD (43%) was three times higher than prevalence of stroke symptoms. SVD score was highest in the those who had experienced a stroke. These findings emphasize the importance of routine MRI screening of patients with FD in order to identify and treat high risk patients.

Assessment of patients with a suspected cardioembolic ischemic stroke. A national consensus statement.

OBJECTIVES: Several cardiovascular, structural, and functional abnormalities have been considered as potential causes of cardioembolic ischemic strokes. Beyond atrial fibrillation, other sources of embolism clearly exist and may warrant urgent action, but they are only a minor part of the many stroke mechanisms and strokes that seem to be of embolic origin remain without a determined source. The associations between stroke and findings like atrial fibrillation, valve calcification, or heart failure are confounded by co-existing risk factors for atherosclerosis and vascular disease. In addition, a patent foramen ovale which is a common abnormality in the general population is mostly an innocent bystander in patients with ischemic stroke. For these reasons, experts from the national Danish societies of cardiology, neurology, stroke, and neuroradiology sought to develop a consensus document to provide national recommendations on how to manage patients with a suspected cardioembolic stroke. Design: Comprehensive literature search and analyses were done by a panel of experts and presented at a consensus meeting. Evidence supporting each subject was vetted by open discussion and statements were adjusted thereafter. Results: The most common sources of embolic stroke were identified, and the statement provides advise on how neurologist can identify cases that need referral, and what is expected by the cardiologist. Conclusions: A primary neurological and neuroradiological assessment is mandatory and neurovascular specialists should manage the initiation of secondary prophylactic treatment. If a cardioembolic stroke is suspected, a dedicated cardiologist experienced in the management of cardioembolism should provide a tailored clinical and echocardiographic assessment.

Distribution of variations in anatomy of the circle of Willis: results of a cadaveric study of the Malawian population and review of literature.

INTRODUCTION: the circle of Willis is an anatomical structure of clinical importance particularly in the evaluation of neurovascular diseases. Individuals show considerable variations in the anatomical configuration of the circle of Willis. A cross-sectional study was conducted to determine the distribution of morphological variations of the circle of Willis in Malawians and compare with other ethnic groups. METHODS: brains were collected from twenty-four recently deceased black Malawians during autopsy at Queen Elizabeth Central Hospital, a referral teaching hospital in Blantyre, Malawi and fixed in 10% buffered formalin. Digital images of the interpeduncular region (exposing the circle of Willis) were taken with an 18.4 megapixels camera from the base of the brain. Whole-circle and segmental parameters of the circle of Willis were assessed using the Osiris computer programme and classified based on a 22-type classification scheme. RESULTS: the following morphological variations were observed: hypoplasia, aplasia, asymmetry and accessory vessels. Typical circle of Willis was seen in 26% of the cases. Only six of the original twenty-two types were observed. Consistent with most previous studies, types 1, 3, 4, 6, 8 and 9 were common while types 10-22 were rare. Three variants not previously described in the original scheme (unilateral PcoA aplasia, AcoA duplication, and PcoA aplasia with contralateral PcoA hypoplasia) were observed in this study. CONCLUSION: anatomical variations of the circle of Willis in Malawians seem to be distributed in similar frequencies and patterns as in other more-diverse populations. Circle of Willis variants with potential predilection for atherogenesis and aneurysm formation exist in the Malawian population. These should be considered in clinical practice.

Intracranial Hemorrhage in Patients with Coronavirus Disease 2019 (COVID-19): A Case Series.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is an ongoing public health emergency. While most cases end in asymptomatic or minor illness, there is growing evidence that some COVID-19 infections result in nonconventional dire consequences. We sought to describe the characteristics of patients with intracranial hemorrhage who were infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, with the existing literature, we raise the idea of a possible association between SARS-CoV-2 infection and intracranial hemorrhage and propose possible pathophysiological mechanisms connecting the two. METHODS: We retrospectively collected and analyzed intracranial hemorrhage cases who were also positive for SARS-CoV-2 from 4 tertiary-care cerebrovascular centers. RESULTS: We identified a total of 19 patients consisting of 11 males (58%) and 8 females (42%). Mean age was 52.2, with 95% younger than 75 years of age. With respect to COVID-19 illness, 50% had mild-to-moderate disease, 21% had severe disease, and 20% had critical disease requiring intubation. Of the 19 cases, 12 patients had intraparenchymal hemorrhage (63%), 6 had subarachnoid hemorrhage (32%), and 1 patient had a subdural hematoma (5%). A total of 43% had an intracerebral hemorrhage score of 0-2 and 57% a score of 3-6. Modified Rankin Scale cores at discharge were 0-2 in 23% and 3-6 in 77%. The mortality rate was 59%. CONCLUSIONS: Our series sheds light on a distinct pattern of intracerebral hemorrhage in COVID-19-positive cases compared with typical non-COVID-19 cases, namely the severity of hemorrhage, high mortality rate, and the young age of patients. Further research is warranted to delineate a potential association between SARS-CoV-2 infection and intracranial hemorrhage.

Evaluation of methods to derive blood flow velocity from 1000 fps high-speed angiographic sequences (HSA) using optical flow (OF) and computational fluid dynamics (CFD).

Digital Subtraction Angiography (DSA) is considered the gold standard for imaging and guiding treatment of neurovascular lesions, such as cerebral aneurysms and carotid stenoses. Though DSA can show high-resolution morphology, it remains difficult to extract temporal physiological information, because higher frame-rates are necessary to accurately quantify neurovascular flow details. Recent advances in photon-counting detector technology have led us to develop High-Speed Angiography (HSA), where X-ray images are acquired at 1000 fps for more accurate visualization and quantification of blood flow. Blood flow was imaged using HSA under constant flow conditions within various 3D printed patient-specific phantoms. Blood velocity was quantified using an open source Optical Flow algorithm, OpenOpticalFlow, to perform velocity estimation based on the spatio-temporal intensity changes of iodinated contrast wavefronts. The results of these algorithms are then compared with Computational Fluid Dynamics (CFD) simulations, using the same inlet boundary conditions and model geometries. The performance of these algorithms at lower temporal resolution was then also assessed by simulating lower frame rates from the acquired 1000 fps data. It is important to ascertain the hemodynamic effect of abnormal neurovascular conditions, as well as their effect on treatment of such conditions during the actual clinical interventional procedure. While theoretical CFD results requiring considerable computer capability are delayed for hours or more, it is expected that clinical results from multiple HSA sequences will be available almost immediately while the patient is still under treatment, and even right after flow conditions are changed beneficially by the intervention.

Characterization of velocity patterns produced by pulsatile and constant flows using 1000 fps high-speed angiography (HSA).

In order to accurately quantify rapidly changing blood flow velocities, as typically seen in the neurovasculature, high temporal resolution is necessary. Current methods to extract velocity data from angiographic image sequences are generally limited to 30 fps or less. High-speed angiography (HSA) with a maximal frame rate of 1000 fps can be used to evaluate time-dependent flow details normally averaged out with lower frame rates. For new HSA image sequences, two different quantitative methods were utilized to extract high-temporal resolution velocity changes: X-Ray Particle Image Velocimetry (X-PIV) and optical flow (OF). A variety of flow conditions were examined in a range of patient-specific 3D-printed phantoms. Both pulsatile and constant flow settings were investigated. X-PIV was performed using radiopaque sub-millimeter microspheres, which were tracked throughout the image sequence to provide accurate, but limited sampling of the velocity field within the 3D-printed models. Also, an open source optical flow algorithm, OpenOpticalFlow, was used to perform velocity estimation based on the spatio-temporal intensity changes of iodinated contrast wavefronts. Periodic changes in velocity within each phantom ROI can be illustrated throughout the pulsatile cycle capture by the high-speed detector. In the constant flow sequences, changes in velocity across the phantom geometry can be seen. The ability to accurately measure detailed velocity distributions and velocity changes throughout various flow conditions at high temporal resolution enables further insight into the evaluation and treatment of neurovascular disease states.