Cerebral Venous Thrombosis Research Articles

Early Versus Late Initiation of Endovascular Therapy in Patients with Severe Cerebral Venous Sinus Thrombosis.

Endovascular therapy (EVT) for severe cerebral venous sinus thrombosis (CVST) is controversial in terms of indication and clinical benefit. The impact of delay of EVT on functional recovery is unclear. This study aimed to investigate the effect of early versus late initiation of EVT in severe CVST. From prospective EVT and CVST registries, patients with CVST diagnosed between January 2010 and December 2022 were retrospectively identified for this multicenter collaboration. EVT was considered in severe CVST with features prone to a poor prognosis. We compared early (< 24h) with late (> 24h) initiation of EVT after the presentation in the emergency department and subsequent CVST diagnosis. Outcome parameters included functional independence (modified Rankin Scale [mRS] score 0-2) at 90days, mRS score at discharge, in-hospital mortality, and mortality at 3months. Of 363 patients with CVST, 45 (12.4%; 31 [early EVT] vs. 14 [late EVT]) were included in this study. We found a higher proportion of patients with functional independence at 3months among early versus late EVT (66.7% vs. 27.3%; odds ratio [OR] 5.3; 95% confidence interval 1.02-25; p = 0.036). In multivariate logistic regression, late EVT was inversely correlated with functional independence (OR 0.17 [0.04-0.83]; p = 0.011). The mortality rate was 16.7% versus 36.4% (mRS 6 at 3months, OR 0.34, 95% confidence interval 0.07-1.75; p = 0.217) at 90days for early versus late EVT. We observed a higher rate of functional independence in patients with early EVT. These preliminary findings must be confirmed in subsequent randomized controlled trials evaluating a "time-is-brain" paradigm for EVT in CVST.

The effect of SARS-CoV-2 on the incidence of post-operative venous sinus thrombosis following skull base procedures.

Sinus thrombosis is a common post-operative finding after posterior fossa surgery performed in the vicinity of the dural venous sinuses. The SARS-CoV-2 virus has been shown to confer an increased risk of venous thromboembolic events owing to eliciting a hyper-inflammatory and pro-thrombotic state. In this study, we examine the incidence of post-operative venous sinus thrombosis in patients undergoing peri-sigmoid posterior fossa surgery in the pre- and post-COVID era and investigate whether COVID infection confers an increased risk of sinus thrombosis. A retrospective review of a single institution case series of patients underwent peri-sigmoid surgery (retrosigmoid, translabyrinthine, or far lateral) approach. Relevant clinical variables were investigated that may confer an increased risk of sinus thrombosis. A total of 311 patients (178 in the pre-COVID era, and 133 operated on after the pandemic began in March 2020) are included in the study. The composite incidence of sinus thrombosis seen on post-operative imaging was 7.8%. The incidence of sinus thrombosis in the pre-COVID cohort was N = 12 patients (6.7%) versus N = 12 (9%) in the post-COVID cohort (p = 0.46). A history of COVID infection was not shown to confer an increased risk of post-operative sinus thrombosis (OR: 0.61; 95% CI: 0.08-4.79, p = 0.64). Only a small number of patients (N = 7, 2.3%) required either medical or surgical intervention for post-operative sinus thrombosis. The overall incidence of post-operative sinus thrombosis is similar in the pre- and post-COVID era. The findings of this study suggest that COVID infection is not associated with a higher risk of venous sinus thrombosis.

Prevalence, clinical presentation, and treatment-management of cerebral venous thrombosis associated with spontaneous intracranial hypotension: A combined case-series and systematic literature review approach.

Cerebral venous thrombosis (CVT) is a rare complication of spontaneous intracranial hypotension (SIH). Therefore, its correct diagnosis and the corresponding optimal treatment-management identification remains challenging. Over the last 10 years, 300 patients received a definite SIH diagnosis at our stroke center. Through thorough review of the database, we identified all patients with SIH-related CVT. In addition, we performed a systematic literature review including all publications on SIH-related CVT. Five out of our 300 SIH patients showed CVT (F/M:2/3, mean age: 51.8 ± 15.7). Through the literature search, 72 additional cases were identified. Overall, the prevalence was 1.3% and main clinical presentations were orthostatic headache, nausea, and vomiting. The CVT was predominantly located at the superior sagittal sinus. Treatment strategies included anticoagulants (ACs) (43%), epidural blood patch (EBP) (19.4%), and combined AC + EBP (33.3%). In our cohort, all but one patient received combined EBP and AC. The mean clinical and radiological follow-up were 2 years and 1.5 years, respectively. Complete clinical recovery was reported in 96% of the cases, whereas 56% showed complete radiological CVT resolution. Among patients without radiological resolution (26.4%), 57% received AC-only, while 43% received combined AC + EBP. Of our five cases, all but one patient received combined AC + EBP. The overall prevalence of SIH-related CVT was 1.3%. AC and combined AC + EBP were the most used treatment-management strategies. CVT resolution was more commonly achieved after the combined strategy. Overall, the rate of complete clinical recovery was 96%.

Hydrogel-Based Therapies for Ischemic and Hemorrhagic Stroke: A Comprehensive Review.

Stroke remains the second leading cause of death and a major cause of disability worldwide, significantly impacting individuals, families, and healthcare systems. This neurological emergency can be triggered by ischemic events, including small vessel arteriolosclerosis, cardioembolism, and large artery atherothromboembolism, as well as hemorrhagic incidents resulting from macrovascular lesions, venous sinus thrombosis, or vascular malformations, leading to significant neuronal damage. The resultant motor impairment, cognitive dysfunction, and emotional disturbances underscore the urgent need for effective therapeutic interventions. Recent advancements in biomaterials, particularly hydrogels, offer promising new avenues for stroke management. Hydrogels, composed of three-dimensional networks of hydrophilic polymers, are notable for their ability to absorb and retain substantial amounts of water. Commonly used polymers in hydrogel formulations include natural polymers like alginate, chitosan, and collagen, as well as synthetic polymers such as polyethylene glycol (PEG), polyvinyl alcohol (PVA), and polyacrylamide. Their customizable characteristics-such as their porosity, swelling behavior, mechanical strength, and degradation rates-make hydrogels ideal for biomedical applications, including drug delivery, cell delivery, tissue engineering, and the controlled release of therapeutic agents. This review comprehensively explores hydrogel-based approaches to both ischemic and hemorrhagic stroke therapy, elucidating the mechanisms by which hydrogels provide neuroprotection. It covers their application in drug delivery systems, their role in reducing inflammation and secondary injury, and their potential to support neurogenesis and angiogenesis. It also discusses current advancements in hydrogel technology and the significant challenges in translating these innovations from research into clinical practice. Additionally, it emphasizes the limited number of clinical trials utilizing hydrogel therapies for stroke and addresses the associated limitations and constraints, underscoring the need for further research in this field.

Study of Use of Dabigatran in Cerebral Venous Sinus Thrombosis.

Cerebral venous sinus thrombosis (CVST) is a challenging condition to diagnose and treat due to its diverse range of clinical presentations. The incidence of CVST is increasing, and although diagnostic techniques have improved, the mainstay of treatment is heparin followed by vitamin K antagonist (VKA), warfarinhas remained largely unchanged for the past three decades. However, new direct oral anticoagulants (NOACs) like dabigatran have been developed to address the limitations of VKA therapy. Magnetic resonance imaging (MRI) with magnetic resonance venography (MRV) is the current preferred diagnostic method for CVST due to its exceptional sensitivity and specificity. This prospective observational study was set out to investigate the efficacy and safety of dabigatran in treating cerebral venous sinus thrombosis. The study included 30 patients who reported regular intake of 150 mg dabigatran etexilate twice a day. Among the participants, headache was the most commonly reported symptom. The study found that patients treated with dabigatran experienced favorable outcomes, with all patients achieving re-canalization and reporting no major complications. These promising results suggest that dabigatran could be an effective treatment option for CVST cases. However, the study emphasizes the need for larger, multi-center studies to further validate these findings and improve the overall understanding of the condition and its treatment options.

Clinical observation of cerebral venous thrombosis and reversible vasoconstriction syndrome in a young patient

Despite the capabilities and availability of modern diagnostic methods, due to the low alertness of doctors, a number of cerebrovascular disorders are diagnosed late, which can lead to serious consequences, illness leading to disability and death in patients of working age. A clinical case of a young patient with recurrent cerebral venous thrombosis and reversible cerebral vasoconstriction syndrome is presented.

Lung cancer brain metastasis and hemorrhagic cerebral venous thrombosis: experiences and lessons

The incidence of lung cancer brain metastasis combined with hemorrhagic cerebral venous sinus thrombosis (CVST) is very rare, and the understanding and treatment experience of this case is insufficient. We reported a case of lung cancer brain metastasis accompanied by venous sinus thrombosis, and describe the diagnosis and treatment plan for colleagues to learn from experience and lessons.

Efficacy and safety of direct oral anticoagulants versus warfarin in the treatment of cerebral venous sinus thrombosis.

Given the evolving application and promising outcomes of direct oral anticoagulants (DOACs) in various thromboembolic conditions, we aimed to compare the efficacy and safety of DOACs with warfarin in the post-acute treatment of cerebral venous sinus thrombosis (CVST) using clinical and radiological parameters. A total of 140 CVST patients were enrolled, with 95 receiving warfarin and 45 receiving DOACs as post-acute treatment. Clinical and imaging parameters of the patients in follow-up visits were investigated, including the last modified Rankin Scale (mRS), venousthromboembolic events, CVST recurrence, mortality rate, recanalization status, and hemorrhagic events, to compare the efficacy and safety of treatment between the two groups. At baseline, patients' assessments using two prognostic scores, ISCVT-RS and IN-REvASC, revealed that there was no statistically significant difference in the distribution of prognostic risk categories between the warfarin and DOACs groups. Following acute therapy, patients in the warfarin and DOACs groups were followedup forthemedian of359 and325days, respectively. Analysis to compare the efficacy of warfarin and DOACs revealed no significant difference in last mRS scores, CVST recurrencerate, venousthromboembolic events, and recanalizationstatus between the two groups. Additionally, there was no statistically significant difference in the risk of hemorrhagic events between warfarin and DOACsgroups. Our findings show that DOACs have comparable safety and efficacy in the post-acute treatment of CVST patients; however, large-scalerandomized controlled trials are required to validate our findings.

The postulated role of brain pulsations and arachnoid membranes in cerebrospinal fluid circulation, ventriculomegaly and related CSF disorders

Hydrocephalus can be obstructive or communicating. In cases of communicating hydrocephalus, patients will typically have enlarged brain ventricles. It has long been thought that the reason for this is obstruction to the outflow of cerebrospinal fluid from the subarachnoid space, which also results in raised intracranial pressure (ICP). However, there are several clinical and anatomic observations that are not well explained by this idea. These are for example, the conditions of Normal pressure hydrocephalus (NPH) which has normal ICP but ventriculomegaly, and idiopathic intracranial hypertension (IIH) which has raised ICP but normal sized ventricles. This hypothesis states that the mechanism for raised ICP and large ventricles seen in communicating hydrocephalus (ventriculomegaly) are different and seeks to explain the cause of ventriculomegaly using illustrative examples. It also suggests explanations for why ventriculomegaly occurs in NPH, infectious or carcinomatous meningitis, but is absent in IIH, or dural venous sinus thrombosis. Based on operative neurosurgical observations it states that the arachnoid membranes in the basal cisterns serve as part of a directional CSF flow mechanism consisting of fluid diodes, or “Tesla valves” of arachnoid membrane, containing CSF that is propelled by brain pulsations from the point of exit from the 4th ventricle to its points of absorption. This hypothesis suggests explanations for the physiologic appearance of a near uniform subarachnoid space, as well as the occurrence of the syndrome of the trephined and external hydrocephalus seen following a decompressive craniectomy. Also suggested are avenues of further research testing with MRI phase contrast CSF flow studies, classification of anatomic and peri-operative observations and rationale for creation of novel experiments to test the hypothesis, and aid diagnosis and treatment of a number of cranial CSF disorders.

Acute Stroke in the Emergency Department: Profiles of Patients and Obstacles to Acute Intervention.

To build a demographic profile of patients presenting to the emergency department (ED) with stroke, determine the proportion who successfully undergo thrombolysis and active interventions, and study their outcomes up to discharge or death in the hospital. A sample size of 215 was calculated and patients were recruited consecutively on presentation to the ED after obtaining consent. Data was collected and they were followed up till the outcome. Data was tabulated and analyzed both as a whole and after further categorization into infarction, hemorrhagic stroke, and cerebral venous thrombosis (CVT). Mean and standard deviation were used for continuous variables and chi-square for categorical variables. A total of 216 patients were recruited, 156 (72%) male and 60 (28%) female. There were 135 (63%) ischemic strokes, 67 (31%) hemorrhagic, and 14 (6%) CVT. The mean age was 56.57 years (SD 14.22 years). A total of 12 patients (5.5%) presented within the 'golden hour' and 28 ischemic strokes presented within the thrombolysis window, of which nine were thrombolyzed. In total, 39 patients were intubated in the ED, of which 10 (7.41%) had ischemic strokes, 27 (40.3%) had hemorrhagic strokes and two(14.29%) had CVTs. There were 192 patients admitted to in-patient care, while 24 (11%) were discharged against medical advice. A further 14 patients were intubated during admission. Nine patients (13.43%) with hemorrhagic strokes underwent surgical decompression, five (7.46%) had an external ventricular drain (EVD) placed, six (8.96%) underwent aneurysm clipping, and two (2.99%) underwent aneurysm coiling. One case of CVT underwent surgical decompression. Stroke is a highly heterogeneous clinical entity with nuanced differences between the different subtypes. There appear to be significant obstacles regarding the early presentation of strokes to hospitals and the initiation of thrombolysis in the case of acute interventions.

Acute cerebral venous sinus thrombosis presenting in papilloedema: a case report

Background: Papilloedema has several aetiologies, including brain tumours, central nervous system inflammation, cerebral venous thrombosis, cerebral venous sinus thrombosis (CVST), and idiopathic intracranial hypertension. CVST is a rare condition and a form of stroke with an incidence of 5:1,000,000/year. Case presentation: A 23-year-old female developed impaired vision in her left eye, accompanied by headache, nausea, and vomiting, 5 weeks prior to hospitalization. Visual acuity in the left eye (OS) was 6/12, which improved to 6/9 on pinhole examination, and to 6/6 with S-0.50 and C-0.50 on the 180° axis. OS intraocular pressure (IOP) was 14 mmHg. Bilateral funduscopic examination revealed papilloedema, peripapillary venous tortuosity, and macular exudate. Both computerised tomography scan and magnetic resonance angiography examination detected superior sagittal sinus thrombosis. Conclusion: Acute CVST is a rare condition. A good prognosis depends on early diagnosis and prompt treatment.

Clinical Conundrum: Return to High Altitude After Cerebral Venous Sinus Thrombosis.

Luks, Andrew M., Thomas G. DeLoughery, Jeffrey H. Gertsch, and Suzy Stokes. Clinical conundrum: return to high altitude after cerebral venous sinus thrombosis. High Alt Med Biol. 00:00-00, 2024.

Correlation between Severity of Lung Disease in COVID-19 Infection and Acute CNS Abnormalities

Abstract Background Sever acute respiratory syndrome corona virus 2 (SARS-COV 2) began in Wuhan,China,in December 2019 and has rapidely spread around the world to become pandemic,as COVID-19 can produce pathologic changes in chest imaging,COVID-19 related brain imaging findings are also well known. Aim of the Work The aim of this current study is to correlate retrospectively between the severity of lung affection in patients with COVID-19 infections and development of acute CNS abnormalities. Patients and Methods This study is Retrospective study, the study was conducted at Ain Shams University Hospitals over a course of six months from march 2022 to September 2022 and the main source of data for this study was the archived CT and MRI imaging of the patients referred to the department of Radiology. Our inclusion criteria were patients that diagnosed with sever acute respiratory syndrome corona virus 2 infection with acute neurologic manifestation and available chest CT and brain imaging. The 5 lobes of the lungs were individually scored on a scale 0-5 (0 correspond to no involvement and 5 &amp;gt; 75% involvement),A CT lung severity score was determined as the sum of lung involvement,ranging from 0 (no involvement) to 25 (maximum involvement). Results A total 55 patients met the inclusion criteria,In attempt to describe and evaluate the brain and lung imaging correlation in patients with COVID-19, Compared to 20 patients without acute abnormal findings on neuroimaging,there were 35 patients with acute abnormal findings on neuroimaging and those patients were found to have significantly higher mean CT lung severity score (p &amp;lt; 0.0001) and they are more likely to present with ischemic stroke (14, 40%), A threshold of CT lung severity score &amp;gt; 18 was found to be 97% sensitive and 90% specific for acute abnormal findings on neuroimaging, the neuroimaging hallmark of these patients were acute ischemic infarcts (40%),invasive fungal sinusitis (22.9.%), Isolated cavernous sinus thrombosis,PRES,and vasculitis (each one 8.6%),cerebral venous sinus thrombosis other than cavernous sinus (5.7%),cerebritis and abnormal white matter signal (each one 2.8%).The predominant CT chest findings were peripheral ground -glass opacities with or with out consolidation. Conclusion The CT lung severity score may be predictive of acute abnormalities on neuroimaging in patients with COVID-19 with neurologic manifestation. This can be used as predictive tool in patients management to improve clinical outcome.

Cerebral Small Vessel Disease in Children and Adolescents with Type 1 Diabetes Presenting with Diabetic Ketoacidosis during COVID-19 Era

Abstract Aim Cerebrovascular insult (CVI) is a known and significant morbidity of diabetic ketoacidosis (DKA); yet, its prevalence is underestimated. Untreated cerebral hypoperfusion in DKA may lead to cerebral injury, arterial ischemic stroke, cerebral venous thrombosis, and hemorrhagic stroke. This study assesses the cerebral perfusion status among children and adolescents with DKA during and after the resolution of DKA. Methodology Forty children and adolescents with type 1 diabetes mellitus (T1DM) presenting with DKA were assessed for severity of DKA, diabetes-duration, insulin therapy, Rappaport coma/ Near coma scale, Rancho los amigos levels of cognitive functioning scale, glycated-hemoglobin (HbA1c), D-dimer, INR and brain magnetic resonance imaging (MRI) during DKA and repeated neuro cognitive scoring, laboratory and MRI after resolution of the DKA. Results The mean age of the children and adolescents with T1DM presenting with DKA was 11.40 ± 2.82 years; their median diabetes-duration was 3 year; their mean HbA1c was 13.54 ± 2%. There was significant increase in platelet (P = 0.005), D-dimer (P &amp;lt; 0.001), Creatinine (P &amp;lt; 0.001) and Pulse wave velocity (P = 0.004) during attack of DKA while there was significance decrease in Apparent diffusion coefficient (P &amp;lt; 0.001). There was 30% of children and adolescents with T1DM had ischemic MRI changes during DKA. In children and adolescent with ischemic changes there was significant increase in severity of DKA (P = 0.003), HbA1c (P = 0.016), INR (P = 0.002), D-dimer (P &amp;lt; 0.001), Creatinine (P = 0.003). Conclusion Significant cerebral hypoperfusion occur during the DKA which is correlated with the DKA severity and D-dimer levels.

Machine learning-based Cerebral Venous Thrombosis diagnosis with clinical data

ObjectivesCerebral Venous Thrombosis (CVT) poses diagnostic challenges due to the variability in disease course and symptoms. The prognosis of CVT relies on early diagnosis. Our study focuses on developing a machine learning-based screening algorithm using clinical data from a large neurology referral center in southern Iran. MethodsThe Iran Cerebral Venous Thrombosis Registry (ICVTR code: 9001013381) provided data on 382 CVT cases from Namazi Hospital. The control group comprised of adult headache patients without CVT as confirmed by neuroimaging and was retrospectively selected from those admitted to the same hospital. We collected 60 clinical and demographic features for model development and validation. Our modeling pipeline involved imputing missing values and evaluating four machine learning algorithms: generalized linear model, random forest, support vector machine, and extreme gradient boosting. ResultsA total of 314 CVT cases and 575 controls were included. The highest AUROC was reached when imputation was used to estimate missing values for all the variables, combined with the support vector machine model (AUROC = 0.910, Recall = 0.73, Precision = 0.88). The best recall was achieved also by the support vector machine model when only variables with less than 50 % missing rate were included (AUROC = 0.887, Recall = 0.77, Precision = 0.86). The random forest model yielded the best precision by using variables with less than 50 % missing rate (AUROC = 0.882, Recall = 0.61, Precision = 0.94). ConclusionThe application of machine learning techniques using clinical data showed promising results in accurately diagnosing CVT within our study population. This approach offers a valuable complementary assistive tool or an alternative to resource-intensive imaging methods.

VASCULAR PARKINSONISM WITH EARLY COGNITIVE IMPAIRMENT: A CASE REPORT AND LITERATURE REVIEW

Cerebral venous sinus thrombosis (CVST) is an uncommon condition of cerebral venous sinus thrombosis with a varied clinical presentation that can be diagnostically challenging. Intravenous heparin is the optimal immediate anticoagulant according to the European Academy of Neurology (EAN) guideline 2017. This report aims to describe highly suspicious CVST clinical features and suggest a diagnostic algorithm based on two cases of CVST found in our center. The first case is a 52-year-old man who presented with serial seizures preceded by subacute headache and diparesis. Non-contrast head CT (NCCT) showed multifocal haemorrhages and cord signs. The second case is a 19-year-old woman who presented with slowly decreased consciousness, headache, and a history of upper respiratory infection. Diffuse cerebral edema was revealed in NCCT. Both of these patients had thrombosis in superior sagittal sinus, right transverse, and sigmoid sinus. Heparinization was conducted and continued with rivaroxaban with a good response. CVST is rare case and often unrecognized; since it has serious complications, early diagnosis and treatment improve prognosis and survival.

Prediction of Long-Term Poor Clinical Outcomes in Cerebral Venous Thrombosis Using Neural Networks Model: The BEAST Study.

Risk prediction models are commonly performed with logistic regression analysis but are limited by skewed datasets. We utilised neural networks (NNs) model to identify independent predictors of poor outcomes in cerebral venous thrombosis (CVT) due to the limitations of logistic regression (LR) analysis with complex datasets. We evaluated 1309 adult CVT patients from the prospective BEAST (Biorepository to Establish the Aetiology of Sinovenous Thrombosis) study. The area under the receiver operating characteristic (AUROC) curve confirmed the goodness-of-fit of prediction models. The normalised importance (NI) of the NNs determines the significance of independent predictors. The stepwise logistic regression model found thrombolysis (OR 32.1; 95% CI 3.6-287.0; P=0.002), craniotomy (OR 6.9; 95% CI 1.3-36.8; P=0.02), and cerebral haemorrhage (OR 4.5; 95% CI 1.3-15.4; P=0.01) as predictors of poor clinical outcome with the AUROC of 0.71. Conversely, the NNs model identified major independent predictors of long-term poor clinical outcomes as cerebral haemorrhage (NI 100%) and thrombolysis (NI 98%), as well as trivial predictors of age (NI 2.8%) and altered mental status (NI 3.5%). The accuracy of the NNs model was 95.1% and 94.1% for self-learned randomly selected training and testing samples with an AUROC of 0.82. Positive and negative predictive values for poor outcomes were 13.2% and 97.1% for the LR model, compared with the NNs model of 18.8% and 98.7%, respectively. Cerebral haemorrhage and thrombolysis was a strong independent predictor, whereas age merely impacts the long-term poor clinical outcome in adult CVT. Integrating unorthodox neural networks risk prediction model can improve decision-making as it outperforms conventional logistic regression with complex datasets.

Generative Pre-trained Transformer for Pediatric Stroke Research: A Pilot Study

BackgroundPediatric stroke is an important cause of morbidity in children. Although research can be challenging, large amounts of data have been captured through collaborative efforts in the International Pediatric Stroke Study (IPSS). This study explores the use of an advanced artificial intelligence program, the Generative Pre-trained Transformer (GPT), to enter pediatric stroke data into the IPSS. MethodsThe most recent 50 clinical notes of patients with ischemic stroke or cerebral venous sinus thrombosis at the UTHealth Pediatric Stroke Clinic were deidentified. Domain-specific prompts were engineered for an offline artificial intelligence program (GPT) to answer IPSS questions. Responses from GPT were compared with the human rater. Percent agreement was assessed across 50 patients for each of the 114 queries developed from the IPSS database outcome questionnaire. ResultsGPT demonstrated strong performance on several questions but showed variability overall. In its early iterations it was able to match human judgment occasionally with an accuracy score of 1.00 (n = 20, 17.5%), but it scored as low as 0.26 in some patients. Prompts were adjusted in four subsequent iterations to increase accuracy. In its fourth iteration, agreement was 93.6%, with a maximum agreement of 100% and minimum of 62%. Of 2400 individual items assessed, our model entered 2247 (93.6%) correctly and 153 (6.4%) incorrectly. ConclusionsAlthough our tailored generative model with domain-specific prompt engineering and ontological guidance shows promise for research applications, further refinement is needed to enhance its accuracy. It cannot enter data entirely independently, but it can be employed in tandem with human oversight contributing to a collaborative approach that reduces overall effort.

Association between COVID-19 Vaccination (ChAdOx1-S) and Thromboembolic, Thrombocytopenic, Hemorrhagic Events: A Systematic Review and Meta-analysis of Analytical Epidemiological Studies.

We conducted a systematic review of analytical epidemiological studies to assess the association between ChAdOx1-S vaccination and thromboembolic, thrombocytopenic, and hemorrhagic events. We searched Medline, Embase, Google Scholar, WHO-COVID-19 database, and medRxiv for studies evaluating the association between ChAdOx1-S and vascular events. Primary outcomes of interest were cerebral venous sinus thrombosis, peripheral venous thrombosis (PVT), and thrombocytopenia. Two independent reviewers screened for eligible studies, extracted data, and assessed the risk of bias. The DerSimonian-Laird random effects model was used to pool the incidence rate ratios (IRRs) separately for the first and second doses. Heterogeneity was assessed using I2 statistics. Twenty studies were included, of which 11 were self-controlled case series, and nine were cohort studies (254 million participants). Pooling of 17 studies showed a higher risk of cerebrovascular thrombosis (IRR = 3.5, 95% CI = 2.2-5.4, I2 = 79%), PVT (IRR = 2.0, 95% CI = 1.1-3.5, I2 = 95%) and thrombocytopenia (IRR = 1.6, 95% CI = 1.4-1.9, I2 = 93%) among those who received ChAdOx1-S vaccination as compared to controls. No increased risk was seen after the second dose or for secondary outcomes. There is moderate-to-high certainty of the evidence for the increased risk of cerebral venous sinus thrombosis, PVT, and thrombocytopenia following the first dose of the ChAdOx1-S vaccine. Systematic Review Registration: PROSPERO CRD42022372768.

Perfusion MRI in Cerebral Venous and Sinus Thrombosis.

Cerebral venous and sinus thrombosis (CVST) leads to perfusion abnormality in the brain. Our aim was to assess perfusion abnormalities in the center and periphery of the parenchymal lesion in CVST patients and correlate with the clinical outcome. Dynamic susceptibility contrast (DSC) perfusion imaging was performed in patients with CVST. Relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT) values were obtained in the center and periphery of the parenchymal lesion. A total of 30 consecutive patients of CVST were included in the study. Parenchymal lesion was present in 21 (70%) patients. In rest 9, perfusion map was showing some abnormality although conventional MRI was normal. Mean rCBV and MTT were increasing from periphery of the lesion to the center (rCBV 69.93 ± 29.79 at periphery (PL2) to 92.49 ± 32.07 at center of the lesion and 69.19 ± 25.52 at normal appearing contralateral brain parenchyma (NABP). MTT 11.83 ± 3.76 at periphery (PL2) to 15.27 ± 5.49 at center of the lesion and 10.63 ± 3.37 at NABP). rCBV and MTT from abnormal perfusion areas from 9 patients without parenchymal abnormalities are 92.89 ± 17.76 and 15.92 ± 3.66 respectively. There is an increasing trend of MTT and rCBV from periphery to center of the parenchymal lesion. MTT is the most consistent parameter to be abnormal in patients of CVST even in patients without parenchymal lesion. Residual neurological deficit was found in patients with increased rCBV and having large hemorrhagic infarct.