Diagnostic accuracy of noncontrast CT imaging markers in cerebral venous thrombosis

Derivation of a clinical decision rule to exclude cerebral venous sinus thrombosis in emergency department patients: A retrospective cohort study

OBJECTIVE

To derive a clinical decision rule to exclude cerebral venous sinus thrombosis (CVST) in the ED. A secondary aim was to derive a rule that incorporated clinical parameters and the non-contrast CT brain.

METHODS

Single-centre, retrospective cohort study. Patients suspected of CVST were identified from the radiology database for CT/MR venograms. Clinical features included in the rule were determined by literature review. The presence of these features in participants was determined by chart review. Variables were tested for univariate association with CVST using logistic regression. Variable selection was accomplished using a forward-stepwise process, calculating the sensitivity/specificity of a rule containing the variable of most significance, then repeating the process after adding the next most significant variable.

RESULTS

Forty-five out of 912 participants had confirmed CVST. The primary clinical rule was answering 'no' to all the following: any prothrombotic risk factor, age ≥54 years, confusion: sensitivity 95.6% (95% confidence interval [CI] 84.9-99.5%), specificity 40.9% (95% CI 37.6-44.2%), negative predictive value 99.4% (95% CI 97.9-99.9%) and positive predictive value 7.7% (95% CI 7.1-8.3%). The rule classified 39.5% of participants as CVST ruled out. The rule incorporating the non-contrast CT brain was answering 'no' to all the following: abnormal non-contrast CT brain, any prothrombotic risk-factor, age ≥54 years, confusion: sensitivity 100.0% (95% CI 91.6-100.0%), specificity 42.0% (95% CI 38.7-45.4%), negative predictive value 100.0% (95% CI not calculated) and positive predictive value 7.8% (95% CI 7.4-8.2%). The rule classified 40.0% of participants as CVST ruled out.

CONCLUSIONS

A clinical decision rule was derived to rule out CVST. These results require validation before adoption into clinical practice.

A dynamic nomogram for predicting intraoperative brain bulge during decompressive craniectomy in patients with traumatic brain injury: a retrospective study

OBJECTIVE

The aim of this paper is to investigate the risk factors associated with intraoperative brain bulge (IOBB), especially the computed tomography (CT) value of the diseased lateral transverse sinus, and to develop a reliable predictive model to alert neurosurgeons to the possibility of IOBB.

METHODS

A retrospective analysis was performed on 937 patients undergoing traumatic decompressive craniectomy. A total of 644 patients from Fuzong Clinical Medical College of Fujian Medical University were included in the development cohort, and 293 patients from the First Affiliated Hospital of Shantou University Medical College were included in the external validation cohort. Univariate and multifactorial logistic regression analyses identified independent risk factors associated with IOBB. The logistic regression models consisted of independent risk factors, and receiver operating characteristic curves, calibration, and decision curve analyses were used to assess the performance of the models. Various machine learning models were used to compare with the logistic regression model and analyze the importance of the factors, which were eventually jointly developed into a dynamic nomogram for predicting IOBB and published online in the form of a simple calculator.

RESULTS

IOBB occurred in 93/644 (14.4%) patients in the developmental cohort and 47/293 (16.0%) in the validation cohort. Univariate and multifactorial regression analyses showed that age, subdural hematoma, contralateral fracture, brain contusion, and CT value of the diseased lateral transverse sinus were associated with IOBB. A logistic regression model (full model) consisting of the above risk factors had excellent predictive power in both the development cohort [area under the curve (AUC)=0.930] and the validation cohort (AUC=0.913). Among the four machine learning models, the AdaBoost model showed the best predictive value (AUC=0.998). Factors in the AdaBoost model were ranked by importance and combined with the full model to create a dynamic nomogram for clinical application, which was published online as a practical and easy-to-use calculator.

CONCLUSIONS

The CT value of the diseased lateral transverse is an independent risk factor and a reliable predictor of IOBB. The online dynamic nomogram formed by combining logistic regression analysis models and machine learning models can more accurately predict the possibility of IOBBs in patients undergoing traumatic decompressive craniectomy.

Prediction Score for Clinical Outcome of Chinese Patients with Cerebral Venous Thrombosis

Background

Although numerous prognostic markers for cerebral venous thrombosis (CVT) have been reported, inconsistencies exist in their predictive values, leading to contradictory forecasts. This study was designed to develop a comprehensive clinical outcome prediction score for Chinese patients with CVT, integrating key prognostic markers to furnish an overall prognosis.

Methods

Participants were selected from the CCC cohort, a multicenter study encompassing 26 tertiary hospitals across mainland China. Between January 2021 and May 2022, 170 patients with CVT were prospectively recruited. Potential prognostic markers were extracted from the CCC database and subsequently analyzed.

Results

Age, diastolic blood pressure (DBP), neutrophil-to-lymphocyte ratio (NLR), and neuron-specific enolase (NSE) emerged as significant prognostic markers for CVT after a multivariate logistic analysis. Specific cut-off values were identified: Age > 27.5 years, DBP > 79.5 mmHg, NLR > 6.6, and NSE >16.5 ng/mL. The points assigned were: one each for age and NSE level, two for DBP, and three for NLR, based on the adjusted odds ratio. A positive correlation was found between the baseline CVT outcome score and the mRS at six months' follow-up. A CVT outcome score of 3.5 served as an effective cut-off value for predicting CVT clinical outcomes. Further analysis revealed that patients with CVT outcome scores > 3 exhibited significantly higher mRS scores than those with scores ≤ 3.

Conclusion

This study led to the development of the CVT outcome score, consisting of age, DBP, NLR, and NSE level, specifically for Chinese patients with CVT. The baseline CVT outcome score positively correlated with the mRS score at the six-month follow-up. A CVT outcome score of > 3 serves as a reliable indicator to identify patients at a higher risk of unfavorable clinical outcomes. These patients may benefit from additional care and early interventions to avert potential deterioration.

Diagnosis and Treatment of Cerebral Venous Thrombosis

OBJECTIVE

Cerebral venous thrombosis (CVT), thrombosis of the dural sinus, cerebral veins, or both, is a rare cerebrovascular disease. Although mortality rates after CVT have declined over time, this condition can result in devastating neurologic outcomes. This article reviews the latest literature regarding CVT epidemiology, details new factors associated with the development of CVT, and describes advances in CVT treatment. It also contains a discussion of future directions in the field, including novel diagnostic imaging modalities, and potential strategies to reduce the risks associated with CVT.

LATEST DEVELOPMENTS

The incidence of CVT may be as high as 2 per 100,000 adults per year. It remains a difficult condition to diagnose given its variable clinical manifestations and the necessity of neuroimaging for confirmation. The COVID-19 pandemic has revealed a novel CVT trigger, vaccine-induced immune thrombotic thrombocytopenia (VITT), as well as an association between COVID-19 infection and CVT. Although VITT is a very rare event, timely diagnosis and treatment of CVT due to VITT likely improves patient outcomes. Direct oral anticoagulants are currently being used to treat CVT and emerging data suggest that these agents are as safe and effective as vitamin K antagonists. The role of endovascular therapy to treat CVT, despite a recent clinical trial, remains unproven.

ESSENTIAL POINTS

The incidence of CVT has increased, outcomes have improved, and the use of direct oral anticoagulants to treat CVT represents an important advance in the clinical care of these patients. Rates of CVT as a complication of COVID-19 vaccines using adenoviral vectors are very low (<5 per million vaccine doses administered), with the benefits of COVID-19 vaccination far outweighing the risks.

Diagnostic Sensitivity of Unenhanced CT for Cerebral Venous Thrombosis: Can Clot Density Measurement Replace CT Venogram?

Objectives Cerebral venous sinus thrombosis is an important cause of stroke in young adults. Noncontrast-enhanced CT head (NECT) is almost always the first investigation.

Our objectives were as follows:

1. How accurately does venous sinus density on NECT predict the presence of clot on CT venogram (CTV)?

2. Whether repeated measurements changed the confidence?

3. How many venous sinus thrombus would be missed if we do not do a CTV?

4. Can clot density measurement replace CTV?

Methods Multicenter case–control study was designed with data from seven hospitals. Inclusion criteria: all CT and magnetic resonance imaging venograms with a prior NECT, performed between 1.1.2018 and 31.12.2018 (12 months), were included. Hounsfield unit (HU) values were calculated at the site of highest density on the NECT. Logistic regression analysis was performed using STATA.

Result Two-hundred seventy-seven cases met the criteria with 33 positive cerebral venous thrombosis (density on NECT 60–92 HU) and 244 negative examinations (density on NECT 31–68 HU). Area under the curve for average clot density on NECT was 0.9984.

Conclusion We found a strong relationship between sinus density on NECT and outcome of CTV. Repeating density measurements did not add any predictive value or changed outcome.

Advances in Knowledge Density 70 HU or higher on NECT always resulted in a positive CTV but would miss a fifth of the positives. Cutoff at 60 HU would not miss any but result in significant false positives. An efficient option could be to limit CTV to sinus densities 60 to 70 HU only. However, a larger study would be required for such change in practice.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

Diagnostic performance of MR black-blood thrombus imaging for cerebral venous thrombosis in real-world clinical practice

OBJECTIVES

MR black-blood thrombus imaging (BTI) has been developed for the detection of cerebral venous thrombosis (CVT). Yet, there is a lack of real-world data to verifying its clinical performance. This study aims to evaluate the performance of BTI in diagnosing and staging CVT in a 5-year period.

METHODS

Patients suspected of CVT were enrolled between 2014 and 2019. Patients with or without BTI scans were classified into group A and group B, respectively. The prevalence of correct diagnosis of CVT and patients with evaluable clot age were compared. The diagnostic performance of BTI including sensitivity, specificity, and specific staging information was further analyzed.

RESULTS

Two hundred and twenty-one of the 308 patients suspected of CVT were eligible in the current study (114 in group A and 97 in group B), with 125 diagnosed by multidisciplinary teams to have CVTs (56 in group A, 69 in group B). The rate of correct diagnosis of CVT was higher in group A than that in group B (94.7% vs 60.8%, p < 0.001, x² = 36.517) after adding BTI images. The percent of patients with evaluable staged segments between the two groups were 96.4% and 33.9%, respectively (x² = 48.191, p < 0.001). BTI showed a sensitivity of 96.4% and 87.9% in the detection of CVT on per-patient and per-segment level, respectively. Up to 98.1% of all thrombosed segments could be staged by BTI and 59.6% of them were matched with clinical staging.

CONCLUSIONS

In the actual clinical practice, BTI improves diagnostic confidence and has an excellent performance in confirming and staging CVT.

KEY POINTS

• Black-blood thrombus imaging has good diagnostic performance in detecting cerebral venous thrombosis compared to traditional imaging methods with strong evidence in the actual clinical setting. • BTI helps clinicians to diagnose CVT with more accuracy and confidence, which can be served as a promising imaging examination. • BTI can also provide additional information of different thrombus ages objectively, the valuable reference for clinical strategy.

Stroke Associated with COVID-19 Vaccines

Objectives

Development of safe and effective vaccines against coronavirus disease 2019 (COVID-19) remains the cornerstone of controlling this pandemic. However, there are increasing reports of various types of stroke including ischemic stroke, and hemorrhagic stroke, as well as cerebral venous sinus thrombosis (CVST) after COVID-19 vaccination. This paper aims to review reports of stroke associated with COVID-19 vaccines and provide a coherent clinical picture of this condition.

Materials and methods

A literature review was performed with a focus on data from recent studies.

Results

Most of such patients are women under 60 years of age and who had received ChAdOx1 nCoV-19 vaccine. Most studies reported CVST with or without secondary ischemic or hemorrhagic stroke, and some with Vaccine-induced Thrombotic Thrombocytopenia (VITT). The most common clinical symptom of CVST seen after COVID-19 vaccination was headache. The clinical course of CVST after COVID-19 vaccination may be more severe than CVST not associated with COVID vaccination. Management of CVST following COVID-19 vaccination is challenging and may differ from the standard treatment of CVST. Low molecular weight heparin is commonly used in the treatment of CVST; however, it may worsen outcomes in CVST associated with VITT. Furthermore, administration of intravenous immunoglobulin and high-dose glucocorticoids have been recommended with various success rates.

Conclusion

These contradictory observations are a source of confusion in clinical decision-making and warrant further study and development of clinical guidelines. Clinicians should be aware of clinical presentation, diagnosis, and management of stroke associated with COVID-19 vaccination.

Acute T2*-Weighted Magnetic Resonance Imaging Detectable Cerebral Thrombosis in a Rat Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is associated with a high incidence of morbidity and mortality, particularly within the first 72 h after aneurysm rupture. We recently found ultra-early cerebral thrombosis, detectable on T2* magnetic resonance imaging (MRI), in a mouse SAH model at 4 h after onset. The current study examined whether such changes also occur in rat at 24 h after SAH, the vessels involved, whether the degree of thrombosis varied with SAH severity and brain injury, and if it differed between male and female rats. Adult Sprague Dawley rats were subjected to an endovascular perforation SAH model or sham surgery and underwent T2 and T2* MRI 24 h later. Following SAH, increased numbers of T2* hypointense vessels were detected on MRI. The number of such vessels correlated with SAH severity, as assessed by MRI-based grading of bleeding. Histologically, thrombotic vessels were found on hematoxylin and eosin staining, had a single layer of smooth muscle cells on alpha-smooth muscle actin immunostaining, and had laminin 2α/fibrinogen double labeling, suggesting venule thrombosis underlies the T2*-positive vessels on MRI. Capillary thrombosis was also detected which may follow the venous thrombosis. In both male and female rats, the number of T2*-positive thrombotic vessels correlated with T2 lesion volume and neurological function, and the number of such vessels was significantly greater in female rats. In summary, this study identified cerebral venous thrombosis 24 h following SAH in rats that could be detected with T2* MRI imaging and may contribute to SAH-induced brain injury.

Cerebral Venous Thrombosis: A Challenging Diagnosis; A New Nonenhanced Computed Tomography Standardized Semi-Quantitative Method

Cerebral venous sinus thrombosis (CVST) on non-contrast CT (NCCT) is often challenging to detect. We retrospectively selected 41 children and 36 adults with confirmed CVST and two age-matched control groups with comparable initial symptoms. We evaluated NCCT placing four small circular ROIs in standardized regions of the cerebral dural venous system. The mean and maximum HU values were considered from each ROI, and the relative percentage variations were calculated (mean % variation and maximum % variation). We compared the highest measured value to the remaining three HU values through an ad-hoc formula based on the assumption that the thrombosed sinus has higher attenuation compared with the healthy sinuses. Percentage variations were employed to reflect how the attenuation of the thrombosed sinus deviates from the unaffected counterparts. The attenuation of the affected sinus was increased in patients with CVST, and consequently both the mean % and maximum % variations were increased. A mean % variation value of 12.97 and a maximum % variation value of 10.14 were found to be useful to distinguish patients with CVST from healthy subjects, with high sensitivity and specificity. Increased densitometric values were present in the site of venous thrombosis. A systematic, blind evaluation of the brain venous system can assist radiologists in identifying patients who need or do not need further imaging.

Diagnostic and treatment recommendations from the FACME ad-hoc expert working group on the management of cerebral venous sinus thrombosis associated with COVID-19 vaccination

INTRODUCTION

Cases of cerebral venous sinus thrombosis have been reported in individuals vaccinated against COVID-19 with non-replicating adenoviral vector vaccines. We issue our recommendations on the diagnosis and management of patients presenting this complication.

METHODS

The multidisciplinary working group, led by the Spanish Federation of Medical and Scientific Associations (FACME) and including representatives of several scientific societies, reviewed the available evidence from the literature and reports of the European Medicines Agency. We establish a definition for suspected cases and issue diagnostic and treatment recommendations regarding vaccine-induced immune thrombotic thrombocytopaenia.

RESULTS

We define suspected cases as those cases of cerebral venous sinus thrombosis occurring between 3 and 21 days after the administration of non-replicating adenoviral vector vaccines, in patients with a platelet count below 150 000/μL or presenting a decrease of 50% with respect to the previous value. Findings suggestive of vaccine-induced immune thrombotic thrombocytopaenia include the presence of antibodies to platelet factor 4, D-dimer levels 4 times greater than the upper limit of normal, and unexplained thrombosis. The recommended treatment includes intravenous administration of non-specific human immunoglobulin or alternatively plasmapheresis, avoiding the use of heparin, instead employing argatroban, bivalirudin, fondaparinux, rivaroxaban, or apixaban for anticoagulation, and avoiding platelet transfusion.

CONCLUSIONS

Non-replicating adenoviral vector vaccines may be associated with cerebral venous sinus thrombosis with thrombocytopaenia; it is important to treat the dysimmune phenomenon and the cerebral venous sinus thrombosis.

Diagnostic and treatment recommendations from the FACME ad-hoc expert working group on the management of cerebral venous sinus thrombosis associated with COVID-19 vaccination

Introducción

Se han reportado casos de trombosis venosas cerebrales en personas vacunadas frente a COVID-19 con vacunas vectorizadas con adenovirus no replicantes. Aportamos recomendaciones sobre el diagnóstico y manejo de pacientes con esta complicación.

Método

El grupo de trabajo multidisciplinar, liderado por la Federación de Asociaciones Científico Médicas Españolas y representado por distintas sociedades científicas, revisó la evidencia disponible publicada en la literatura y en los informes de la Agencia Europea de Medicamentos. Se estableció una definición de caso sospechoso y recomendaciones diagnóstico-terapéuticas de la trombocitopenia trombótica inducida por la vacunación.

Resultados

Se considera caso sospechoso aquella trombosis venosa cerebral ocurrida entre 3 y 21 días tras la administración de vacunas no replicantes de adenovirus que presenten un valor de plaquetas inferior a 150.000 plaquetas por μL o un descenso del 50% respecto de la cifra previa. Los datos indicativos de trombocitopenia trombótica inducida por la vacunación incluyen la presencia de anticuerpos antifactor plaquetario tipo 4, la elevación de dímero-D 4 veces por encima del límite superior de la normalidad o la ausencia de justificación de la trombosis. En su tratamiento, se recomienda administrar inmunoglobulina humana inespecífica intravenosa o realizar plasmaféresis en su defecto, evitar el uso de heparina, empleando como anticoagulantes argatroban, bivalirudina, fondaparinux, rivaroxabán o apixabán, y evitar la transfusión de plaquetas.

Conclusiones

Las vacunas de vectores no replicantes de adenovirus pueden asociarse a trombosis venosas cerebrales con trombocitopenia, en cuyo manejo es importante el tratamiento del fenómeno disinmune y de la trombosis venosa cerebral.

Cerebral Venous Thrombosis in Sub-Saharan Africa: A Systematic Review

BACKGROUND

The clinical epidemiology of cerebral venous thrombosis (CVT) in Sub-Saharan Africa is unknown. Such information may be relevant for service planning, prevention and for adapting existing CVT management guidelines to that zone of the World.

AIMS

Systematic review to describe the demography, associated conditions, clinical and neuroimaging features, treatment and outcome of CVT in Sub-Saharan Africa.

SUMMARY OF REVIEW

We searched MEDLINE, Cochrane Database of Systematic Reviews, clinicaltrials.gov and reference lists of included studies for studies reporting original data on CVT in sub-Saharan Africa. We included 20 observational studies describing 287 CVT patients, 11 case reports (13 patients) and 9 case series (274 patients). All studies had a high risk of bias. In case series 58.6 % of the patients were female, the most common associated condition was infection (63.1%), followed by oral contraceptives (7.3%), pregnancy/puerperium (6.2 %), and prothrombotic conditions (2.2%). CT was the most common method to diagnose CVT (85%). Ninety-nine percent (101/102) of patients reported in case series after the year 2000 were anticoagulated. In case series, 21/210 with information (10 %) patients died in the acute phase, while 60/129 with information (46.5%) recovered without sequels.

CONCLUSIONS

The low number of reported CVT cases from Sub-Saharan Africa suggests that CVT is either infrequent, not diagnosed or not reported. Infection is the most common risk factor. Most CVT cases were confirmed by CT alone. Almost all patients reported after year 2000 received anticoagulation. Death rate was higher than in high income countries.

Evaluating thunderclap headache

PURPOSE OF REVIEW

Thunderclap headache (TCH) is an abrupt-onset of severe headache that needs to be thoroughly investigated because the most common secondary cause is subarachnoid hemorrhage (SAH). There has been no consensus guideline regarding the diagnostic workup. This review aims to provide an update on the evaluation of TCH.

RECENT FINDINGS

The most important update in the 2019 American College of Emergency Physicians guideline for evaluation of acute headache in the emergency department is that negative noncontrast brain computed tomography (CT) findings within 6 h from ictus essentially excludes SAH. Additionally, the updated guideline recommends that after a negative brain CT, CT angiogram is a reasonable alternative to lumbar puncture if clinical suspicion of an intracranial source of SAH is high. An important update of reversible vasoconstriction syndrome (RCVS), the second most common etiology of TCH, is the RCVS2 score development based on clinical and radiological features, providing high specificity and sensitivity for distinguishing RCVS from other intracranial arteriopathies.

SUMMARY

Although the evaluation of TCH is exhaustive, the potentially catastrophic consequence of a missed diagnosis of sentinel headache justifies the efforts. Awareness of the clinical features and application of diagnostic tools specific for different pathological conditions can facilitate the diagnostic workup.

Current imaging modalities for diagnosing cerebral vein thrombosis - A critical review

Cerebral vein thrombosis (CVT) is a rare presentation of venous thromboembolism. Prompt and accurate diagnosis is essential as delayed recognition and treatment may lead to permanent disability or even death. Since no validated diagnostic algorithms exist, the diagnosis of CVT mainly relies on neuroimaging. Digital subtraction angiography (DSA) is the historical diagnostic standard for CVT, but is rarely used nowadays and replaced by computed tomography (CT) and magnetic resonance imaging (MRI). High quality studies to evaluate the diagnostic test characteristics of state of the art imaging modalities are however unavailable to date. This review provides an overview of the best available evidence regarding the diagnostic performance of CT and MRI for the diagnosis of CVT. Notably, available studies are observational, mostly small, outdated, and with a high risk of bias. Therefore, direct comparison between studies is difficult due to large diversity in study design, imaging method, reference standard, patient selection and sample size. In general, contrast-enhanced techniques are more accurate for the diagnosis of CVT then non-contrast-enhanced techniques. CT venography and MRI have been both reported to be adequate for establishing a final diagnosis of CVT, but choice of modality as used in clinical practice depends on availability, local preference and experience, as well as patient characteristics. Our review underlines the need for high-quality diagnostic studies comparing CT venography and MRI in specific settings, to improve clinical care and standardize clinical trials.