Cortical vein thrombosis: the diagnostic value of different imaging modalities

Clinical and neuroimaging precursors in cerebral amyloid angiopathy: impact of the Boston criteria version 2.0

BACKGROUND AND PURPOSE

Although the Boston criteria version 2.0 facilitates the sensitivity of cerebral amyloid angiopathy (CAA) diagnosis, there are only limited data about precursor symptoms. This study aimed to determine the impact of neurological and imaging features in relation to the time of CAA diagnosis.

METHODS

Patients diagnosed with probable CAA according to the Boston criteria version 1.5, treated between 2010 and 2020 in our neurocentre, were identified through a keyword search in our medical database. Neuroimaging was assessed using Boston criteria versions 1.5 and 2.0. Medical records with primary focus on the clinical course and the occurrence of transient focal neurological episodes were prospectively evaluated.

RESULTS

Thirty-eight out of 81 patients (46.9%) exhibited transient focal neurological episodes, most often sensory (13.2%) or aphasic disorders (13.2%), or permanent deficits at a mean time interval of 31.1 months (SD ±26.3; range 1-108 months) before diagnosis of probable CAA (Boston criteria version 1.5). If using Boston criteria version 2.0, all patients receiving magnetic resonance imaging (MRI) met the criteria for probable CAA, and diagnosis could have been made on average 44 months earlier. Four patients were younger than 50 years, three of them with supporting pathology. Cognitive deficits were most common (34.6%) at the time of diagnosis.

CONCLUSIONS

Non-haemorrhagic MRI markers enhance the sensitivity of diagnosing probable CAA; however, further prospective studies are proposed to establish a minimum age for inclusion. As the neurological overture of CAA may occur several years before clinical diagnosis, early clarification by MRI including haemosensitive sequences are suggested.

Utility of 3D T1-weighted turbo spin echo black blood sequence for the diagnosis of cerebral venous thrombosis

PURPOSE

Accurate assessment of dural sinus, deep and cortical venous thrombosis on MR imaging is challenging. The aim of this study is to evaluate the accuracy of 3D-T1 turbo spin echo (T1S), sequences in detecting venous thrombosis and comparing it with susceptibility-weighted imaging (SWI), magnetic resonance venography (MRV) and post contrast T1 magnetization-prepared rapid acquisition gradient echo (T1C).

METHODS

A blinded retrospective observational analysis of 71 consecutive patients evaluated for cerebral venous thrombosis (CVT) and 30 control patients was performed. Multimodality reference standard adopted included T1C, SWI with MRV. Sub-analyses in superficial, deep and cortical venous segments were performed in addition to correlation of signal intensity of thrombus with the clinical stage.

RESULTS

A total of 2222 segments in 101 complete MRI examinations were evaluated. Sensitivity/specificity/positive predictive value/negative predictive value/accuracy and precision of T1S for detection of cortical vein thrombosis was 0.994/1/1/0.967/0.995/1, 1/0.874/0.949/1/0.963/0.950 for detection of superficial venous sinus thrombosis and 1/1/1/1/1/1 for deep venous thrombosis. The AUC yield for T1S was 0.997 for cortical, 1 for deep and 0.988 for superficial venous segments.

CONCLUSION

T1S paralleled the accuracy of conventional sequences in the overall detection of CVT but showed superior accuracy in the detection of cortical venous thrombosis. It makes a fitting addition to the CVT MRI protocol in scenarios demanding negation of gadolinium administration.

Imaging Approach to Venous Sinus Thrombosis

Cerebral venous thrombosis (CVT) is a rare cerebrovascular disease caused by an occlusion of the cerebral venous sinuses or cortical veins. It has a favorable prognosis if diagnosed and treated early. CVT can be difficult to diagnose on clinical grounds, and imaging plays a key role. We discuss clinical features and provide an overview of current neuroimaging methods and findings in CTV.

Comparison of susceptibility-weighted angiography (SWAN) and T2 gradient-echo sequences for the detection of acute cerebral venous thrombosis

OBJECTIVES

To assess the diagnostic accuracy and lesion conspicuity of susceptibility-weighted angiography (SWAN) and T2* for the clot detection in acute cerebral venous thrombosis (CVT) by comparison with contrast-enhanced MR venography.

METHODS

Venous thrombi detection and conspicuity were assessed by two readers for 18 venous segments on both T2*, SWAN source images, 2D SWAN reformats matching with T2*, and 3D SWAN images (SWAN-MinIP). Images obtained with the three reading techniques were systematically scored and compared to CE MRV findings, in a blinded fashion, per patient and per segment, and compared to each other.

RESULTS

In 30 patients, 137 thrombosed venous segments were evaluated. The sensitivity of T2*, SWAN source images, 2D SWAN, and SWAN MinIP were, respectively, of 89.3%/82.1%, 82.1%, and 82.1% for dural sinus thrombosis and of 100%/100%/100%/96.6% for cortical venous thrombosis. There were significant differences in thrombus detection between T2* and SWAN: T2* versus SWAN source images and 2D SWAN (p = 0.04) and versus SWAN MinIP (p = 0.03). There were no significant differences between the three modalities of SWAN images. T2* was more sensitive than all SWAN images for both sigmoid sinus thrombosis and intracranial internal jugular vein thrombosis (p = 0.04). Inter-observer agreement was slightly superior with T2* (p < 0.05).

CONCLUSION

In this small cohort, SWAN sequence at 3T did not yield additional value for thrombus detection in acute CVT compared to T2*. This study highlights SWAN's greatest weakness both for diagnostic accuracy and lesion conspicuity compared to T2* for acute venous clot detection near the skull base.

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.

Detection of cerebral cortical vein thrombosis with high-resolution susceptibility weighted imaging - A comparison with MR venography and standard MR sequences

PURPOSE

Comparison of the performance of high-resolution susceptibility weighted imaging with standard MR sequences and MR venography to identify cortical vein clots.

METHODS

A retrospective review of 51 consecutive cases of cerebral venous thrombosis and 27 controls was performed with independent analysis of all MR sequences. Reference standard was obtained with consensus in a separate session by reviewing all MR sequences together.

RESULTS

Cortical vein clots were observed in 30 cases including 9 males and 21 females in the age range of 1 month to 70 years (Mean 34.9 ± 20.2 years). Sensitivity, specificity, negative predictive value, positive predictive value and accuracy of susceptibility weighted imaging for the identification of cortical vein clots were 0.93, 1.0, 1.0, 0.96 and 0.97 respectively. For all other sequences, sensitivity ranged from 0.06 to 0.39 and accuracy from 0.60 to 0.73. Combination of all sequences yielded a value of 1.0 for sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the detection of cortical vein clots. Significant result for area under the receiver operating curve was observed only for SWI with a value of 0.91 (p - .000).

CONCLUSION

Susceptibility weighted imaging demonstrates the best sensitivity and accuracy among standard MR sequences including MR venography for the detection of early stage cortical vein clots. However, it needs to be interpreted in combination with other MR sequences for the most accurate evaluation of cortical vein clots.

Cerebral Superficial Siderosis

Superficial siderosis (SS) of the central nervous system constitutes linear hemosiderin deposits in the leptomeninges and the superficial layers of the cerebrum and the spinal cord. Infratentorial (i) SS is likely due to recurrent or continuous slight bleeding into the subarachnoid space. It is assumed that spinal dural pathologies often resulting in cerebrospinal fluid (CSF) leakage is the most important etiological group which causes iSS and detailed neuroradiological assessment of the spinal compartment is necessary. Further etiologies are neurosurgical interventions, trauma and arteriovenous malformations. Typical neurological manifestations of this classical type of iSS are slowly progressive sensorineural hearing impairment and cerebellar symptoms, such as ataxia, kinetic tremor, nystagmus and dysarthria. Beside iSS, a different type of SS restricted to the supratentorial compartment can be differentiated, i.e. cortical (c) SS, especially in older people often due to cerebral amyloid angiopathy (CAA). Clinical presentation of cSS includes transient focal neurological episodes or “amyloid spells”. In addition, spontaneous and amyloid beta immunotherapy-associated CAA-related inflammation may cause cSS, which is included in the hemorrhagic subgroup of amyloid-related imaging abnormalities (ARIA). Because a definitive diagnosis requires a brain biopsy, knowledge of neuroimaging features and clinical findings in CAA-related inflammation is essential. This review provides neuroradiological hallmarks of the two groups of SS and give an overview of neurological symptoms and differential diagnostic considerations.

Thrombosis and thromboembolism: Brighton collaboration case definition and guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of thrombosis and thromboembolism to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected expert reviewers prior to submission.

High-resolution susceptibility-weighted imaging of clots in cerebral venous thrombosis

PURPOSE

To distinguish cerebral venous clots from patent dural sinuses, cortical veins, and calvarium on high-resolution susceptibility-weighted imaging, since there is lack of a well-designed study in the literature.

METHODS

A retrospective review of 51 consecutive cases and 27 controls was performed with susceptibility-weighted imaging independently by two investigators. MR venography along with MR sequences other than the susceptibility-weighted imaging served as the reference standard.

RESULTS

There were 29 males and 49 females in the age range of 1 month to 70 years (mean 27 ± 19.8 years). Substantial (k 0.84 to 1.0) to good (k 0.60 to 0.75) inter-rater agreement was observed on the magnitude images for the demonstration of clots in all venous segments, excluding left sigmoid sinus, jugular bulb, and internal jugular vein (k 0.43 to 0.56). Comparatively magnitude images demonstrated better sensitivity (0.83 (0.54-1.13) to 1.0), specificity (0.92 (0.85-0.99) to 1.0), and negative predictive value (0.98 (0.94-1.02) to 1.0) for the detection of clots across all venous segments. Magnitude images showed positive predictive value ranging from 0.83 (0.66-1.0) to 1.0 for clots anywhere from the anterior aspect of superior sagittal sinus to bilateral transverse sinuses. For the detection of clots from bilateral sigmoid sinuses to internal jugular veins, magnitude images showed relatively better positive predictive value ranging from 0.57 (0.20-0.94) to 0.75 (0.45-1.06) in comparison to the processed magnitude and minimum intensity pixel images.

CONCLUSION

Susceptibility-weighted imaging can successfully distinguish majority of clots from patent dural sinuses, cortical veins, and calvarium with excellent inter-rater agreements.

[Cerebral venous sinus thrombosis after COVID-19 vaccination : Neurological and radiological management]

BACKGROUND

Vaccine-induced cerebral venous and sinus thrombosis (VI-CVST) is a rare complication in recipients of the adenovirus-vectored coronavirus disease 2019 (COVID-19) vaccine ChAdOx1 nCov-19 (Vaxzevria®; AstraZeneca).

OBJECTIVES

Development of a diagnostic and therapeutic standard.

MATERIALS AND METHODS

Analysis of clinical and basic research findings, expert opinions, and experience with our own cases.

RESULTS

VI-CVST usually manifests on day 4-24 after vaccination, mostly in individuals aged < 60 years, and women. In the majority there is an immune pathogenesis caused by antibodies against platelet factor 4/polyanion complexes, leading to thrombotic thrombocytopenia which can result in severe, sometimes fatal, course. The cardinal symptom is headache worsening within days which, however, also can be of variable intensity. Other possible symptoms are seizures, visual disturbance, focal neurological deficits and signs of increased intracranial pressure. If VI-CVST is suspected, the determination of plasma D‑dimer level, platelet count, and screening for heparin-induced thrombocytopenia (HIT-2) are essential for treatment decision-making. Magnetic resonance imaging (MRI) with venous MR-angiography is the neuroimaging modality of choice to confirm or exclude VI-CVST. On T2* susceptibility-weighted MRI, the clot in the sinuses or veins produces marked susceptibility artifacts ("blooming"), which also enables the detection of isolated cortical venous thromboses. MRI/MR-angiography or computed tomography (CT)/CT-angiography usually allow-in combination with clinical and laboratory findings-reliable diagnosis of VI-CVST.

CONCLUSIONS

The clinical suspicion of VI-CVST calls for urgent laboratory and neuroimaging workup. In the presence of thrombocytopenia and/or pathogenic antibodies, specific medications for anticoagulation and immunomodulation are recommended.

Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Cerebral Venous Thrombosis : A Meta-Analysis

Objective

A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not wellunderstood. This study evaluates the effectiveness of DWI in the diagnosis of CVT.

Methods

Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue.

Results

Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference−0.33×10^-3 mm²/s [95% CI, −0.44 to −0.23]; p<0.00001).

Conclusion

DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

Cerebral Venous Thrombosis: Review of Diagnosis, Follow-Up, Late Complications and Potential Pitfalls

Cerebral venous thrombosis is a less common but relevant cause of stroke in adults. The clinical manifestations are nonspecific leading frequently diagnostic delays, so imaging findings are is of vital importance. Conventional imaging modalities, namely computed tomography and magnetic resonance imaging (MRI), allow identification of the thrombus and parenchymal involvement due to venous congestion to a variable degree, but this entity may appears as a nonexpected finding in a nonvenographic study. computed tomography and MRI venographies allow noninvasive confirmation of the diagnosis and adequate characterization of the extent of the thrombus and acute complications, both of them being robust diagnostic techniques. MR venography also can be done without the use of contrast media, which is especially important in certain clinical situations. Cerebral venous thrombosis needs follow-up, and imaging plays a key role in detection of late complications of the disease, including dural arteriovenous fistulas and intracranial hypertension due to veno-occlusive disease. Knowledge of other diseases and conditions that may mimic a thrombus is needed to avoid wrong diagnosis. In this article, we conduct a pictorial comprehensive review of cerebral venous thrombosis, including also the technical aspects of different imaging modalities, diagnosis and acute complications, follow-up, late complications and potential imaging mimics.

Cerebral Venous Thrombosis: A Comprehensive Review

BACKGROUND

Cerebral sinus venous thrombosis (CSVT) is a relatively rare, potentially fatal neurological condition that can be frequently overlooked due to the vague nature of its clinical and radiological presentation. A literature search on PubMed using the keyword "Cerebral sinus venous thrombosis" was performed. We searched for the epidemiology, risk factors, pathophysiology, clinical features, diagnosis, and treatment of CSVT. All full-text articles in the last 10 years, in adults (>18 years), and the English language were included. We aim to give a comprehensive review of CSVT, with a primary focus on the management of the disease.

SUMMARY

The literature search revealed 404 articles that met our criteria. CSVT is a relatively rare condition that accounts for approximately 1% of all forms of stroke. They can be subdivided into acute, subacute, and chronic forms based on the time of onset of clinical symptoms. It is a multifactorial disease, and the major forms of clinical presentation include isolated intracranial hypertension syndrome, focal neurological deficits, and cavernous sinus syndrome. MRI with magnetic resonance venogram (MRV) is considered the gold standard for diagnosis. Anticoagulation with heparin or low-molecular-weight heparin is the mainstay of treatment. Endovascular management is indicated for those cases with severe symptoms or worsening of symptoms despite anticoagulation therapy. Favorable outcomes have been reported in patients who receive early diagnosis and treatment.

CONCLUSION

CSVT is a potentially fatal neurological condition that is often under-diagnosed due to its nonspecific presentation. Timely diagnosis and treatment can reduce morbidity and mortality, remarkably improving the outcome in affected individuals.

Labbé vein thrombosis

PURPOSE

Evaluate the prevalence of Labbé vein thrombosis (LVT) and its liability for the lesions observed in the case of associated ipsilateral transverse sinus thrombosis (TST).

METHODS

MRI findings of 58 consecutive patients (≥ 18 years) with acute LVT and TST (group 1) were compared with those of 149 patients with acute TST-no LVT (group 2) observed during the same period.

RESULTS

The prevalence of LVT was 15.2%. Group 1: TST extended to sigmoid sinus in 94.8%, resulting in complete sinuses occlusion. Any lesion was observed in 81% within LV territory: swelling (n = 5, 8.6%), edema (n = 9; 15.5%), non-hemorrhagic Infarct (n = 1; 1.7%), multiple temporal lobe hemorrhages (n = 31; 53.5%), temporal lobe hematoma (n = 13; 22.4%), and pericerebral hemorrhages (n = 28; 50%). The hemorrhagic lesions were not related to dominant TST or to extensive venous thrombosis. There was a prevalence of left TST- LVT (n = 32; 55.2%) and a higher prevalence of hemorrhagic lesions in this subset (59.4%). Risk factors were also associated (p = 0.03). Group 2: the TST resulted in an occlusion of the TS: (i) complete (n = 16; 10.7%); (ii) incomplete (n = 97; 82.8%); and (iii) segmental, involving the TS before (n = 32; 21.5%) or after (n = 10; 6.7%) LV ending within the TS. No parenchymal/pericerebral lesions were associated.

CONCLUSION

This study shows a strong association between the following: (i) the extent of thrombosis in the TS and the presence of LVT (p < 0.0001), (ii) the concomitance of LVT-TST and the presence of lesions in the LV territory and at the temporo-frontal convexity, (iii) risk factors and group 1 (p = 0.03).

The clinical characteristic, diagnosis, treatment, and prognosis of cerebral cortical vein thrombosis: a systematic review of 325 cases

Cerebral cortical vein thrombosis (CCVT) is a rare type of cerebral venous thrombosis, which is frequently combined with cerebral venous sinus thrombosis (CVST). We aimed to compare the difference of clinical features between the isolated and the combined subtypes of CCVT. A literature search was conducted utilizing the PubMed Central and EMBASE databases to identify studies up to Dec 2019. Clinical manifestations, presumable risk factors, imaging modalities, radiological findings, treatment, and prognosis in patients with CCVT were recorded. 335 publications were identified (n = 325, 141 males and 184 females, mean age 40.24 ± 16.26 years). Headaches (46.8%), motor/sensory disorders (43.3%), and seizures (42.5%) were commonly seen. Pregnancy/postpartum (n = 29), oral contraception use (n = 15), fertility drug use (n = 4) ranked the top three comorbidities of CCVT in female patients, while for general populations, thrombophilia, invasive interventions in the cerebrospinal system, as well as malignancy, would be the common risk factors. MRV and DSA were more likely to confirm diagnosis. More than 30% of CCVT presented brain lesions, including infarction (6.5%) and hemorrhage (24.0%). Isolated CCVT was prone to develop hemorrhagic infarction while combined CCVT was more likely to have ischemic lesions. More than 90% of the patients acquired good outcomes at discharge or short-term follow-up (within one year). There is a difference between Isolated CCVT and CCVT combined CVST on the sites and types of brain lesions. MRV and DSA may contribute to the final diagnosis. Most patients acquired complete or partial recovery of clinical symptoms or imaging presentations after long-term anticoagulation (3-6 months).

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.

Imaging findings of the orbital and intracranial complications of acute bacterial rhinosinusitis

In patients with acute bacterial rhinosinusitis severe orbital and intracranial complications can occur. This review will illustrate the anatomic relationship between the paranasal sinuses and the orbital and intracranial compartments. Subsequently, the spectrum of orbital and intracranial complications of rhinosinusitis and related imaging findings will be discussed and illustrated by case material from daily practice.

TEACHING POINTS

• Acute bacterial rhinosinusitis can cause severe orbital and intracranial complications. • If orbital or intracranial complications are suspected, cross-sectional imaging is mandatory. • Infection can spread from the ethmoid sinus to the orbit through the lamina papyracea. • Frontal sinusitis can spread intracranially through dehiscences or osteomyelitis. • Radiologists must recognize imaging findings of complications of acute bacterial rhinosinusitis.

Isolated cortical vein thrombosis: case series

OBJECT

Isolated cortical vein thrombosis (ICVT) accounts for less than 1% of all cerebral infarctions. ICVT may cause irreversible parenchymal damage, rendering early and accurate diagnosis critical. This case series and literature review presents the clinical and radiological findings in 7 patients with ICVT, and highlights risk factors and imaging modalities that may be most beneficial in rendering an accurate and timely diagnosis.

METHODS

Patients with CT and MRI findings consistent with ICVT examined between January 2011 and June 2014 were included in this retrospective review.

RESULTS

Seven patients (5 females, 2 males), ranging in age from 11 months to 34 years, met the inclusion criteria. The most common clinical presentations were headaches (n = 4) and seizures (n = 3). The most common comorbidities noted in these patients were hypercoagulable states (n = 4) and intracranial hypotension (n = 3). Five patients had intraparenchymal involvement. CT suggested the correct diagnosis in 4 patients, and MRI confirmed the diagnosis in all 7 patients. All patients who received anticoagulation therapy (n = 5) experienced complete resolution of their symptoms.

CONCLUSIONS

The majority of these patients were adult females, consistent with published data. Seizures and headaches were the most common presenting symptoms. Hypercoagulable state and intracranial hypotension, both known risk factors for thrombosis, were the most commonly noted ICVT risk factors. Intraparenchymal involvement was prevalent in nearly all ICVT cases and presented as vasogenic edema, early intraparenchymal hemorrhage, or hemorrhagic venous infarction. Susceptibility-weighted imaging was the most sensitive imaging technique in diagnosing ICVT.

Cortical superficial siderosis: detection and clinical significance in cerebral amyloid angiopathy and related conditions

Cortical superficial siderosis describes a distinct pattern of blood-breakdown product deposition limited to cortical sulci over the convexities of the cerebral hemispheres, sparing the brainstem, cerebellum and spinal cord. Although cortical superficial siderosis has many possible causes, it is emerging as a key feature of cerebral amyloid angiopathy, a common and important age-related cerebral small vessel disorder leading to intracerebral haemorrhage and dementia. In cerebral amyloid angiopathy cohorts, cortical superficial siderosis is associated with characteristic clinical symptoms, including transient focal neurological episodes; preliminary data also suggest an association with a high risk of future intracerebral haemorrhage, with potential implications for antithrombotic treatment decisions. Thus, cortical superficial siderosis is of relevance to neurologists working in neurovascular, memory and epilepsy clinics, and neurovascular emergency services, emphasizing the need for appropriate blood-sensitive magnetic resonance sequences to be routinely acquired in these clinical settings. In this review we focus on recent developments in neuroimaging and detection, aetiology, prevalence, pathophysiology and clinical significance of cortical superficial siderosis, with a particular emphasis on cerebral amyloid angiopathy. We also highlight important areas for future investigation and propose standards for evaluating cortical superficial siderosis in research studies.

Value of spontaneous hyperdensity of cerebral venous thrombosis on helical CT

BACKGROUND

Excluding a cerebral venous thrombosis (CVT) through imaging is a frequent request in the emergency setting. This assessment often starts by an unenhanced brain computed tomography (CT).

PURPOSE

Re-evaluate the value of spontaneous hyperdensity of CVT on helical unenhanced brain CT.

METHODS

Multicentric retrospective study on CVT probability based on visual assessment of spontaneous hyperdensity of cerebral venous system, performed by four blinded radiologists, individually then collectively, on a population including 14 helical unenhanced brain CTs with CVT and 102 unenhanced brain CTs without CVT (all confirmed by CT or magnetic resonance [MR] venography). Exclusion criteria: no DICOM image, symptoms >15 days, CVT indirect signs on unenhanced CT. A fifth radiologist set 768 regions of interest to measure and to compare the density within the normal venous sinuses and the CVTs.

RESULTS

After consensus reading, sensitivity of this sign for CVT diagnosis was 100%, specificity 95.1%, and negative predictive value (NPV) 100%, with high individual NPV (99-100%). Area under the receiver-operating characteristic curve was 0.992 after consensus (0.976-0.986 individually). The spontaneous density was significantly different (P <0.05) between normal sinuses and CVTs, with a density >70 HU reported only within the CVTs, except for the horizontal part of the superior sagittal sinus (hSSS).

CONCLUSION

The dense triangle sign on helical unenhanced brain CT has an excellent NPV to exclude a sinus thrombosis during the first 2 weeks. However, we believe that visual assessment of spontaneous hyperdensity is not sufficient for the diagnosis of CVT, with possible false-positive of the hSSS on unenhanced CT.

Diffusion-Weighted MR Imaging Findings of Cortical Vein Thrombosis at 3 T

PURPOSE

Diagnosis of cortical vein thrombosis (CVT) on the basis of clot hyperintensity on diffusion-weighted imaging (DWI) has been reported as limited. Our aim was to evaluate different DWI findings of CVT either in isolated form or in combination with sinus thrombosis.

METHODS

In this review-board-approved study, patients with the diagnosis of CVT on magnetic resonance venography (MRV) between 2004 and 2011 were evaluated, and 13 patients with 26 CVT (3 isolated and 23 combined CVT) sites were recruited. The evaluated DWI findings were as follows: (1) the hyperintense clot signal (CS) itself, and (2) clot susceptibility signal (CSS) that appears next to the CVT. Two blinded radiologists evaluated the data. Kappa (κ) statistics was applied for interobserver agreement.

RESULTS

Both readers reported CS within the vascular clot itself in 6 of 26 (23%) CVT sites on DWI. CSS was reported in 16 of 26 (61.5%) CVT sites by reader 1, and in 14 of 26 (54%) of the CVT sites by reader 2. At four CVT sites with thrombosed veins on MRV, both readers reported no DWI findings. When both CS and CSS were evaluated together, reader 1 reported a positive DWI finding in 22 of 26 (84%) of the CVT sites, and reader 2 reported in 20 of 26 (79%) of the sites. κ Statistics showed a very good agreement (κ: 0.87).

CONCLUSIONS

Besides the hyperintense CS, with additional evaluation of the presence of CSS, DWI can provide an additional clue in CVT patients and may suggest its diagnosis, which is important in clinically unsuspected patients.

Isolated superficial sylvian vein thrombosis with long cord sign: case report and review of the literature

Isolated cortical vein thrombosis (ICVT) is extremely rare. Only single case or small series of ICVT have been reported; clinical details are still uncertain. We report a case of isolated superficial sylvian vein thrombosis with exceedingly long cord sign. A 14-year-old female with severe sudden onset headache visited our hospital. Fluid attenuated inversion recovery and echo-planar T2(*) susceptibility-weighted imaging (T2(*)SW) showed a long cord sign on the surface of the sylvian fissure. The patency of dural sinuses and deep cerebral veins were confirmed by magnetic resonance venography (MRV), and diagnosis of ICVT was made. She recovered completely without anticoagulant agents. To clarify the clinical characteristics of ICVT, we reviewed 51 ICVT cases in the literature. In many cases, T2(*)SW was the most useful examination to diagnose ICVT. In contrast with general cerebral venous thrombosis, MRV and conventional angiography were either supporting or useless. Anastomotic cortical veins were involved frequently; symptoms of gyri around the veins were common. It also suggested that ICVTs of the silent area might have been overlooked because of nonspecific symptoms, and more patients with ICVT may exist. In cases involving patients with nonspecific symptoms, the possibility of ICVT should be considered.

[Case of focal convexal subarachnoid hemorrhage presenting as transient ischemic attack mimic]

An 82-year-old man was suspected to have experienced a transient ischemic attack since he developed transient weakness in the right upper limb twice. On admission, neurologic examination yielded normal findings except for mild cognitive impairment. Brain CT and images showed an unexpected finding of acute focal subarachnoid hemorrhage in the left central sulcus, although MR angiography and venography did not show any abnormality. T(2)(*) weighted images showed superficial siderosis in the bilateral frontal lobes, which indicated the possibility of a recurrent subarachnoid hemorrhage. We propose that focal subarachnoid hemorrhage should be included in the differential diagnosis of transient ischemic attack.

Decompressive craniectomy for malignant cerebral oedema of cortical venous thrombosis: an analysis of 13 patients

OBJECTIVE

The study aims to define the role and indication of surgical intervention in cases of malignant cerebral edema in consequence to cortical venous thrombosis (CVT).

METHODS

A retrospective study of 13 patients who underwent decompressive craniectomies for malignant CVT is presented. All patients had supra-tentorial cortical lesions attributable to CVT. The diagnosis was based on CT scan and MRI findings. Patients who presented in a poor clinical status with radiological evidence of malignant cerebral oedema as well as patients who worsened while on medical therapy underwent decompressive hemicraniectomies. Patients were followed up, and the outcome assessed as per Glasgow Outcome Scale (GOS) and Karnofsky Performance Status (KPS) scale.

RESULTS

There were nine females and four males with a mean age of 29.2 years. Eleven patients survived with good outcome (GOs =5, n=5; GOS=4, n=6). At the last follow-up (median 35 months; mean 39 months), the KPS scale was 90 for five, 80 for four and 70 for two survivors. There were two deaths, both in patients with pre-operative Glasgow Coma Scale (GCS) <5.

CONCLUSION

Timely recognition of failure of medical management and an appropriately timed surgical intervention may help to salvage CVT patients who develop malignant cerebral oedema.

Cortical Vein Thrombosis as a Mimic for Isolated Cortical Subarachnoid Hemorrhage and Transient Ischemic Attack

Isolated cortical subarachnoid hemorrhage is rare and poorly understood. Differential diagnoses and proposed pathophysiology vary widely and the diagnostic work-up for these patients who present with transient ischemic attack-like episodes and characteristic imaging findings is still unclear. We report a case of isolated subarachnoid hemorrhage and transient neurologic deficits due to isolated cortical vein thrombosis that was not detected by noninvasive tests. A 75-year-old woman with a history of a lobar intracerebral hemorrhage presented to the Academic Medical Center with sudden-onset transient left upper extremity weakness. Head CT showed a linear hyperdensity in the right precentral gyrus suggestive of isolated subarachnoid hemorrhage. MRI showed susceptibility in the corresponding area. CT angiogram and MRV showed no evidence of a venous thrombosis. The main outcome measures were results of computerized tomography and CT angiogram, magnetic resonance parenchymal and vascular imaging, angiography findings and clinical follow-up at 3 months. Cortical vein thrombosis was detected on conventional angiography. MRI was negative for microhemorrhages. The patient was anticoagulated and had no recurrences of her symptoms. We conclude that cortical vein thrombosis can present as isolated subarachnoid hemorrhage and transient ischemic attack-like episodes and may require angiography for definitive diagnosis.