Dural Venous Sinus Cyst: Clinical and Imaging Findings.

ABSTRACT: Dural venous sinus cysts are very infrequent lesions, generally asymptomatic and incidental. These cystic lesions may include venous structures continuing with superficial cortical veins. A 23-year-old male patient presented with a severe headache. Cranial computed tomography and contrast-enhanced magnetic resonance imaging demonstrated a well-defined, central curvilinear enhanced lesion, located in the superior sagittal sinus which was compatible with the intraluminal dural venous cyst. The patient was included imaging follow-up for possible growth of this cystic lesion. Dural venous sinus cysts are asymptomatic lesions by far. However, these incidental lesions should be followed up just in case the progression-occlusion of the dural sinus. Possible venous components that may have connections with cortical veins should be considered in terms of surgery.

Direct superior sagittal sinus puncture via a surgical burr hole for curative embolization of the complex transverse-sigmoid sinus dural arteriovenous fistula: How I do it.

BACKGROUND: Transvenous embolization of high-grade dural arteriovenous fistulas (dAVFs) is challenging particularly when the direct sinus access is favorable due to the complex venous anatomy which prohibits endovascular access via the transfemoral approach. METHOD: The procedure was conducted in the hybrid operating suite, where a burr hole was performed, followed by direct catheterization of the superior sagittal sinus. Coil embolization was then executed to achieve complete obliteration of the fistula. CONCLUSION: The direct puncture of the superior sagittal sinus is a safe and effective method for treating complex dAVFs. This approach grants access to the fistula channel which facilitates curative embolization.

Computed-tomography evaluation of parietal foramen topography in adults: a retrospective analysis.

BACKGROUND: The parietal foramen (PF) of the skull is a variable anatomic feature with important implications for venous drainage, infection, and injury. Its topography is clinically relevant for neurosurgeons for intracranial navigation and preoperative planning. METHODS: PF topography was investigated in a series of 440 head computed-tomography scans of Omani subjects at Sultan Qaboos University Hospital. The mean age of the patients was 52 ± 17 years and there were 160 males and 280 females. The topography features of the PF, including frequency, diameter, patency, and relative position in relation to the superior sagittal sinus (SSS), were recorded. Additionally, sex and laterality differences in PF parameters were analyzed using a Chi-square test. RESULTS: The overall prevalence of PF was 72.3% (318/440). The bilateral presence of PF was identified in 34% of skulls. Unilateral right-side prevalence was 18.2%, while left prevalence was 13.2% (p = 0.62). The prevalence of unilateral accessory PF on the right side was 1.8%, while it was 1.1% on the left (p = 0.69). PF within the sagittal suture/or intra-sutural PF was observed in 6.8% of skulls, with a frequency of 9.4% in men and 5.4% in women (p = 0.29). The diameter of the PF was 1.45 ± 0.74 mm on the right side, and 1.54 ± 0.99 mm on the left side (p = 0.96). There were 2% of incomplete PF. The PF was located over the SSS in 70.3% on the right side and 53.8% on the left side. No significant differences were observed between the PF topography parameters and sex or laterality. CONCLUSION: The present study for the first time reports the baseline data of PF topography in a large sample of CT scans in the Arab population. The geography and race influence the PF topography differences. PF may be used as a reliable landmark of SSS. The morphological characteristics and distribution of PF reported in this study have clinical implications for imaging diagnosis, intracranial navigation of vascular disorders, and treatment.

Intensive care unit admission is not necessary after venous sinus stenting.

BACKGROUND: Venous sinus stenting (VSS) has emerged as a safe and effective treatment option for idiopathic intracranial hypertension. Many physicians routinely admit patients to the intensive care unit (ICU) for close monitoring, but little data exists on whether this is necessary. METHODS: Electronic medical records of consecutive patients who underwent VSS by the senior author from 2016 to 2022 at a single center were reviewed. RESULTS: 214 patients were included. The mean (SD) age was 35.5 (11.6) and 196 (91.6%) patients were female. A total of 166 (77.6%) patients underwent transverse sinus stenting alone; 9 (4.2%) underwent superior sagittal sinus (SSS) stenting alone, 37 (17.3) concomitant transverse and SSS stenting, and 2 (0.9%) underwent stenting at alternate sites. All patients were planned admission to the regular ward (27.6%) or day hospital (72.4%). Twenty (9.3%) patients were discharged to home the same day as the procedure and 182 (85%) patients were discharged the following day. Major periprocedural complications were identified in 2 (0.93%) patients and minor complications were identified in 16 (7.4%). Only one patient with a subdural hematoma identified in the post-anesthesia care unit (PACU) had care escalated to the ICU. No severe complications were identified after the PACU stay. During the next 48 hours after discharge, 4 (1.9%) patients returned to any emergency room to be evaluated without requiring readmission. CONCLUSION: Routine ICU admission following uncomplicated VSS is unnecessary. Overnight admission to a low-acuity ward, or even same-day discharge in select patients, appears to be a safe and cost-effective strategy.

The Possible Role of the Superior Sagittal Sinus in Regulating Cerebrospinal Fluid Dynamics among Preterm Infants: A Case Report and a Review of the Literature.

We report the case of a preterm of 27 weeks of gestation who developed posthemorrhagic ventricular dilatation associated to a complete thrombosis of the superior sagittal sinus, for its peculiar interest in clarifying the physiology of the cerebrospinal fluid (CSF) dynamics. The exact CSF volume that must be removed to improve cerebral hemodynamics and outcomes in infants with posthemorrhagic ventricular dilatation is unknown. According to Volpe's studies, a volume of 10 to 15 mL/kg/die of body weight is commonly chosen. The subject we report needed an excessive CSF drainage (up to 32 mL/kg/d), in presence of a functioning external ventricular drain. We review the literature on the topic, and we postulate that the superior sagittal sinus may play an active role in the CSF dynamics of the immature brain (as it happens for the adult brain).

Cerebral sinovenous thrombosis as a cause of subdural hemorrhage in the pediatric population: Is there a correlation?

PURPOSE: Cerebral sinovenous thrombosis is an increasingly recognized cause of stroke in children and neonates. Its true incidence appears to be underestimated. Despite being a rare event, certain studies have found a correlation between subdural hemorrhage and cerebral sinus thrombosis. The literature suggests that spontaneous cerebral sinovenous thrombosis in the pediatric population may lead to the occurrence of a subdural hemorrhage. In this report, we present a case of cerebral venous thrombosis associated with chronic subdural hematoma and review the literature to highlight the importance of these conditions. CASE REPORT: An 11-year-old boy was admitted in the neurosurgery department with headache and a neurological examination without changes. The imaging studies identified a heterogeneous subdural collection in the fronto-temporo-parietal region. The patient underwent surgical drainage of the subdural hematoma, and the procedure was performed without complications. The magnetic resonance and angiography showed an extensive thrombosis of the superior sagittal sinus, extending downward to the occipital sinus and partially to the right transverse sinus. CONCLUSIONS: Appropriate management in the diagnosis and an early treatment of dural sinus thrombosis associated with subdural hemorrhage can reduce the risk of recurrence and improve the clinical outcome.

A new classification of parasagittal bridging veins based on their configurations and drainage routes pertinent to interhemispheric approaches: a surgical anatomical study.

OBJECTIVE: Opening the roof of the interhemispheric microsurgical corridor to access various neurooncological or neurovascular lesions can be demanding because of the multiple bridging veins that drain into the sinus with their highly variable, location-specific anatomy. The objective of this study was to propose a new classification system for these parasagittal bridging veins, which are herein described as being arranged in 3 configurations with 4 drainage routes. METHODS: Twenty adult cadaveric heads (40 hemispheres) were examined. From this examination, the authors describe 3 types of configurations of the parasagittal bridging veins relative to specific anatomical landmarks (coronal suture, postcentral sulcus) and their drainage routes into the superior sagittal sinus, convexity dura, lacunae, and falx. They also quantify the relative incidence and extension of these anatomical variations and provide several preoperative, postoperative, and microneurosurgical clinical case study examples. RESULTS: The authors describe 3 anatomical configurations for venous drainage, which improves on the 2 types that have been previously described. In type 1, a single vein joins; in type 2, 2 or more contiguous veins join; and in type 3, a venous complex joins at the same point. Anterior to the coronal suture, the most common configuration was type 1 dural drainage, occurring in 57% of hemispheres. Between the coronal suture and the postcentral sulcus, most veins (including 73% of superior anastomotic veins of Trolard) drain first into a venous lacuna, which are larger and more numerous in this region. Posterior to the postcentral sulcus, the most common drainage route was through the falx. CONCLUSIONS: The authors propose a systematic classification for the parasagittal venous network. Using anatomical landmarks, they define 3 venous configurations and 4 drainage routes. Analysis of these configurations with respect to surgical routes indicates 2 highly risky interhemispheric surgical fissure routes. The risks are attributable to the presence of large lacunae that receive multiple veins (type 2) or venous complex (type 3) configurations that negatively impact a surgeon's working space and degree of movement and thus are predisposed to inadvertent avulsions, bleeding, and venous thrombosis.

Predictors of recurrence after surgical resection of parafalcine and parasagittal meningiomas.

PURPOSE: Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery. METHODS: This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence. RESULTS: A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10-71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan-Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60-8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16-7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38-6.96; p = 0.006) as independent factors that portend shorter time to recurrence. CONCLUSION: This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes.

[Comparison of methods of treatment of meningiomas invading the superior sagittal sinus]. / Sravnitel'naya otsenka metodov lecheniya meningiom, invaziruyushchikh verkhnii sagittal'nyi sinus.

There are various approaches to the treatment of patients with parasagittal meningiomas. OBJECTIVE: To optimize treatment strategy for meningiomas invading the superior sagittal sinus. MATERIAL AND METHODS: The study included 87 patients with benign parasagittal meningiomas between 2010 and 2012. Of these, 34 patients underwent surgery alone, 27 - radiotherapy, 26 - surgery and subsequent radiotherapy. Both groups were comparable in male-to-female ratio, age and localization of tumors in relation to superior sagittal sinus. The follow-up period was at least 5 years. We analyzed the effect of treatment on neurological status, Karnofsky score and tumor growth control. RESULTS: Mean volume of tumors was 43.3 cm3 in patients undergoing surgery and 6.7 cm3 in the radiotherapy group. In the combined treatment group, mean volume was 65.8 cm3 before surgery and 8.8 cm3 before irradiation. General cerebral symptoms (84%), epileptic seizures (37%) and movement disorders (31%) prevailed. Surgery provided the best results in patients with small meningiomas (<14 cm3) causing focal neurological symptoms. Isolated radiotherapy was the most effective in asymptomatic patients. Large tumors required surgery with adjuvant irradiation. CONCLUSION: Benign parasagittal meningiomas followed by focal neurological symptoms require surgical intervention regarding the best functional outcomes and tumor growth control. Radiotherapy without surgery is advisable for progressive asymptomatic tumors. Resection followed by irradiation is preferable if total resection without the risk of damage to veins and cortex is impossible.

Comparison of edoxaban and enoxaparin in a rat model of AlCl3-induced thrombosis of the superior sagittal sinus.

Cerebral sinus venous thrombosis (CSVT) is an uncommon disease that is usually treated with anticoagulation (heparin, low-molecular heparin, or vitamin K-antagonists). We compared treatment with edoxaban, an oral factor Xa-antagonist, that has not been approved in patients with CSVT, with enoxaparin, a well-established therapy, in a rat model of CSVT. Fifty male Wistar rats were randomized into 5 groups (10 animals each) and subjected to aluminum chloride (AlCl3)-induced thrombosis of the superior sagittal sinus (SSS) or sham procedure. Animals with thrombosis of the SSS were treated with edoxaban, enoxaparin, or placebo. Diagnostic workup included neurological examination, MRI imaging, MR-flow measurements of the SSS, and immunohistochemical staining. Neurological examination revealed no differences between treatment groups. Seven days after initial thrombosis, flow in the SSS was lower in the active treatment group as compared to sham-operated animals (p < 0.05). Flow in the SSS in the active treatment groups (edoxaban 1 h prior to thrombosis: 0.16 cm/s ± 0.06 cm/s; edoxaban 6 h after thrombosis: 0.13 cm/s ± 0.05 cm/s; enoxaparin: 0.13 cm/s ± 0.04 cm/s; placebo: 0.07 cm/s ± 0.02 cm/s) was higher as compared to placebo (p < 0.05), but there were no differences between the active treatment groups (p > 0.05). Immunohistochemical staining showed no differences in the actively treated animals. Edoxaban proved to be similar to enoxaparin in a model of experimental AlCl3-induced CSVT.

Doppler Ultrasound Flow Reversal in the Superior Sagittal Sinus to Detect Cerebral Venous Congestion in Vein of Galen Malformation.

BACKGROUND AND PURPOSE: Vein of Galen malformation is a rare congenital cerebrovascular malformation. In affected patients, increased cerebral venous pressure constitutes an important etiologic factor for the development of brain parenchymal damage. The aim of this study was to investigate the potential of serial cerebral venous Doppler measurements to detect and monitor increased cerebral venous pressure. MATERIALS AND METHODS: This was a retrospective monocentric analysis of ultrasound examinations within the first 9 months of life in patients with vein of Galen malformation admitted at <28 days of life. Categorization of perfusion waveforms in the superficial cerebral sinus and veins into 6 patterns was based on antero- and retrograde flow components. We performed an analysis of flow profiles across time and correlation with disease severity, clinical interventions, and congestion damage on cerebral MR imaging. RESULTS: The study included 44 Doppler ultrasound examinations of the superior sagittal sinus and 36 examinations of the cortical veins from 7 patients. Doppler flow profiles before interventional therapy correlated with disease severity determined by the Bicêtre Neonatal Evaluation Score (Spearman ρ = -0.97, P = < .001). At this time, 4 of 7 patients (57.1%) showed a retrograde flow component in the superior sagittal sinus, whereas after embolization, none of the 6 treated patients presented with a retrograde flow component. Only patients with a high retrograde flow component (equal or more than one-third retrograde flow, n = 2) showed severe venous congestion damage on cerebral MR imaging. CONCLUSIONS: Flow profiles in the superficial cerebral sinus and veins appear to be a useful tool to noninvasively detect and monitor cerebral venous congestion in vein of Galen malformation.

Absence of the torcular, review of venous sinus anatomy, and the simplified dural sinus classification.

BACKGROUND: Classically, the torcular Herophili is described as the symmetric junction between the superior sagittal sinus (SSS), transverse sinuses (TSs), and straight sinus (SS). However, finding this pattern in practice is not standard. Anatomical variations are common, and different drainage patterns should be expected. Existing literature proposes highly detailed descriptions and classifications of this region. Still, a simplified and practical categorization is not available. METHODS: We present an anatomical finding of the torcular Herophili discovered on a cadaveric dissection. Then, we conducted a retrospective study examining the 100 most recent cranial magnetic resonance venographies (MRVs) from the Mayo Clinic, labeling them with a new proposed dural sinus classification system. Images were initially classified by two authors and further validated by a board-certified neurosurgeon and a board-certified neuroradiologist from our institution. To measure consistency in image identification, two additional international neurosurgeons were asked to classify a subset of the same MRV images, and their answers were compared. RESULTS: Of the MRV cohort, 33 patients were male and 67 were female. Their ages ranged from 18 to 86 years, with a mean of 47.35 years and a median of 49 years. Upon examination, 53 patients presented as confluent (53%), 9 as SSS divergent (9%), 25 as SS divergent (25%), 11 as circular (11%), and 2 as trifurcated (2%). The inter-rater reliability ranked very good; agreement between the two neurosurgeons was 83% (κ = 0.830, p < 0.0005). CONCLUSION: The confluence of the venous sinuses is a highly variable anatomical area that is rarely evaluated with neuroimaging before surgery. The classic textbook configuration is not the rule. Using a simplified classification system may increase awareness and hopefully patient safety by preparing the physician for anatomical variations that they will encounter in a surgical or clinical scenario.

Assessment of Meningeal Lymphatics in the Parasagittal Dural Space: A Prospective Feasibility Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

OBJECTIVE: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. MATERIALS AND METHODS: Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. RESULTS: The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD wash-out rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040). CONCLUSION: This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.

Adaptative Diploic Vein Bypass of the Superior Sagittal Sinus in a Large Falcine Meningioma.

We describe an adaptative bypass at the posterior third of the superior sagittal sinus (SSS) through the parietal diploe veins related to a large falcine meningioma on a 55-year-old lady with progressive headaches and mild left hemiparesis. Cranial imaging revealed a large tumor at the posterior third of the cerebral falx, compatible with meningioma. Imaging also revealed lack of continuity of the superior sagittal sinus at that region. Large diploic veins were seen bypassing the segment of the SSS affected by the tumor. An "L"-shaped modified posterior interhemispheric craniotomy was performed to avoid traversing the diploic veins. Near-total resection of the meningioma was accomplished. Postoperative imaging revealed a small remnant invading the SSS, which was treated with adjuvant radiotherapy. The patient tolerated the procedure well and was discharged to rehabilitation unit on postoperative day 5 with no neurologic deficits.

Superior sagittal sinus flow as a proxy for tracking global cerebral blood flow dynamics during wakefulness and sleep.

Sleep, a state of reduced consciousness, affects brain oxygen metabolism and lowers cerebral metabolic rate of oxygen (CMRO2). Previously, we quantified CMRO2 during sleep via Fick's Principle, with a single-band MRI sequence measuring both hemoglobin O2 saturation (SvO2) and superior sagittal sinus (SSS) blood flow, which was upscaled to obtain total cerebral blood flow (tCBF). The procedure involves a brief initial calibration scan to determine the upscaling factor (fc), assumed state-invariant. Here, we used a dual-band sequence to simultaneously provide SvO2 in SSS and tCBF in the neck every 16 seconds, allowing quantification of fc dynamically. Ten healthy subjects were scanned by MRI with simultaneous EEG for 80 minutes, yielding 300 temporal image frames per subject. Four volunteers achieved slow-wave sleep (SWS), as evidenced by increased δ-wave activity (per American Academy of Sleep Medicine criteria). SWS was maintained for 13.5 ± 7.0 minutes, with CMRO2 28.6 ± 5.5% lower than pre-sleep wakefulness. Importantly, there was negligible bias between tCBF obtained by upscaling SSS-blood flow, and tCBF measured directly in the inflowing arteries of the neck (intra-class correlation 0.95 ± 0.04, averaged across all subjects), showing that the single-band approach is a valid substitute for quantifying tCBF, simplifying image data collection and analysis without sacrificing accuracy.

Primary Intracranial Ewing Sarcoma Invading the Superior Sagittal Sinus with EWSR1-FLI1 Gene Fusion and EWSR1 Gene Mutation: A Case Report and Literature Review.

BACKGROUND: Primary intracranial Ewing sarcoma (ES) is an extremely rare intracranial malignant tumor, mostly occurring in children and adolescents. Because of its rarity, the magnetic resonance imaging (MRI) features and treatment strategies of primary intracranial ES are still unclear. METHODS: The purpose of this study was therefore to report a case of primary intracranial ES, whose molecular features included both EWSR1-FLI1 (EWS RNA binding protein 1- Friend leukemia integration 1) gene fusion and EWSR1 gene mutation. It is worth noting that this is the first reported case of ES invading the superior sagittal sinus and mostly causing occlusion. At the same time, there were polymorphisms of four drug metabolism-related enzymes in the tumor. Subsequently, we conducted a literature review to characterize the clinical features, imaging findings, pathological features, treatments, and prognoses of primary intracranial ESs. RESULTS: A 21-year-old female was admitted to the hospital with headache with nausea and vomiting for 2 weeks. An MRI showed a 3.8 × 4.0 cm large heterogeneous mass in the bilateral parietal lobe with peritumoral edema. The tumor invaded the superior sagittal sinus and mostly caused occlusion of the middle segment of the superior sagittal sinus. The mass was successfully removed using a neuromicroscope. Postoperative pathology indicated a primary intracranial ES. High throughput sequencing (next generation sequencing) showed that there was EWSR1-FLI1 gene fusion and EWSR1 gene mutation in the tumor, with polymorphisms of four drug metabolism-related enzymes and low tumor mutational burden. Subsequently, the patient received intensity modulated radiation therapy. The patient has signed an informed consent form. CONCLUSIONS: The diagnosis of primary intracranial ES depended on histopathology, immunohistochemistry staining, and genetic testing. At present, total tumor resection combined with radiotherapy and chemotherapy is the most effective treatment. We report the first case of primary intracranial ES invading the superior sagittal sinus and causing middle segment occlusion, accompanied by EWSR1-FLI1 gene fusion and EWSR1 gene mutation.

Investigating the hemodynamic implications of triangular cross-sectioned superior sagittal sinus vessels and the errors associated with idealised modelling.

The superior sagittal sinus (SSS) is a blood vessel that is often observed to be approximately triangular in cross-section, due to how the venous wall attaches to the surrounding tissue. Despite this, the vessel has been assumed to be circular, when models are generated without patient-specific data. In this study, the differences between the cerebral hemodynamics of one circular, three triangular and five patient-specific cross-sectional models of a SSS were conducted. The errors associated with using circular cross-sectioned flow extensions were also determined. Computational fluid dynamics (CFD) models were generated from these geometries, with a population mean transient blood flow profile incorporated. The maximal helicity of the fluid flow was found to be elevated in the triangular cross-section, compared to the circular, with a higher wall shear stress (WSS) observed over a smaller, more concentrated region on the posterior sinus wall. The errors associated with using a circular cross-section were detailed, with the cross-sectional area appearing to have a greater influence on the hemodynamic parameters than the triangularity or circularity of the cross-section. This highlighted the importance of exhibiting caution when incorporating idealised modelling, especially when commenting on the true hemodynamics of these models. Errors were also found to be induced when using a circular cross-sectioned flow extension, for a geometry which was non-circular. This study highlights the importance of understanding the human anatomy when modelling blood vessels.

Infectious thrombosis of the superior sagittal sinus with subarachnoid hemorrhage: A case report.

RATIONALE: Cerebral venous sinus thrombosis (CVST) represents 0.5% to 1% of all strokes. CVST can cause headaches, epilepsy, and subarachnoid hemorrhage (SAH). CVST is easily misdiagnosed because of the variety and non-specificity of symptoms. Herein, we report a case of infectious thrombosis of the superior sagittal sinus with SAH. PATIENT CONCERNS: A 34-year-old man presented to our hospital with a 4-hour history of sudden and persistent headache and dizziness with tonic convulsions of the limbs. Computed tomography revealed SAH with edema. Enhanced magnetic resonance imaging showed an irregular filling defect in the superior sagittal sinus. DIAGNOSES: The final diagnosis was hemorrhagic superior sagittal sinus thrombosis and secondary epilepsy. INTERVENTIONS: He was treated with antibiotic, antiepileptic, fluids to rehydrate, and intravenous dehydration. OUTCOMES: After treatment, the seizures did not recur and the symptoms were relieved. One month after the antibiotic treatment, the muscle strength of the patient's right extremity was restored to level 5, and there was no recurrence of his neurological symptoms. LESSONS: We describe a case of infectious thrombosis of the superior sagittal sinus manifested as SAH, which is easily misdiagnosed, especially when patients present with an infection. Clinicians must therefore take care during the diagnosis and selection of the treatment strategy.

Nailed Through Superior Sagittal Sinus: A Case Report and Surgical Considerations.

BACKGROUND AND IMPORTANCE: We report a case of nail gun-related penetrating brain injury, puncturing through the anterior third of superior sagittal sinus, which remained patent and was associated with an arteriovenous (AV) shunt revealed on catheter angiogram. CLINICAL PRESENTATION: A previously well 35-year-old male patient presented with a self-inflicted pneumatic nail gun injury. Neurological examination was unremarkable. Computed tomography (CT) of the brain demonstrated the nail had penetrated through the skull, traversed the anterior third of the superior sagittal sinus (SSS), right frontal lobe parenchyma, frontal horn of right lateral ventricle, caudate, and right cerebral peduncle. CT angiogram showed no associated vascular injury, with CT venogram showing a short segment of filling defect within SSS adjacent to nail penetration. However, digital subtraction angiography revealed an associated arteriovenous shunt 8 mm anterior to the dural penetration site, which filled the SSS in arterial phase. Removal of the nail was performed using a double concentric craniotomy around the nail entry site. Before removal of the nail, the SSS anterior to the nail penetration site was tied off and divided along with coagulation and division of the falx, while the SSS posterior to the nail penetration site was also tied off to isolate the penetrated SSS segment. The patient recovered well with repeat digital subtraction angiography demonstrating no residual AV shunting. CONCLUSION: This case report aims to highlight the importance of performing a catheter angiogram and describe our stepwise considerations and approach in treating a penetrating injury involving the superior sagittal sinus with concurrent AV fistula.