Unilateral hypoplasia of the rostral end of the superior sagittal sinus

Unmasking hidden risks: cerebral venous sinus thrombosis and spontaneous subdural hematoma in women on oral contraceptives - insights from a case report and systematic literature review

BACKGROUND AND OBJECTIVE

Cerebral venous thrombosis (CVT) is a rare but critical condition, particularly in young women, often linked to oral contraceptive use. It can lead to complications like subdural hematoma (SH), which are challenging to diagnose and manage. We report the case of a 39-year-old woman who presented with severe headaches and neurological symptoms, leading to a diagnosis of chronic SH and CVT, associated with long-term oral contraceptive use. This case is unique as it documents the first known instance of chronic SH associated with CVT induced by oral contraceptives. Our objective was to explore this association using the Bradford Hill criteria and to review the diagnostic and therapeutic challenges of CVT and SH in this population.

METHODS

We conducted a systematic literature review adhering to PRISMA guidelines, focusing on SH cases linked to CVT in women using oral contraceptives.

RESULTS

Including our case, four cases of SH associated with CVT secondary to oral contraceptive use were identified. Common symptoms included severe headache and neurological deficits. All patients received anticoagulation therapy, with surgical intervention required in severe cases. Prognosis was generally favorable with appropriate management.

CONCLUSION

This case emphasizes the importance of considering CVT in women presenting with spontaneous SH, particularly those on oral contraceptives. Early diagnosis, careful clinical and radiological monitoring, and timely surgical intervention are crucial for optimal outcomes.

Cerebral Sinus Hemodynamics in Adults Revealed by 4D Flow MRI

BACKGROUND

The hemodynamics of the cerebral sinuses play a vital role in understanding blood flow-related diseases, yet the hemodynamics of the cerebral sinuses in normal adults remains an unresolved issue.

PURPOSE

To evaluate hemodynamics in the cerebral sinus of adults using 4-dimensional flow MRI (4D Flow MRI).

STUDY TYPE

Cross-sectional.

POPULATION

Ninety-nine healthy volunteers (mean age, 42.88 ± 13.16 years old; females/males, 55/44).

FIELD STRENGTH/SEQUENCE

3 T/4D Flow MRI.

ASSESSMENT

The blood flow velocity, average blood flow rate (Q), and vortexes at the superior sagittal sinus (SSS), straight sinus (STS), transverse sinus, sigmoid sinus, and jugular bulb of each volunteer were evaluated by two independent neuroradiologists. The relationship between the total cerebral Q and sex and age was also assessed. Twelve volunteers underwent two scans within a month.

STATISTICAL TESTS

The intraclass correlation coefficient (ICC) evaluated the inter-observer agreement. Blood flow parameters among volunteers were compared by the independent-sample t-test or Mann-Whitney U test. The multiple linear regression equation was used to evaluate the relationship between total cerebral Q and age and sex. P < 0.05 indicated statistical significance.

RESULTS

The test-retest and interobserver reliability of average velocity and Q were moderate to high (ICC: 0.54-0.99). Cerebral sinus velocity varied by segment and cardiac cycle. The SSS's velocity and Q increased downstream and Q near torcular herophili was 3.5 times that through the STS. The total cerebral Q decreased by 0.06 mL/s per year (β = -0.06 ± 0.013) and was sex-independent within the group. Vortexes were found in 12.12%, 8.9%, and 59.8% of torcular herophili, transverse-sigmoid junction, and jugular bulb, respectively, and were related to higher upstream flow.

DATA CONCLUSION

Cerebral sinuses could be measured visually and quantitatively in vivo by 4D Flow MRI, providing a basis for future research on pulsating tinnitus, multiple sclerosis, and other related diseases.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

Morphometric CT angiographic study of the SSS and its adjacent structures: A comparative analysis between elderly and nonelderly individuals of a Han Chinese population

Objective

The superior sagittal sinus (SSS) is an important structure, but few studies have analyzed it using computed tomography angiography (CTA).

Methods

This study was performed to examine the angiographic anatomy of the SSS and its adjacent structures using CTA in Han Chinese participants. According to age, participants were divided into elderly and nonelderly groups. The parameters of the SSS and adjacent structures were measured, recorded and analyzed statistically.

Results

A total of 500 Han Chinese participants were enrolled in this study, including 346 in the elderly group and 154 in the nonelderly group. In the elderly group, regarding inferior sagittal sinus (ISS) development, 187 ISSs were absent, 85 were visible, and 74 were clear. In the nonelderly group, 62 ISSs were absent, 54 were visible, and 38 were clear. In the elderly group, the Rolandic bridging vein diameter was 3.6 ± 0.8 mm; in the nonelderly group, the diameter was 3.9 ± 1.1 mm. The statistical results showed a difference in ISS development between the elderly and nonelderly groups (P < 0.05). The relationship of age with ISS development was assessed using linear regression analysis, and the results indicated that ISS became gradually occluded with age (P < 0.05). The statistical results also showed a difference in the Rolandic bridging vein diameter between the elderly and nonelderly groups (P < 0.05). The relationship of age with the Rolandic bridging vein diameter was assessed using linear regression analysis, and the results indicated that the Rolandic bridging vein tended to become thinner with age (P < 0.05).

Conclusion

This study found that more ISSs may become occluded and that the Rolandic bridging vein may become thinner with age. Other parameters of the SSS and its adjacent structures may not be affected by aging. In addition, our study also provided normal CTA parameters of the SSS and its adjacent structures in Han Chinese people.

Angioarchitecture of the hemorrhagic developmental venous anomaly with stenosis of the collecting vein and cavernous malformation: a case report

We herein report a case of developmental venous anomaly (DVA) with venous congestion caused by stenosis of the collecting vein that presented with intracerebral hemorrhage (ICH). A 74-year-old woman was referred to our hospital a few days after the onset of motor aphasia. Computed tomography (CT) and magnetic resonance imaging (MRI) showed ICH in the left frontal lobe. Angiography revealed DVA in the left frontal lobe in the late venous phase. Stenosis of the collecting vein of DVA at the entrance to the superior sagittal sinus was detected and accompanied by cavernous malformation (CM) beside DVA. Cone-beam CT revealed the absence of the left septal vein and hypoplastic transverse caudate veins. The patient was treated by blood pressure management and no additional neurological symptoms were detected. DVA develops to compensate for the absence of pial or deep venous systems, and generally benign and clinically asymptomatic. However, the outflow restriction of DVA causes chronic venous hypertension and the formation of CM. These abnormalities are considered to occur during post-natal life and may result in ICH. The risk of hemorrhage needs to be considered in cases of DVA with restricted venous outflow or CM.

Spontaneous chronic subdural haematoma due to hypoplastic rostral superior sagittal sinus

The superior sagittal sinus (SSS) is a midline structure of the superficial cerebral venous system that drains the anterior cerebral hemispheres. Hypoplasia of the rostral SSS is a known variant, although associated complications are rare. A woman in her 30s presented for evaluation of a symptomatic left-sided acoustic neuroma and was found to have an incidental chronic subdural haematoma (SDH) over the left frontoparietal convexity without trauma or precipitating event. The SDH expanded on serial imaging and the patient eventually underwent left-sided frontoparietal craniotomy for haematoma evacuation. Haematological evaluation was benign, but angiography revealed absence of the anterior half of the SSS. We report the first case of spontaneous SDH in the setting of hypoplastic rostral SSS.

Anatomy imaging and hemodynamics research on the cerebral vein and venous sinus among individuals without cranial sinus and jugular vein diseases

In recent years, imaging technology has allowed the visualization of intracranial and extracranial vascular systems. However, compared with the cerebral arterial system, the relative lack of image information, individual differences in the anatomy of the cerebral veins and venous sinuses, and several unique structures often cause neurologists and radiologists to miss or over-diagnose. This increases the difficulty of the clinical diagnosis and treatment of cerebral venous system diseases. This review focuses on applying different imaging methods to the normal anatomical morphology of the cerebral venous system and special structural and physiological parameters, such as hemodynamics, in people without cranial sinus and jugular vein diseases and explores its clinical significance. We hope this study will reinforce the importance of studying the cerebral venous system anatomy and imaging data and will help diagnose and treat systemic diseases.

Angiographic classification of the inferior sagittal sinus based on the venous drainage patterns

PURPOSE

The inferior sagittal sinus (ISS) and its tributaries have received little attention because of its inconspicuous appearance, and its anatomical variations are also unknown. This study aimed to evaluate the morphological variations of the ISS.

MATERIALS AND METHODS

We retrospectively reviewed 518 patients in whom cerebral angiography was clinically indicated. The detailed angioarchitecture of the cerebral venous system, including the ISS and their tributaries, and the morphological variations of the ISS were evaluated. Abnormalities of the rostral third superior sagittal sinus (SSS) were also evaluated.

RESULTS

The ISS was visualized in 270 (52.1%) patients. We proposed an angiographic ISS classification according to the venous drainage patterns: Type 0, not visualized; Type 1, small ISS with faint tributaries; Type 2, moderate ISS with developed tributaries; and Type 3: large ISS with well-developed tributaries, which are responsible for the venous drainage of the anterior frontal lobe. The frequency of each ISS type was as follows: Type 0, 248 (47.9%); Type 1, 211 (40.7%); Type 2, 44 (8.5%); and Type 3, 15 (2.9%). The mean ISS size was significantly larger with an increase in the type of ISS (p < 0.0001). The rostral third SSS hypoplasia was observed in all cases of Type 3. The hypoplasia of the rostral third SSS and development of the ISS were strongly correlated and complementary to each other.

CONCLUSION

This study provided the angiographic ISS classification, and our proposed angiographic ISS classification could be helpful in better understanding of the ISS anatomy and its venous drainage pattern.

[Thrombosis and anatomic variants of intracranial dural venous sinuses]

A rather large number of different anatomic variants of intracranial dural venous sinuses are known, and they are found so often that interpreting them only as anomalies is unlikely, except for variations such as sinus aplasia or doubling, which can be attributed to anomalies of the venous system. Diameter reduction (hypoplasia) of the transverse and sigmoid sinuses is observed relatively often. In cases of dural sinuses anomalies, sinuses on the contralateral side are necessarily evaluated as the main source of compensation. When diagnosing dural sinus thrombosis, it is necessary to have a clear idea of the structure of the cerebral venous system, so as not to mistakenly accept hypoplasia or sinus aplasia for thrombosis. Our own experience is based on the results of a neuroimaging study of cerebral veins and venous sinuses in 103 patients (average age 35±10 years) with a tension-type headache. Hypoplasia of the transverse and sigmoid sinuses was detected in 21 (22.4%) cases. In 10 cases (6 men, 4 women), a connection was established between hypoplasia of the dural sinuses and thrombosis. Four patients, presented with hypoplasia of the right transverse and sigmoid sinuses and 6 patients with hypoplasia of the left transverse and sigmoid sinuses. Thrombosis developed on the side of sinus hypoplasia (9 patients) or on the contralateral side (1 patient). Early diagnosis of cerebral venous thrombosis is crucial because the use of anticoagulants reduces the risk of a poor prognosis, severe disability without an additional increase in the risk of brain hematomas progression.

Incidentally detected total agenesis of the falx cerebri: Potential significance of this rare finding

Absence of the falx cerebri is a rare radiological finding, which is generally described in relation with varying degrees of holoprosencephaly or other structural central nervous system anomalies. We present a case of non-syndromic, asymptomatic absence of falx cerebri in an elderly patient, which was discovered incidentally on a computed tomography examination of the head. The superior sagittal sinus was narrowed, but present. Relevant anatomic and embryological considerations are discussed, as well as potential implications for clinical practice.

Cerebrospinal fluid spaces between intracranial venous sinuses and overlying dura mater: magnetic resonance imaging

Purpose The intracranial venous sinuses are thought to lie interdurally, circumferentially contacting the dura maters. There has been no report documenting the cerebrospinal fluid spaces intervening between the venous sinuses and overlying dura mater. Here, we explored such structures using magnetic resonance imaging. Methods A total of 206 patients underwent magnetic resonance imaging with a T2-weighted or constructive interference steady-state sequence. Imaging data were analysed on a workstation. Results The peri-superior sagittal sinus cerebrospinal fluid spaces were identified in 100% of 133 patients who underwent coronal and sagittal T2-weighted imaging and in 98.6% of 73 with a constructive interference steady-state sequence. Among the 205 patients, the cerebrospinal fluid spaces were distributed over the frontoparietal region in 84% and the parietal region in 16%. On sagittal sections performed for 58 patients, the cerebrospinal fluid spaces were identified between the superior sagittal sinus and overlying dura mater. The peri-sinus spaces were found in 91% of the identified transverse sinuses, 29% of the straight and 70% of the occipital sinuses. The peri-superior sagittal sinus cerebrospinal fluid spaces were classified into five distinct appearances. The circumferential type was the most predominant and was found in 68.7%, followed by lateral in 10.2%, lateral plus inferior in 7.5%, lateral plus superior in 6.8% and superior in 6.8%. Conclusions The intracranial venous sinuses do not circumferentially contact with the dura maters. Instead, they are adjacent to the cerebrospinal fluid spaces intervening between the walls and overlying dura maters. These spaces are critical when considering tumour extensions contralateral to the superior sagittal sinus and safe surgical manoeuvres around it.

Anatomical Variations of Brain Venous Sinuses in Patients with Arteriovenous Malformations: Incidental Finding or Causative Factor?

OBJECTIVE

Acquired anomalies of the dural venous sinuses (DVS) have been correlated extensively with the development of dural arteriovenous fistulas (DAVFs). Despite the known similarities of DAVFs' pathogenesis with that of arteriovenous malformations (AVMs), the relationship of venous sinuses anomalies with AVMs scarcely has been studied. We aimed to investigate whether patients with AVM show a greater prevalence of congenital DVS anomalies. We hypothesized that these congenital anomalies trigger AVM development during early childhood just as acquired DVS anomalies trigger DAVFs formation during adulthood.

METHODS

Angiographic anomalies of the brain venous sinuses were studied in a cohort of 45 consecutive patients with AVM and compared with the angiographic; venous sinus anomalies of a control group formed by a second consecutive; series of 45 patients with subarachnoid hemorrhage.

RESULTS

Congenital anomalies of any DVS were more frequent in patients with AVM than in the control group (49.8% vs. 22.2%; P = 0.015). Congenital abnormalities of the superior sagittal sinus not only were more frequent in patients with AVM (27% vs. 6.7%; P = 0.021) but seemed also related to the AVM location: in 5 of the 6 AVM cases with unilateral superior sagittal sinus aplasia, the AVM was ipsilateral to the venous anomaly.

CONCLUSIONS

Patients with AVM have a greater likelihood of congenital anomalies of any DVS. These anomalies seem to be related also to the AVM location. These findings suggest that congenital anomalies of DVS may be related to the development of AVMs.

The missing falx: a potential surgical pitfall during interhemispheric transcallosal approach

One of the standard surgical approaches to lateral ventricular tumors involves interhemispheric dissection along the falx cerebri. The falx cerebri thus provides an important landmark in guiding the surgeon to the midline. Unrecognized absence of falx may lead to surgical complications. A child with tuberous sclerosis presented with refractory epilepsy and a lateral ventricular tumor. The tumor was excised by an interhemispheric trans-callosal approach. The midline falx cerebri was absent anteriorly, rendering the identification of midline difficult. The embryology of a deficient falx and its surgical implications are discussed in this short report.

Normal neuroanatomical variants that may be misinterpreted as disease entities

Variations of normal development and benign incidental anomalies are frequently observed on diagnostic neuroimaging. It is important these are recognised for what they are, as misinterpretation may result in unnecessary further investigation, follow-up imaging and anxiety. In this article, we review benign intracranial anomalies commonly referred to our unit for specialist neuroradiology advice or multidisciplinary discussion, concerning cysts of the pineal gland and pituitary fossa, vascular anomalies, and perivascular spaces. This article outlines the embryology and development, the various imaging features as well as the clinical relevance and differential diagnoses of each normal neuroanatomical variant.

Anatomical Variations of Cerebral MR Venography: Is Gender Matter?

Purpose

Knowledge of variations in the cerebral dural venous sinus anatomy seen on magnetic resonance (MR) venography is essential to avoid over-diagnosis of cerebral venous sinus thrombosis (CVST). Very limited data is available on gender difference of the cerebral dural venous sinus anatomy variations.

Materials and Methods

A retrospective study was conducted to study the normal anatomy of the intracranial venous system and its normal variation, as depicted by 3D MR venography, in normal adults and any gender-related differences.

Results

A total of 1654 patients (582 men, 1072 women, age range 19 to 86 years, mean age: 37.98±13.83 years) were included in the study. Most common indication for MR venography was headache (75.4%). Hypoplastic left transverse sinus was the most common anatomical variation in 352 (21.3%) patients. Left transverse sinus was hypoplastic in more commonly in male in comparison to female (24.9% versus 19.3%, p = 0.009). Most common variation of superior sagittal sinus (SSS) was atresia of anterior one third SSS (15, 0.9%). Except hypoplastic left transverse sinus, rest of anatomical variations of the transverse and other sinuses were not significantly differ among both genders.

Conclusion

Hypoplastic left transverse sinus is the most common anatomical variation and more common in male compared to female in the present study. Other anatomical variations of dural venous sinuses are not significantly differ among both genders.

A possible venous connection between the cranial and nasal cavity

PURPOSE

The foramen cecum (FC) is a fine bony canal with the aperture located immediately anterior to the crista galli (CG). The venous structures in the regions of the FC and CG have been inconsistently described and are not well understood. Here we explore these veins using magnetic resonance imaging.

MATERIALS AND METHODS

We enrolled 101 patients who underwent contrast examinations and exhibited intact skin, skull, dura mater, and intracranial dural sinuses. Imaging data were obtained as thin-sliced, seamless sagittal sections and were transferred to a workstation for analysis.

RESULTS

In 84 % of the patients, tubular-shaped venous extensions arose from the rostral end of the falx cerebri and were confirmed to lie in the FC. These extensions were supplied by the superior sagittal sinus or the frontal cortical vein, and were classified into four types: rudimental slight projections, short and straight extensions, long and straight channels, and long and tortuous channels. Furthermore, 27.7 % of the patients exhibited a distinct venous channel between the venous extension in the FC and the median vestibular submucosa of the nasal cavity. Among these channels, 81.5 % were connected to the vein lying in the FC via a short channel that vertically pierced the CG.

CONCLUSIONS

The FC contains tubular-shaped venous extensions that are supplied by the rostral end of the superior sagittal sinus or the frontal cortical vein. The cranial cavity, FC, and nasal cavity may be connected by a venous channel.

Whole-Brain Computed Tomographic Perfusion Imaging in Acute Cerebral Venous Sinus Thrombosis

BACKGROUND

Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood.

SUMMARY

We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced.

KEY MESSAGES

Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction.

Total agenesis of superior sagittal sinus and falx cerebri in a patient who has a subacute subdural hematoma crossing midline: case report

BACKGROUND AND IMPORTANCE

Anatomic variations of the superior sagittal sinus (SSS) and falx cerebri (FC) are uncommon in that agenesis of these structures is extremely rare. We report an extremely rare anatomic variation, total agenesis of the SSS and FC, and briefly discuss it from the anatomical, embryological, radiological, and clinical perspectives.

CLINICAL PRESENTATION

A 49-year-old woman presented with long-standing headache, gait disturbance, and nausea. Imaging studies showed a bilateral subdural hematoma crossing the midline, dilated venous structures, and perineural cysts, but SSS and FC. Following right-sided hemiparesis and consciousness disturbances, the subdural hematoma was evacuated from a left-sided parietal burr hole because of thick hematoma in this side. After the surgical evacuation, the hemiparesis and consciousness disturbances were regressed; however, she still had severe headache. On account of ongoing headaches and related imaging findings, it was thought that she had possible spontaneous intracranial hypotension. She was treated with autologous epidural blood patch and recovered well.

CONCLUSION

Agenesis of the SSS and FC are extremely rare variations. Agenesis of the SSS results in development of alternative venous pathways and may lead to misdiagnosis as dural arteriovenous fistulas. Agenesis of FC may cause diagnostic confusion, because subdural pathologies such as hematomas can cross the midline in rare occasions.