To determine a rapid and accurate method for locating the keypoint and \"keyhole\" in the suboccipital retrosigmoid keyhole approach. (1) Twelve adult skull specimens were selected to locate the anatomical landmarks on the external surface of the skull.The line between the infraorbital margin and superior margin of the external acoustic meatus was named the baseline. A coordinate system was established using the baseline and its perpendicular line through the top point of diagastric groove.The perpendicular distance (x), and the horizontal distance (y) between the central point of the \"keyhole\" and the top point of the digastric groove in that coordinate system were measured. The method was applied to fresh cadaveric specimens and 53 clinical cases to evaluate its application value. (1) x and y were 14.20 ± 2.63 mm and 6.54 ± 1.83 mm, respectively (left) and 14.95 ± 2.53 mm and 6.65 ± 1.61 mm, respectively (right). There was no significant difference between the left and right sides of the skull (P > 0.05). (2) The operative area was satisfactorily exposed in the fresh cadaveric specimens, and no venous sinus injury was observed. (3) In clinical practice, drilling did not cause injury to venous sinuses, the mean diameter of the bone windows was 2.0-2.5 cm, the mean craniotomy time was 26.01 ± 3.46 min, and the transverse and sigmoid sinuses of 47 patients were well-exposed. We propose a \"one point, two lines, and two distances\" for \"keyhole\" localization theory, that is we use the baseline between the infraorbital margin and superior margin of the external acoustic meatus and the perpendicular line to the baseline through the top point of the digastric groove to establish a coordinate system. And the drilling point was 14.0 mm above and 6.5 mm behind the top point of the digastric groove in the coordinate system.

BACKGROUND: Sigmoid sinus wall dehiscence can lead to pulsatile tinnitus with a significant decrease in quality of life, occasionally leading to psychiatric disorders. Several surgical and endovascular procedures have been described for resolving dehiscence. Within endovascular procedures, the sagittal sinus approach could be a technical alternative for tracking and accurate stent positioning within the sigmoid sinus when the jugular bulb anatomy is unfavorable.
METHODS: A retrospective case series of three patients with pulsatile tinnitus due to sigmoid sinus wall dehiscence without intracranial hypertension was reviewed from January 2018 to January 2022. From the participants enrolled, the median age was 50.3 years (range 43-63), with 67% self-identifying as female and 33% as male. They self-identified as Hispanic. Sigmoid sinus dehiscence was diagnosed using angiotomography, and contralateral transverse sinus stenosis was observed in all patients. Patients underwent surgery via a navigated endovascular sagittal sinus approach for sigmoid sinus stenting. No neurological complications were associated with the procedure. Pulsatile tinnitus improved after the procedure in all patients.
CONCLUSIONS: Superior sagittal sinus resection for sigmoid sinus wall stenting is a safe and effective technique. Pulsatile tinnitus due to sigmoid sinus wall dehiscence could be treated using the endovascular resurfacing stenting technique. However, further research is needed to evaluate the potential benefit of contralateral stenting for removing sinus dehiscence when venous stenosis is detected. However, resurfacing sigmoid sinus wall dehiscence results in symptomatic improvement.

OBJECTIVE: To identify the factors associated with venous collaterals in Thai patients with cerebral venous thrombosis.
METHODS: This retrospective 20-year cohort study enrolled patients diagnosed with cerebral venous thrombosis between January 2002 and December 2022. Data was collected from the electronic medical record, and venous collaterals were independently reviewed by two neuroradiologists using the Qureshi classification. Patients with and without venous collaterals were compared. Significant factors (P<0.05) in the univariate analysis were recruited into the multivariate logistic regression analysis to determine independently associated factors.
RESULTS: Among 79 patients with cerebral venous thrombosis, the prevalence of venous collaterals at the initial neuroimaging was 25.3%. In the univariate analysis, patients with cerebral venous thrombosis and venous collaterals were significantly younger (37.0±13.9 years vs. 44.9±17.4 years, P = 0.048), more often had occlusion in the superior sagittal sinus (80.0% vs. 54.2%, P = 0.041), and were associated with hormonal exposure (35.0% vs. 6.8%, P = 0.002). Multivariate logistic regression analysis revealed occlusion in the superior sagittal sinus (adjusted odds ratio [aOR] 3.581; 95% confidence interval [95% CI] 1.941-13.626; P = 0.044) and hormonal exposure (aOR 7.276, 95% CI 1.606-32.966, P = 0.010) as independent factors associated with venous collaterals in cerebral venous thrombosis.
CONCLUSIONS: In this cohort, the prevalence of venous collaterals was 25.3%. Occlusion in the superior sagittal sinus and hormonal exposure were independently associated with venous collaterals in patients with cerebral venous thrombosis.

BACKGROUND: Dural arteriovenous fistulae (dAVF) are relatively infrequently encountered, and status epilepticus (SE) and lateralised periodic discharges (LPDs) on electroencephalography (EEG) have only rarely been associated with these arteriovenous malformations.
METHODS: We present a patient with recurrent presentations with focal SE, aphasia and other focal deficits of cortical function and ictal and peri-ictal LPDs on serial EEG, who was shown to have a left hemispheric dAVF associated with left transverse and sigmoid sinus thrombosis. Seizures proved refractory to four anti-seizure medications but became more amenable to control after successful embolisation of the dAVF, with subsequent resolution of the focal cortical deficits. We discuss the co-occurrence of SE and LPDs with dAVF and review previously reported cases with this rare association.
CONCLUSIONS: Our report supports a causative relationship between dAVF and focal SE, manifesting as ictal LPDs on EEG, and highlights the importance of active dAVF management in achieving seizure control. The relatively good patient outcome contrasts to the few similar case reports. Whilst rare, it is important to consider dAVF as a potentially treatable condition underlying new-onset seizures, including SE.

Cerebral venous thrombosis is a rare cause of stroke in young mostly female adults which is frequently overlooked due to its variable clinical and radiological presentation. This review summarizes current knowledge on it risk factors, management and outcome in adults and highlights areas for future research. Females are 3 times more commonly affected and are significantly younger than males. The presenting symptoms can range from headache to loss of consciousness. However, the often-nebulous nature of symptoms can make the diagnosis challenging. Magnetic resonance imaging with venography is often the diagnostic imaging of choice. While unfractionated or low molecular-weight heparin is the mainstay of treatment, endovascular intervention with thrombolysis or thrombectomy and decompressive craniectomy may be required depending on clinical status. Nevertheless, approximately 80% of patients have a good recovery but mortality rates of -5% to 10% are not uncommon. Diagnosing cerebral venous thrombosis can be challenging but with vigilance and expert care patients have the best chance of a good clinical outcome.

BACKGROUND: Cerebral venous sinus thrombosis (CVST) is typically associated with a prothrombotic state of the blood, with its causative factors varying widely. Prior research has not reported the simultaneous occurrence of CVST and dural arteriovenous fistulas (DAVFs) as potentially resulting from genetic mutations. In this case report, we introduce a unique occurrence wherein a patient with a heterozygous mutation of the low-density lipoprotein receptor (LDLR) gene presented with CVST in conjunction with DAVFs.
METHODS: Presentation: A male patient, aged 51, sought treatment at our facility due to a consistent decline in cognitive functions accompanied by recurrent headaches. Comprehensive evaluations were administered, including neurological examinations, laboratory tests, magnetic resonance imaging, digital subtraction angiography, and whole exome sequencing. Digital subtraction angiography identified DAVFs in the patient\'s right sigmoid sinus and an occlusion within the left transverse sinus. The whole exome sequencing of blood samples pinpointed a heterozygous mutation in the LDLR gene (NM_000527:exon12:c.C1747T:p.H583Y). Following the confirmed diagnosis of CVST and DAVFs, the patient underwent anticoagulant therapy combined with endovascular procedures - these comprised embolization of the arteriovenous fistula in the right sigmoid sinus and balloon dilation with stent implantation in the left transverse sinus. A six-month follow-up indicated a significant abatement in the patient\'s symptoms.
CONCLUSIONS: This report marks the first documented case of an LDLR gene mutation that could be associated with the onset of CVST and DAVFs. The mutation in the LDLR gene might foster a prothrombotic environment, facilitating the gradual emergence of CVST and the subsequent genesis of DAVFs.

Mucopolysaccharidosis I-Hurler (MPSIH) syndrome is the most severe form of a group of hereditary lysosomal diseases. This study aims to describe previously unreported common cranial findings of sigmoid sinus stenosis with prominent emissary veins in MPSIH. A retrospective review was conducted of 66 patients with MPSIH who were treated at our institution. A total of 12 cranial MR imaging studies from 12 different patients demonstrating the venous sinus anatomy were reviewed. All 12 patients exhibited various degrees of sigmoid or transverse sinus stenosis. Eleven had various forms of emissary veins. Of those 12 patients with imaging of the venous sinuses, 9 had a lumbar puncture within the same months as the acquisition of the venogram without any correlation between elevated opening pressure and the severity of the venous sinus stenosis. Stenotic cerebral venous sinuses with associated emissary veins, common in patients with MPSIH, may be abnormal findings due to posterior fossa horns from glycosaminoglycan depositions rather than signs of elevated intracracranial pressure or requirement of CSF diversion.

OBJECTIVE: There has been limited literature regarding the bridging veins (BVs) of the medulla oblongata around the foramen magnum (FM). The present study aims to analyze the normal angioarchitecture of the BVs around the FM using slab MIP images of three-dimensional (3D) angiography.
METHODS: We collected 3D angiography data of posterior fossa veins and analyzed the BVs around the FM using slab MIP images. We analyzed the course, outlet, and number of BVs around the FM. We also examined the detection rate and mean diameter of each BV.
RESULTS: Of 57 patients, 55 patients (96%) had any BV. The median number of BVs was two (range: 0-5). The BVs originate from the perimedullary veins and run anterolaterally to join the anterior condylar vein (ACV), inferior petrosal sinus, sigmoid sinus, or jugular bulb, inferolaterally to join the suboccipital cavernous sinus (SCS), laterally or posterolaterally to join the marginal sinus (MS), and posteriorly to join the MS or occipital sinus. We classified BVs into five subtypes according to the draining location: ACV, jugular foramen (JF), MS, SCS, and cerebellomedullary cistern (CMC). ACV, JF, MS, SCS, and CMC BVs were detected in 11 (19%), 18 (32%), 32 (56%), 20 (35%), and 16 (28%) patients, respectively. The mean diameter of the BVs other than CMC was 0.6 mm, and that of CMC BV was 0.8 mm.
CONCLUSIONS: Using venous data from 3D angiography, we detected FM BVs in most cases, and the BVs were connected in various directions.

OBJECTIVE: This study was performed to investigate the dynamics of intracranial pressure (ICP) alterations and bilateral transverse-sigmoid sinus morphologies in patients with venous pulsatile tinnitus (PT).
METHODS: This retrospective study involved 27 patients with venous PT associated with sigmoid sinus wall anomalies. ICP and ICP metrics were measured by cerebrospinal fluid manometry and internal jugular vein compression tests. Correlation analysis was performed to determine the statistical correlation between ICP and the morphological metrics.
RESULTS: The mean ICP was 212.5 ± 47.3 mmH2O. The median ΔICPtotal was 130 (range, 55-150) mmH2O. The ΔICPtotal was linearly correlated with the open lumbar pressure, and a significant difference was found between patients with normal and elevated cerebrospinal fluid pressure. The ΔICPdifference was linearly correlated with the Lendifference and Voldifference. ΔICP was linearly correlated with Lendifference.
CONCLUSIONS: Complete obstruction of flow patency should be avoided in patients with low ICP and large volumetric/patency differences in the bilateral transverse-sigmoid sinus systems.

Few studies have discussed the disease nature and treatment outcomes for bilateral cavernous sinus dural arteriovenous fistula (CSDAVF). This study aimed to investigate the clinical features and treatment outcomes of bilateral CSDAVF. Embase, Medline, and Cochrane library were searched for studies that specified the outcomes of bilateral CSDAVF from inception to April 2022. The classification, clinical presentation, angiographic feature, surgical approach, and treatment outcomes were collected. Meta-analysis was performed using the random effects model. Eight studies reporting 97 patients were included. The clinical presentation was mainly orbital (n = 80), cavernous (n = 52) and cerebral (n = 5) symptoms. The most approached surgical route was inferior petrosal sinus (n = 80), followed by superior orbital vein (n = 10), and alternative approach (n = 7). Clinical symptoms of 88% of the patients (95% CI 80-93%, I2 = 0%) were cured, and 82% (95% CI 70-90%, I2 = 7%) had angiographic complete obliteration of fistulas during follow up. The overall complication rate was 18% (95% CI 11-27%, I2 = 0%). Therefore, endovascular treatment is an effective treatment for bilateral CSDAVF regarding clinical or angiographic outcomes. However, detailed evaluation of preoperative images and comprehensive surgical planning of the approach route are mandatory owing to complexity of the lesions.