Extent of transverse sinus stenosis does not predict visual outcomes in idiopathic intracranial hypertension.

BACKGROUND: We aimed to investigate whether the degree of transverse sinus stenosis (TSS) on magnetic resonance venography (MRV) can predict visual outcomes in patients with idiopathic intracranial hypertension (IIH). METHODS: A chart review identified IIH patients followed for at least 6 months. Mean deviation (MD) on visual field (VF) testing at initial and last follow-up visits, best corrected visual acuity (BCVA), patients' age, body mass index, and lumbar puncture opening pressure were recorded. MRV was used to grade TSS on a scale of 0-8 using the grading scheme proposed by Farb et al., whereby a lower score indicates a greater degree of stenosis. Linear regression analysis was used to test for association between above variables and MD on VF, including change in MD over time. RESULTS: 44 female patients were followed for a median of 26 months. All patients had unilateral or bilateral TSS on MRV. The median TSS score was 3/8. The median BCVA was 0.06 logMAR at baseline. The median VF MD was -3.02 dB at baseline and -1.96 dB at final follow-up. There was no significant association between the degree of TSS and either baseline MD (P-value = 0.34) or the change in MD on VF over the course of follow-up (P-value = 0.54). Baseline BCVA (P = 0.045) and baseline MD (P < 0.001) were the only significant predictors of changes in MD on VF over follow-up. CONCLUSIONS: Baseline BCVA and MD on VF were the only significant predictors of visual outcome in IIH patients. While all patients demonstrated TSS on MRV, the degree of TSS did not correlate with visual prognosis.

Torrents of torment: turbulence as a mechanism of pulsatile tinnitus secondary to venous stenosis revealed by high-fidelity computational fluid dynamics.

BACKGROUND: Pulsatile tinnitus (PT) is a debilitating condition that can be caused by a vascular abnormality, such as an arterial or venous lesion. Although treatment of PT-related venous lesions has been shown to successfully cure patients of the associated 'tormenting' rhythmical sound, much controversy still exists regarding their role in the etiology of PT. METHODS: A patient presented with a history of worsening, unilateral PT. A partial venous sinus obstruction related to the large arachnoid granulation was detected on the right side, and subsequently stented at the right transverse sinus. High-fidelity computational fluid dynamics (CFD) was performed on a 3D model digitally segmented from the pre-stent venogram, with assumed pulsatile flow rates. A post-stent CFD model was also constructed from this. Data-driven sonification was performed on the CFD velocity data, blinded to the patient's self-reported sounds. RESULTS: The patient reported that the PT was completely resolved after stenting, and has had no recurrence of the symptoms after more than 2 years. CFD simulation revealed highly disturbed, turbulent-like flow at the sigmoid sinus close to auditory structures, producing a sonified audio signal that reproduced the subjective sonance of the patient's PT. No turbulence or sounds were evident at the stenosis, or anywhere in the post-stent model. CONCLUSIONS: For the first time, turbulence generated distal to a venous stenosis is shown to be a cause of PT. High-fidelity CFD may be useful for identifying patients with such 'torrents' of flow, to help guide treatment decision-making.

Low incidence of true Sternberg's canal defects among lateral sphenoid sinus encephaloceles.

BACKGROUND: Spontaneous sphenoid sinus cerebrospinal fluid (CSF) encephaloceles have been postulated to arise from a persistent Sternberg's canal. However, recent evidence has questioned this embryological etiology. We examined the anatomic location of a series of lateral sphenoid sinus encephaloceles to determine if they corresponded with the location of Sternberg's canal. METHODS: We queried a prospectively acquired database of surgically treated spontaneous CSF leaks and identified those arising from the sphenoidal sinus. Images were reviewed to characterize the leaks with respect to the foramen rotundum (FR) and the vidian canal (VC). Four leak types were classified of which Type I (medial to FR and VC entering nasopharynx) was theoretically located in the precise location of Sternberg's canal. Type II was medial to FR; Type III was lateral to FR; Type IV passed through an enlarged FR into sphenoid sinus. Demographic data were analyzed. RESULTS: Of 103 repaired CSF leaks, 17 arose from the lateral sphenoid sinus. There were no true Type I leaks, 3 Type II leaks, 12 Type III leaks, and 2 Type IV leaks. No differences were found with respect to sphenoid pneumatization, BMI, age, sex, arachnoid pits, or postoperative leak between different types. CONCLUSIONS: No evidence was found to support the existence of a classic Sternberg canal CSF leak, supporting the hypothesis that most sphenoid spontaneous leaks likely occur secondary to chronically elevated ICP. Rare cases may be related to a weakness in the sphenoid wall in the region of Sternberg's canal.

Minimally Invasive Approaches to the Lateral Cavernous Sinus and Meckel's Cave: Comparison of Transorbital and Subtemporal Endoscopic Techniques.

BACKGROUND: Transorbital and subtemporal keyhole approaches have recently been proposed to approach lesions in the lateral wall of the cavernous sinus (CS) and Meckel's cave (MC). Our goal was to compare these approaches and suggest indications for each of them. METHODS: Five cadaver heads (10 sides, 40 procedures) were used. The lateral transorbital approaches were carried out without and with the removal of the lateral orbital rim, herein referred to as the lateral transorbital approach (LTOA) and the lateral orbital wall approach (LOWA). The subtemporal approaches were performed without and with the removal of the zygomatic arch, referred to as the subtemporal approach (STA) and the subtemporozygomatic approach (STZA). Five targets were chosen and 2 triangles were created representing the lateral wall of the CS and MC. Stereotactic measurements were quantified to calculate angles of attack, surgical freedom, and temporal lobe retraction for each approach. RESULTS: LTOA presented the smaller horizontal angles of attack. LOWA increased the angles to the same level of STA and STZA. STA and STZA presented larger vertical angles of attack. The surgical freedom presented gradual increase from LTOA to LOWA, STA, and STZA. STA and STZA needed greater temporal lobe retraction for most targets. CONCLUSIONS: LTOA is a good option to biopsy a lesion in the lateral wall of the CS and LOWA increased the surgical corridor to work with microsurgical techniques. STA and STZA could be better options when wide exposure is necessary, but temporal lobe retraction should be taken into consideration.

Endovascular Treatment of Cerebral Venous Sinus Stenosis Based on Hemodynamic Assessment Using Pressure Wire.

BACKGROUND: A pressure wire offers a dynamic tool to assist in the measurement of the pressure gradient and assessment of the functional significance of stenosis. The author presents a patient with idiopathic intracranial hypertension who was diagnosed with cerebral venous sinus stenosis (CVSS). Venography accompanied by pressure measurement was used to guide the stent placement for CVSS. CASE DESCRIPTION: A 27-year-old woman was referred to our hospital with a chief complaint of headache and neckache lasting for 7 weeks, with an 8-day history of binocular diplopia and blurred vision. Magnetic resonance venography and digital subtraction angiography showed a filling defect in the right transverse sinus. A pressure wire was used before endovascular treatment and showed that the pressure gradient was 10 mm Hg, which meets the surgical indication. After a stent was placed, no pressure gradient was recorded by the pressure wire. CONCLUSIONS: This is the first report about using a pressure wire for CVSS. The finding suggests that use of a pressure wire can be a new approach in the diagnosis and treatment of CVSS.

Venous Sinus Stenting for Transverse Sinus Stenosis Associated with Leptomeningeal Carcinomatosis in a Patient with Epidermal Growth Factor Receptor-Mutated Lung Cancer: A Case Report.

BACKGROUND Cerebral venous sinus obstruction associated with leptomeningeal carcinomatosis is an extremely rare complication of advanced non-small-cell lung cancer. There is little information available on the efficacy of therapeutic options because of its rarity and extremely poor prognosis. CASE REPORT A 57-year-old man presented with severe headache, vomiting, and visual loss for 1 month. Head magnetic resonance venography (MRV) showed occlusion of the left transverse sinus. Gd-enhanced MRI showed no abnormal enhancement. Lumbar puncture intracranial pressure was higher than 40 cmH2O. Positive cerebrospinal fluid tumor cytology confirmed the diagnosis of leptomeningeal carcinomatosis (LC). The headache was relieved by repeated lumbar punctures, and ventriculo-peritoneal shunt was performed. Cerebral angiography showed severe stenosis of the left transverse sinus without thrombosis, and significant delay of cerebral circulation. The transverse sinus stenosis was judged to be contributing to raised intracranial pressure, and the patient underwent left transverse sinus stent placement. After the procedure, his visual acuity improved, the visual field was enlarged, and his headache could be controlled by medication. Follow-up Gd-enhanced MRI showed dural enhancement and spinal dissemination. Because molecular biology of the surgical specimen showed epidermal growth factor receptor (EGFR)-activating mutations, he was treated with osimertinib for 2 months. He survived for 8 months following the diagnosis of LC and left transverse sinus stenosis. CONCLUSIONS Venous sinus stenting can offer an effective palliative interventional option for symptom relief of severe headache and visual symptoms, even in the end stage of malignancy.

Role of contrast-enhanced magnetic resonance high-resolution variable flip angle turbo-spin-echo (T1 SPACE) technique in diagnosis of transverse sinus stenosis.

PURPOSE: Transverse sinus stenosis (TSS) is the most sensitive imaging characteristic of idiopathic intracranial hypertension (IIH). This study aimed to assess the diagnostic performance of contrast-enhanced magnetic resonance high-resolution variable flip angle turbo-spin-echo (T1 SPACE) technique in TSS patients and evaluate the diagnostic accuracy of enhanced T1 SPACE, and phase-contrast magnetic resonance venography (PC MRV) with digital subtraction angiography (DSA) as standard imaging. METHOD: This prospective study enrolled 62 patients with suspected IIH and PC MRV-confirmed transverse sinus stenosis. All patients underwent lumbar puncture, PC MRV, enhanced T1 SPACE sequences and DSA examination. The accuracy, sensitivity, and specificity of enhanced T1 SPACE in detecting venous sinus stenosis were calculated and compared with those of PC MRV. Intermodality agreement (Kendall's rank correlation coefficients and weighted kappa statistic) was assessed. RESULTS: Sixty-two patients were enrolled from November 2016 to October 2018. For the measured stenosis, better correlation was observed in enhanced T1 SPACE and DSA (AUC = 0.953) than PC MRV (AUC = 0.871). Intermodality agreement of enhanced T1 SPACE (rk = 0.895 and weighted ĸ = 0.868) was better than PC MRV (rk = 0.753 and weighted ĸ = 0.653) compared with DSA. Thirty-seven intrasinus filling defects were detected by contrast-enhanced T1 SPACE, while only twenty of them were detected on source imaging of PC MRV. CONCLUSIONS: The contrast-enhanced T1 SPACE sequence was more sensitive and specific compared with PC MRV in assessing stenosis and detecting lesions in TSS patients. Accurate determination of the presence and extent of TSS using this technique might be useful in patient selection and guiding the treatment.

Empty Sella Is a Sign of Symptomatic Lateral Sinus Stenosis and Not Intracranial Hypertension.

BACKGROUND AND PURPOSE: Empty sella has been reported in patients with idiopathic intracranial hypertension and is thought to be a sign of elevation of intracranial pressure. However, it can also be found in patients with lateral sinus stenosis presenting with isolated pulsatile tinnitus without signs of intracranial hypertension. We hypothesized that the volume of the sella turcica would be similar in both groups of patients undergoing stent placement for lateral sinus stenosis. MATERIALS AND METHODS: Consecutive patients with idiopathic intracranial hypertension or isolated venous pulsatile tinnitus and undergoing lateral sinus stent placement from January 2012 to December 2017 were included. The primary outcome was the estimated volume of the sella turcica based on preoperative CTA measurements. The ratio of the pituitary gland height/sellar height was calculated on preoperative MR imaging. Sellar volumes were compared among the 3 groups: pulsatile tinnitus, idiopathic intracranial hypertension, and a control group, matched by age and sex. RESULTS: Eighty-eight patients underwent lateral sinus stent placement. The median age was 37 years, and 94% were women. No difference in age, sex, or body mass index was found among the groups. Patients undergoing venous stent placement had significantly higher sellar volumes than the control group (P < 0.001). There was no difference in the sellar volumes (P = .63) or gland/sellar height ratios (P = .25) between the pulsatile tinnitus and idiopathic intracranial hypertension groups. CONCLUSIONS: Empty sella is found in 2 differing groups of patients undergoing lateral sinus stent placement, suggesting that it is a radiologic sign of symptomatic hemodynamic lateral sinus stenosis rather than elevated intracranial pressure.

Magnetic Resonance Imaging Findings in Pediatric Pseudotumor Cerebri Syndrome.

BACKGROUND: Revised diagnostic criteria for pseudotumor cerebri syndrome require three of four neuroimaging findings in the absence of papilledema. We examined the sensitivity and specificity of three or more of four of these magnetic resonance imaging (MRI) findings for pseudotumor cerebri syndrome in children. METHODS: As part of clinical care, patients in whom there was suspicion for pseudotumor cerebri syndrome underwent neurological and fundoscopic examinations, lumbar puncture, MRI, or magnetic resonance venogram. For this retrospective study, we used this information to classify 119 subjects into definite (n = 66) or probable pseudotumor cerebri syndrome (n = 12), elevated opening pressure without papilledema (n = 23), or controls who had normal opening pressure without papilledema (n = 24). A neuroradiologist, unaware of the clinical findings or original MRI report, reviewed MRIs for pituitary gland flattening, flattening of the posterior sclera, optic nerve sheath distention, and transverse venous sinus stenosis. RESULTS: The presence of three or more MRI findings has a sensitivity of 62% (95% confidence interval: 47% to 75%) and a specificity of 95% (95% confidence interval: 77% to 100%), compared with controls. Two of three (transverse venous sinus stenosis, pituitary gland flattening, flattening of the posterior sclera) had a similar sensitivity and specificity. Transverse venous sinus stenosis alone had a slightly higher sensitivity (74%, 95% confidence interval: 60% to 85%) and specificity (100%, 95% confidence interval: 80% to 100%). CONCLUSIONS: In children, three of four of the proposed neuroimaging criteria and transverse venous sinus stenosis alone have a moderate sensitivity and robust specificity for pseudotumor cerebri syndrome. MRIs should be reviewed for these criteria, and their presence should raise suspicion for pseudotumor cerebri syndrome in children, particularly if the presence of papilledema is uncertain.

Multiple Extraaxial Cavernous Hemangiomas: Rare Entity.

BACKGROUND: Cavernous hemangiomas arising in the extraaxial space are rarely encountered, often mimicking other more common pathologies. Furthermore, multiple coexisting lesions and posterior fossa involvement are scarcely reported. Herein, we present the case of a patient with concurrent frontal bone and posterior fossa extraaxial cavernous hemangiomas. We also review the challenges associated with the diagnosis and management of these entities. CASE DESCRIPTION: An otherwise healthy 41-year-old gentleman presented with a 7-month history of a progressive right forehead mass. Imaging demonstrated a right frontal bone mass and an incidentally noted transverse sinus-based mass. The patient opted for surgical resection of both lesions. A right frontal craniotomy was performed to remove the bony lesion, followed by a suboccipital approach for the dural-based mass. There were no significant complications intraoperatively, and gross total resection was achieved for both lesions. Final pathology for each was consistent with cavernous hemangioma. CONCLUSIONS: Extraaxial cavernous hemangiomas are uncommon clinical entities that are challenging to distinguish from other diseases. If intraoperative complications can be avoided, treatment with surgical resection often offers excellent patient outcomes.

Reduced Jet Velocity in Venous Flow after CSF Drainage: Assessing Hemodynamic Causes of Pulsatile Tinnitus.

BACKGROUND AND PURPOSE: Idiopathic intracranial hypertension is commonly associated with transverse sinus stenosis, a venous cause of pulsatile tinnitus. In patients with idiopathic intracranial hypertension, CSF drainage via lumbar puncture decreases intracranial pressure, which relieves the stenosis, and may provide at least temporary cessation of pulsatile tinnitus. The objective of this study was to evaluate changes in venous blood flow caused by lowered intracranial pressure in patients with pulsatile tinnitus to help identify the cause of pulsatile tinnitus. MATERIALS AND METHODS: Ten patients with suspected transverse sinus stenosis as a venous etiology for pulsatile tinnitus symptoms underwent MR imaging before and after lumbar puncture in the same session. The protocol included flow assessment and rating of pulsatile tinnitus intensity before and after lumbar puncture and MR venography before lumbar puncture. Post-lumbar puncture MR venography was performed in 1 subject. RESULTS: There was a lumbar puncture-induced reduction in venous peak velocity that correlated with the opening pressure (r = -0.72, P = .019) without a concomitant reduction in flow rate. Patients with flow jets had their peak velocity reduced by 0.30 ± 0.18 m/s (P = .002), correlating with a reduction in CSF pressure (r = 0.82, P = .024) and the reduction in subjectively scored pulsatile tinnitus intensity (r = 0.78, P = .023). The post-lumbar puncture MR venography demonstrated alleviation of the stenosis. CONCLUSIONS: Our results show a lumbar puncture-induced reduction in venous peak velocity without a concomitant reduction in flow rate. We hypothesize that the reduction is caused by the expansion of the stenosis after lumbar puncture. Our results further show a correlation between the peak velocity and pulsatile tinnitus intensity, suggesting the flow jet to be instrumental in the development of sound.

Occipital petalia as a predictive imaging sign for transverse sinus dominance.

OBJECTIVES: Occipital petalia is an anatomic description where one of the occipital lobes protrudes towards the contralateral side. Transverse sinus (TS) asymmetry might cause diagnostic challenges with regards to thrombotic or compressive pathologies involving these sinuses. In this study, we investigated the association between occipital petalia and TS hypoplasia on MRI studies. METHODS: In 264 subjects with no neurological complaints, occipital bending was determined on T1-weighted images based on the angulation of interhemispheric fissure between occipital lobes with respect to an imaginary midline. TS asymmetry was evaluated visually. Information on handedness and ocular dominance was also gathered from all participants. RESULTS: Rightwards bending was observed in 72 subjects (27%), whereas leftwards bending was present in only 10 participants (4%). The presence or direction of bending was related neither to hand nor ocular dominance. In participants with rightwards bending, 72% had a larger TS on the right-side, while only a single subject had a left-sided predilection for venous drainage. In subjects with leftwards bending, 70% had a left-dominant TS drainage system and none had a larger TS on the right. Overall, the direction of bending was predictive of TS dominance on the ipsilateral side with a PPV of 72% (95%CI, 60-82%) for right and 70% (95%CI, 35-92%) for left. DISCUSSION: The direction of bending, a relatively straightforward radiologic diagnosis, is closely linked to the side of TS hypoplasia, and thereby might provide physicians with an additional diagnostic clue regarding the interpretation of imaging findings related to TSs and their pathologies.

A quantitative and semi-automatic measurement of transverse sinus stenosis improves idiopathic intracranial hypertension diagnostic accuracy.

We propose a new reliable transverse sinus stenosis (TSS) index based on magnetic resonance venography (MRV) for the diagnosis of idiopathic intracranial hypertension (IIH). Our quantitative semi-automatic measurement analysis based on segmentation and cross-sectional TS diameter from 48 IIH patients and controls matched for age and sex, had a good inter-observer agreement (κ=0.729) compared to a visual examination (κ=0.467). A cut-off point≥2 discriminate IIH patients from controls, with a sensitivity and specificity of 100%.

Idiopathic Intracranial Hypertension: Prognostic Factors and Multidisciplinary Management.

BACKGROUND: Idiopathic intracranial hypertension (IIH) mostly affects young obese women and can lead to permanent visual impairment. However, prognostic factors and therapeutic strategy remain unclear. METHODS: We retrospectively collected data from all patients diagnosed and managed for IIH in our university center from January 2001 to December 2016. RESULTS: Seventy-nine patients were diagnosed with IIH. Bilateral transverse sinus stenosis (TSS) was found in 74% of the population. Visual outcome at 6 months was poor for 46% of patients, including all patients presenting weight gain of at least 5% since diagnosis (p < 0.001), whereas mean body mass index at diagnosis was not different between patients with poor versus good outcome (32.9 ± 7.7 versus 34.6 ± 9.4 kg·m-2). Other significant factors of poor prognosis were bilateral TSS (OR = 5.2; 95 CI: 1.24-24.9; p = 0.024). Thirteen patients with poor outcome after 6-month assessment underwent unilateral TSS stenting leading to visual improvement in 11 cases. CONCLUSION: Weight gain, rather than initial weight, emerged as the leading factor of poor visual outcome in patients with IIH, followed by presence of bilateral TSS. Consequently, first-line treatment must include dietary measures to control weight. Unilateral stenting appears to be a safe second-line treatment option for patients with bilateral TSS.

Cerebral Vein Malformations Result from Loss of Twist1 Expression and BMP Signaling from Skull Progenitor Cells and Dura.

Dural cerebral veins (CV) are required for cerebrospinal fluid reabsorption and brain homeostasis, but mechanisms that regulate their growth and remodeling are unknown. We report molecular and cellular processes that regulate dural CV development in mammals and describe venous malformations in humans with craniosynostosis and TWIST1 mutations that are recapitulated in mouse models. Surprisingly, Twist1 is dispensable in endothelial cells but required for specification of osteoprogenitor cells that differentiate into preosteoblasts that produce bone morphogenetic proteins (BMPs). Inactivation of Bmp2 and Bmp4 in preosteoblasts and periosteal dura causes skull and CV malformations, similar to humans harboring TWIST1 mutations. Notably, arterial development appears normal, suggesting that morphogens from the skull and dura establish optimal venous networks independent from arterial influences. Collectively, our work establishes a paradigm whereby CV malformations result from primary or secondary loss of paracrine BMP signaling from preosteoblasts and dura, highlighting unique cellular interactions that influence tissue-specific angiogenesis in mammals.

[Multiple Tentorial Dural Arteriovenous Fistulas with Acquired Pial Arteriovenous Fistula Presented with Unilateral Eye Symptoms Successfully Treated by Transarterial Embolization and Direct Surgery:A Case Report].

A 58-year-old man presented with slowly progressive chemosis, exophthalmos, and blepharedema of the left eye. Digital subtraction angiography revealed multiple dural arteriovenous fistulas(dAVFs)involving the bilateral tentorium, superior sagittal sinus, and right frontal convexity. In addition, occlusion of the left cavernous sinus and left sigmoid sinus were observed, which could lead to venous hypertension and might be associated with the occurrence of multiple dAVFs. Along with the congestion of the left ophthalmic vein, increased intracranial pressure due to the left tentorial dAVF with cortical venous reflux could have caused the left eye symptoms; therefore, the tentorial lesion was treated first. Although the proximal occlusion of the vein of Labbe, drainer of the left tentorial dAVF, was achieved after embolization using n-butyl cyanoacrylate via the external carotid artery, an arteriovenous shunt between the middle cerebral artery and the distal site of the vein of Labbe was newly visualized after embolization. The newly visualized lesion was treated with further surgical intervention. A pial AVF arising from several peripheral branches of the left middle cerebral artery with drainage into the distal site of the vein of Labbe was confirmed during the surgery, and interruption of the vein of Labbe was performed. The left eye symptoms of the patient significantly improved after the surgery, and postoperative angiogram revealed no residual shunt. Thus, the patient was treated using a combined approach of endovascular and direct surgeries, after which he recovered uneventfully.

Transverse Sinus Stenosis Is the Most Sensitive MR Imaging Correlate of Idiopathic Intracranial Hypertension.

BACKGROUND AND PURPOSE: Patients with idiopathic intracranial hypertension have transverse sinus stenosis on gadolinium-bolused MRV, but other MR imaging signs are less consistently seen. Our aim was to demonstrate that transverse sinus stenosis could be identified on conventional MR imaging, and this identification would allow improved diagnostic sensitivity to this condition. MATERIALS AND METHODS: MR imaging and MRV images from 63 patients with idiopathic intracranial hypertension and 96 controls were reviewed by using 3 independent procedures. MRV images were graded for the presence and degree of stenosis of the transverse sinus. Postgadolinium coronal T1-weighted sequences were evaluated independent of MRV. The dimensions of the proximal and distal transverse sinus were measured from the MRV examinations, and the cross-sectional area of the transverse sinus was calculated. Correlation among the 3 modes of evaluation of the transverse sinus was conducted by using Wilcoxon/Kruskal-Wallis, Pearson, and Spearman ρ nonparametric statistical techniques. RESULTS: Transverse sinus stenosis was identified bilaterally on MRV in 94% of patients with idiopathic intracranial hypertension and in 3% of controls. On coronal T1 postgadolinium MR images, transverse sinus stenosis was identified in 83% of patients with idiopathic intracranial hypertension and 7% of controls. Previously described MR imaging signs of intracranial hypertension were identified in 8%-61% of patients with idiopathic intracranial hypertension. Correlation among the 3 modes of evaluation was highly significant (P < .0001). CONCLUSIONS: Even without the assistance of an MRV sequence, neuroradiologists can validly identify bilateral transverse sinus stenosis in patients with intracranial hypertension more reliably than other previously described MR imaging findings in this condition. We conclude that transverse sinus stenosis is the most useful and sensitive imaging indicator of this disease state.

Quantifying the Cerebral Hemodynamics of Dural Arteriovenous Fistula in Transverse Sigmoid Sinus Complicated by Sinus Stenosis: A Retrospective Cohort Study.

BACKGROUND AND PURPOSE: Sinus stenosis occasionally occurs in dural arteriovenous fistulas. Sinus stenosis impedes venous outflow and aggravates intracranial hypertension by reversing cortical venous drainage. This study aimed to analyze the likelihood of sinus stenosis and its impact on cerebral hemodynamics of various types of dural arteriovenous fistulas. MATERIALS AND METHODS: Forty-three cases of dural arteriovenous fistula in the transverse-sigmoid sinus were reviewed and divided into 3 groups: Cognard type I, type IIa, and types with cortical venous drainage. Sinus stenosis and the double peak sign (occurrence of 2 peaks in the time-density curve of the ipsilateral drainage of the internal jugular vein) in dural arteriovenous fistula were evaluated. "TTP" was defined as the time at which a selected angiographic point reached maximum concentration. TTP of the vein of Labbé, TTP of the ipsilateral normal transverse sinus, trans-fistula time, and trans-stenotic time were compared across the 3 groups. RESULTS: Thirty-six percent of type I, 100% of type IIa, and 84% of types with cortical venous drainage had sinus stenosis. All sinus stenosis cases demonstrated loss of the double peak sign that occurs in dural arteriovenous fistula. Trans-fistula time (2.09 seconds) and trans-stenotic time (0.67 seconds) in types with cortical venous drainage were the most prolonged, followed by those in type IIa and type I. TTP of the vein of Labbé was significantly shorter in types with cortical venous drainage. Six patients with types with cortical venous drainage underwent venoplasty and stent placement, and 4 were downgraded to type IIa. CONCLUSIONS: Sinus stenosis indicated dysfunction of venous drainage and is more often encountered in dural arteriovenous fistula with more aggressive types. Venoplasty ameliorates cortical venous drainage in dural arteriovenous fistulas and serves as a bridge treatment to stereotactic radiosurgery in most cases.

Diagnosis of Transverse Sinus Hypoplasia in Magnetic Resonance Venography: New Insights Based on Magnetic Resonance Imaging in Combined Dataset of Venous Outflow Impairment Case-Control Studies: Post Hoc Case-Control Study.

In previous studies of transverse sinus (TS) hypoplasia, discrepancies between TS diameter measured by magnetic resonance venography (MRV) and contrast T1-weighted magnetic resonance (contrast T1) were observed. To investigate these discrepancies, and considering that TS hypoplasia is associated with neurological disorders, we performed a post hoc analysis of prospectively collected data from 3 case-control studies on transient global amnesia (TGA), transient monocular blindness (TMB), and panic disorders while retaining the original inclusion and exclusion criteria. Magnetic resonance (MR) imaging of 131 subjects was reviewed to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction.MRV without contrast revealed that TS hypoplasia was observed in 69 subjects, whom we classified into 2 subgroups according to the concordance with contrast T1 observations: concordance indicated anatomically small TS (30 subjects), and discrepancy indicated that the MRV diagnosis is in fact flow-related and that TS is not anatomically small (39 subjects). The latter subgroup was associated with at least 1 site of venous compression/stenosis in the internal jugular vein (IJV) or the left brachiocephalic vein (BCV) (P < 0.001), which was significantly larger in patients than controls. Compensatory dilatation of contralateral TS diameter was only observed with MRV, not with contrast T1 imaging.The clinical implication of these results is that using MRV only, IJV/BCV compression/stenosis may be misdiagnosed as TS hypoplasia. And contralateral TS have no compensatory dilatation in its diameter in contrast T1 imaging, just compensatory increased flow volume.

Delayed relapse in pseudotumor cerebri due to new stenosis after transverse sinus stenting.

A patient presented with recurrent severe pseudotumor cerebri (PTC). Transverse sinus stenting is a very effective treatment option, however stenosis and intracranial hypertension can recur. In our patient, stenting initially resulted in resolution of papilloedema. However, after 5 years, a new stenosis developed which required further stenting. This case highlights the fact that, in patients with PTC who undergo transverse sinus stenting, a small proportion require repeat treatment due to formation of a new stenosis, usually adjacent to the existing stent. Patients with severe disease, such as ours, may be at higher risk of recurrence. Regardless of the severity, all patients who undergo stenting should have regular ocular follow-up.