Unilateral transverse sinus stenting of patients with idiopathic intracranial hypertension

Differentiation Between the Low and High Trans-Stenotic Pressure Gradient in Patients With Idiopathic Intracranial Hypertension Using 4D Flow MRI-Derived Hemodynamic Parameters

BACKGROUND

Trans-stenotic pressure gradient (TPG) measurement is essential for idiopathic intracranial hypertension (IIH) patients with transverse sinus (TS) stenosis. Four-D flow MRI may provide a noninvasive imaging method for differentiation of IIH patients with different TPG.

PURPOSE

To investigate the associations between 4D flow parameters and TPG, and to evaluate the diagnostic performance of 4D flow parameters in differentiating patients with high TPG (GroupHP) from low TPG (GroupLP).

STUDY TYPE

Prospective.

POPULATION

31 IIH patients with TS stenosis (age, 38 ± 12 years; 23 females) and 5 healthy volunteers (age, 25 ± 1 years; 2 females).

FIELD STRENGTH/SEQUENCE

3T, 3D phase contrast MR venography, and gradient recalled echo 4D flow sequences.

ASSESSMENT

Scan-rescan reproducibility of 4D flow parameters were performed. The correlation between TPG and flow parameters was analyzed. The netflow and velocity difference between inflow plane, outflow plane, and the stenosis plane were calculated and compared between GroupHP and GroupLP.

STATISTICAL TESTS

Pearson's correlation or Spearman's rank correlation coefficient, Independent samples t-test or Wilcoxon rank-sum test, Intra-class correlation coefficient (ICC), Bland-Altman analyses, Receiver operating characteristic curves. A P value <0.05 was considered significant.

RESULTS

Significant correlations were found between TPG and netflow parameters including Favg,out-s, Favg,in-s, Fmax,out-s, and Fmax,in-s (r = 0.525-0.565). Significant differences were found in Favg,out-s, Fmax,out-s, Favg,in-s, and Fmax,in-s between GroupHP and GroupLP. Using the cut-off value of 2.19 mL/sec, the Favg,out-s showed good estimate performance in distinguishing GroupHP from GroupLP (AUC = 0.856). The ICC (ranged 0.905-0.948) and Bland-Altman plots indicated good scan-rescan reproducibility.

DATA CONCLUSIONS

4D flow MRI derived flow parameters showed good correlations with TPG in IIH patients with TS stenosis. Netflow difference between outflow and stenosis location at TS shows the good performance in differentiating GroupHP and GroupLP cases.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Venous sinus stenting for idiopathic intracranial hypertension: An updated Meta-analysis

BACKGROUND

Idiopathic intracranial hypertension (IIH) is characterized by elevated intracranial pressure and primarily affects obese women of reproductive age. Venous sinus stenting (VSS) is a surgical procedure used to treat IIH, but its safety and efficacy are still controversial.

METHODS

A systematic review and meta-analysis were conducted following PRISMA guidelines. Multiple databases were searched for studies evaluating the safety and efficacy of VSS in IIH patients and meta-analysis was performed to pool the data.

RESULTS

A total of 36 studies involving 1066 patients who underwent VSS were included. After VSS, a significant reduction in trans-stenotic gradient pressure was observed. Patients also showed significantly lower cerebrospinal fluid (CSF) opening pressure. Clinical outcomes demonstrated improvement in tinnitus (95%), papilledema (89%), visual disturbances (88%), and headache (79%). However, 13.7% of patients experienced treatment failure or complications. The treatment failure rate was 8.35%, characterized by worsening symptoms and recurrence of IIH. The complications rate was 5.35%, including subdural hemorrhage, urinary tract infection, stent thrombus formation, and others.

CONCLUSION

VSS appears to be a safe and effective treatment option for IIH patients who are unresponsive to medical therapy or have significant visual symptoms. However, long-term outcomes and safety of the procedure require further investigation.

Future Directions and Innovations in Venous Sinus Stenting

This review explores the future role of venous sinus stenting (VSS) in the management of idiopathic intracranial hypertension and pulsatile tinnitus. Despite its favorable safety profile and clinical outcomes compared with traditional treatments, VSS is not yet the standard of care for these conditions, lacking high-level evidence data and guidelines for patient selection and indications. Current and recently completed clinical trials are expected to provide data to support the adoption of VSS as a primary treatment option. Additionally, VSS shows potential in treating other conditions, such as dural arteriovenous fistula and cerebral venous sinus thrombosis, and it is likely that the procedure will continue to see an expansion of its approved indications. The current lack of dedicated venous stenting technology is being addressed with promising advancements, which may improve procedural ease and patient outcomes. VSS also offers potential for expansion into modulation of brain electrophysiology via endovascular routes, offering exciting possibilities for neurodiagnostics and treatment of neurodegenerative disorders.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

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.

Prediction of Venous Trans-Stenotic Pressure Gradient Using Shape Features Derived From Magnetic Resonance Venography in Idiopathic Intracranial Hypertension Patients

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis.

MATERIALS AND METHODS

This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features.

RESULTS

Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration.

CONCLUSION

Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

Idiopathic Intracranial Venous Hypertension: Toward a Better Understanding of Venous Stenosis and the Role of Stenting in Idiopathic Intracranial Hypertension

BACKGROUND

Venous sinus stenosis, typically at the junction of the transverse and sigmoid sinus, is increasingly recognized as a contributor to the pathophysiology of idiopathic intracranial hypertension (IIH), whether it be the intrinsic type that does not reverse with normalization of intracranial pressure or the extrinsic type, which does. Efforts to treat the stenosis and reduce the associated transstenotic gradient through placement of a stent at the site of stenosis have been studied over the past 2 decades, primarily through retrospective studies, with variable emphasis on formal visual testing and direct assessment of poststent opening pressure. Most studies have presented evidence for utilization of stenting as an alternative to cerebrospinal fluid shunting or optic nerve sheath fenestration in patients with IIH who harbor the stenosis and are refractory to or intolerant of intracranial pressure-lowering medications, but an assessment of the current data is needed to better understand the role of stenting for this patient population.

EVIDENCE ACQUISITION

A search in PubMed was made for "IIH," "papilledema," and "venous stenting." Data pre and post stenting, including symptoms attributable to IIH, intracranial pressure, papilledema, retinal nerve fiber layer thickening on optical coherence tomography, and visual field assessment (mean deviation), were collected. Need for retreatment and complications were assessed among all studies. Studies using stenting for special circumstances, such as cerebrospinal leaks or for stenosis along anomalous vessels, were reviewed.

RESULTS

In total, 49 studies (45 retrospective and 4 prospective) and 18 case reports (with 3 or less patients) were found and included in the analysis, for a total of 1,626 patients. In 250 patients in whom poststent intracranial pressure was measured, the mean value was 19.7 cm H 2 O, reduced from a mean of 33 cm H 2 O. Transient visual obscurations resolved in 79.6% of 201 patients who complained of it, pulsatile tinnitus resolved in 84.7% of 515, diplopia resolved in 93% of 86 patients, and nonspecific visual symptoms such as "blurry vision" improved in 76.2% of 537 patients. Headaches resolved in 36% and improved in a further 40.7% of 1,105 patients in whom they were documented before stenting. Of 1,116 with papilledema, 40.8% demonstrated resolution and 38.2% improvement. The mean retinal nerve fiber layer thickness improved from 170.2 µm to 89.2 µm among 402 eyes in which optical coherence tomography was used to measure it. Among 135 eyes in which formal visual fields were performed pre and post stenting, the prestent average mean deviation of -7.35 dB improved to -4.72 dB after stenting. Complications associated with stenting included in-stent stenosis or thrombosis, subdural hematoma, intracerebral hematoma, cerebral edema, stent migration, and death. A recurrence of symptoms requiring a follow-up surgical intervention occurred in 9%.

CONCLUSIONS

A growing body of evidence supports the use of venous sinus stenting as a viable option for medically refractory IIH, especially when papilledema threatens visual function. Complication and failure rates seem to be similar to alternative surgical approaches, although serious neurological sequalae can rarely occur. Emerging studies evaluating stent type, including novel stents designed for use in the venous system, may help improve ease of the procedure and long-term success rates. Prospective head-to-head studies are needed to better understand the performance of stenting compared with other interventions.

Venous sinus stenting for idiopathic intracranial hypertension patients with functioning ventriculoperitoneal shunts: A case series

Idiopathic intracranial hypertension (IIH) is a disease defined by increased intracranial pressure and associated with a variety of symptoms ranging from headaches to tinnitus. Ventricular peritoneal shunting has been the mainstay treatment for patients with IIH. Although VPS's have shown efficacy in treating IIH, some patients complain of refractory symptoms even with functioning VPS's. Venus stenting has emerged as a new technique for treating these refractory symptoms. Despite the scarce literature pertaining its efficacy and safety profile, several small studies have shown promising results. In this case series, four patients with IIH complained of refractory symptoms despite functioning VPS's and were treated with venous stenting.

Characteristics and Outcomes of the Idiopathic Intracranial Hypertension Treatment in Intrinsic and Extrinsic Stenosis: A Single-Center Experience in China

INTRODUCTION

This study aimed to explore the precipitating factors and evaluate the impact of different stenosis types on treatment outcomes in patients with idiopathic intracranial hypertension (IIH) and venous sinus stenosis (VSS).

METHODS

We recruited patients with IIH who presented with VSS, either intrinsic or extrinsic. We observed the clinical and laboratory findings, and we then compared the outcomes of stenting and medical treatment in different stenosis types.

RESULTS

Among 145 patients with IIH and VSS, 59 were of the intrinsic type and 86 were of the extrinsic type. Patients in the intrinsic group were older (42 vs. 34 years old, P < 0.001) and presented with higher pre-op gradient pressure (15 mmHg vs. 12 mmHg, P < 0.001). There was no significant difference between groups regarding other precipitating factors (P > 0.05). Stenting was significantly associated with complete resolution of the headache and impaired vision both in intrinsic (adjusted OR 0.017, 95% CI 0.001-0.35, P = 0.011; adjusted OR 0.056, 95% CI 0.004-0.697, P = 0.025, respectively) and extrinsic types of stenosis (adjusted OR 0.072, 95% CI 0.015-0.343, P = 0.001; adjusted OR 0.241, 95% CI 0.062-0.931, P = 0.039, respectively). Meanwhile, stenting was significantly associated with improvement of the papilledema in extrinsic-type stenosis compared with medical treatment (adjusted OR 0.017, 95% CI 0.002-0.135, P < 0.001).

CONCLUSION

Stenting may provide substantial clinical improvement in patients with IIH regardless of intrinsic or extrinsic stenosis type in our patient population, as noted in other series.

TRIAL REGISTRATION

Clinical trial registration number ChiCTR-ONN-17010421.

Idiopathic intracranial hypertension: Do we diagnose and manage it appropriately in the light of current data?

BACKGROUND AND OBJECTIVE

Idiopathic intracranial hypertension (IIH) is an increase of intracranial pressure without a known cause, which usually presented with headache. This study aimed to evaluate the changing diagnosis and management approaches of neurologists for IIH in light of recent data.

METHODS

An online questionnaire about IIH was developed covering 28 questions, and five sections: demographic data, diagnosis, examination, treatment, and follow-up. We compared the approach of neurologists with 1-9 years of experience (group-A) with that of neurologists with more than 10 years' experience (group-B).

RESULTS

A total of 517 neurologists (group A: n = 252, group B: n = 265) participated in the study. Responder rate of questionarre is 18.3%. The approach to IIH in diagnosis, examination, treatment, and follow-up processes was similar in both groups. The younger group (group A) recognized all neuro-radiologic findings, especially flattening of the posterior aspect of the globe (p = 0.001) and tortuosity of the optic nerve (p < 0.001) at higher rates compared with group B. The most commonly used medical treatment was acetazolamide (99%); corticosteroids were used more frequently by group B (p < 0.001). Optic nerve sheath fenestration (88.3%) was the first-line and ventriculo-peritoneal shunt (70.5%) was the second preferred surgical approach. It was observed that serial lumbar puncture applications (57.0%) were preferred more frequently than venous sinus stenting (19.0%) and bariatric surgery (10.0%).

CONCLUSIONS

The changing information in the last decade about IIH was more closely followed by younger neurologists despite their lesser experience, but classic methods were preferred in surgical approaches in both groups. Our findings indicated that post-graduate education and guidelines should be disseminated for IIH.

Apparent diffusion coefficient echoplanar imaging maps of the optic nerves in childhood idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

Dueto motion artifacts, optic nerve (ON) findings of idiopathic intracranial hypertension (IIH) can easily be overlooked on T2-weighted (T2w) turbo spin-echo sequence. This study aimed to investigate the contribution of the apparent diffusion coefficient (ADC) map derived from the interleaved multi-shot (IMS) echoplanar imaging (EPI) to the ON findings of IIH in children.

METHODS

MRIs of 42 pediatric patients aged 3-17 years diagnosed with definite IIH according to modified Dandy criteria were retrospectively re-evaluated, between April 2018 and January 2021. Forty-two age- and sex-matched subjects with no IIH symptoms and reported as normal were included as a control group.

RESULTS

ON sheath distance (ONSD) on the ADC map (p = .005) and vertical tortuosity (p = .030) were significant single MRI parameters for predicting IIH. Other single parameters were not statistically significant. Flattening of the posterior sclera (FPS) and ON protrusion (ONP) were observed on ADC maps more frequently than T2w (42.8% vs. 19% and 19% vs. 4.7%, respectively). From combined MRI parameters, the presence of at least one of ONP, FPS, or ONSD on ADC maps (p = .001) showed greater significance than the presence of T2w (p = .048). The predictive values of other MRI findings evaluated together were not statistically significant (p > .05).

CONCLUSIONS

This study's results show that due to the short readout time and less sensitivity to motion, the ADC map obtained from IMS-EPI can contribute to orbital findings of IIH, in addition to T2w.

Navigability of a long sheath in the lateral dural sinuses facilitated by the pilot balloon technique: technical note

Dural sinus stenting is an increasingly recognized intervention for the treatment of lateral sinus stenosis. This procedure can be challenging in tortuous anatomy and in the presence of intraluminal septa because of poor trackability and crossability of long sheath commonly used for stenting. We report a technique using a pilot angioplasty balloon positioned at the distal end of the long sheath that improves its navigability in dural sinuses and facilitated the intervention.

Case series of idiopathic intracranial hypertension in three patients with immune-complex glomerulonephritis

BACKGROUND

Idiopathic intracranial hypertension (IIH) is defined by an increased cerebrospinal fluid pressure in the absence of inflammation, structural obstructions, or mass lesions. Although the underlying pathogenesis of IIH is not fully understood, associations with specific risk factors as obesity, obstruction of cerebral venous sinuses, medications, endocrine or systemic conditions and chronic kidney disease have been described. Immune-complex glomerulonephritis as IgA-nephropathy is a frequent cause of chronic kidney failure, which was reported previously in one IIH patient. To date, there is no knowledge about the variable relation of immune-complex nephritis, kidney function and the course of IIH.

CASE PRESENTATION

We report three cases (two females) of concurrent diagnosis of IIH and immune-complex glomerulonephritis. All patients presented with typical IIH symptoms of headache and visual disturbances. Two patients had been diagnosed with IgA-nephropathy only few weeks prior to IIH diagnosis. The third patient had been diagnosed earlier with terminal kidney failure due to a cryoglobulin glomerulonephritis.

CONCLUSION

We propose a possible link between renal deposition of immune-complexes and increased cerebrospinal fluid pressure. Pathophysiological hypotheses and clinical implications are discussed. We recommend clinical awareness and further systematic research to obtain more information on the association of IIH and immune-complex glomerulonephritis.

C1 Transverse Process Resection for Management of Jugular Stenosis

BACKGROUND AND IMPORTANCE

Idiopathic intracranial hypertension, also known as pseudotumor cerebri, often presents with severe headache and associated vision loss. Venous outflow obstruction has been noted as a prominent etiologic factor in many cases, and previous anatomic studies have shown that the internal jugular (IJ) vein at the skull base can be prone to compression by the neighboring bony structures.

CLINICAL PRESENTATION

We present a case of 13-yr-old male with a multifactorial intracranial hypertension including compression of the IJ vein by the transverse process of C1. Computerized tomography angiographic imaging revealed bilateral stenosis of the IJ veins due to compression from the transverse processes of C1. Medical management and shunt were attempted without resolution of symptoms. A hemodynamically significant stenosis at the right IJ was confirmed with manometry and so the C1 transverse process was resected and a stent placed endovascularly with resolution of pressure gradient and clinical symptoms.

CONCLUSION

Contribution of C1 compression to this patient's intracranial hypertension suggests that evaluation for IJ compression below the skull base may be needed to identify the underlying cause of intracranial hypertension in certain patients. Furthermore, surgical decompression of the IJ vein may be required as part of the treatment strategy. If venous stenting is being considered, this decompressive step must be taken before stenting is performed. We offer this case as evidence that decompression of the IJ vein by C1 lateral mass resection can be an effective and novel technique in the repertoire of neurosurgical management of intracranial hypertension.

Dural venous sinus stenting in the treatment of idiopathic intracranial hypertension: A systematic review and critique of literature

Idiopathic intracranial hypertension (IIH) is increased intracranial pressure without a known cause. Dural venous sinus stenting (DVSS) is a relatively new intervention for treatment of IIH refractory to medical therapy and lifestyle modifications. In this review, we outline various hypotheses of IIH pathogenesis and describe the role of venous sinus stenosis and the technical details of DVSS. We also present a summary and critique of the available evidence describing the outcomes of DVSS in IIH and review the evidence-based guidelines for this procedure. We conclude that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and postprocedure ophthalmological data. Thus, there is not enough available evidence to conclude whether DVSS is an effective procedure for treatment of IIH. We also present the most commonly used indications for DVSS as described in the literature and stress the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.

Major complications of dural venous sinus stenting for idiopathic intracranial hypertension: case series and management considerations

BACKGROUND

Venous sinus stenting (VSS) is a safe, effective, and increasingly popular treatment option for selected patients with idiopathic intracranial hypertension (IIH). Serious complications associated with VSS are rarely reported.

METHODS

Serious complications after VSS were identified retrospectively from multicenter databases. The cases are presented and management strategies are discussed.

RESULTS

Six major acute and chronic complications after VSS were selected from a total of 811 VSS procedures and 1466 venograms for IIH. These included an acute subdural hematoma from venous extravasation, cases of both intraprocedural and delayed stent thrombosis, an ultimately fatal cerebellar hemorrhage resulting in acute obstructive hydrocephalus, venous microcatheter perforation during venography and manometry, and a patient who developed subarachnoid hemorrhage and subdural hematoma after cerebellar cortical vein perforation. The six cases are reviewed and learning points regarding complication avoidance and management are presented.

CONCLUSION

We report on six rare, major complications after VSS for IIH. Familiarity with these potential complications and appropriate timely management may allow for good clinical outcomes.

Venous sinus stenting for intractable pulsatile tinnitus: A review of indications and outcomes

Background:

Pulsatile tinnitus presents as a unique variation of tinnitus in which a conscious perception of the heartbeat is localized to the ears in either unilateral or bilateral fashion. The sensation is typically caused by an increase in turbulent blood flow in the affected ear, in most cases, due to a structural abnormality of the venous sinuses – the most common of which being stenosis. Herein, we discuss the etiology of pulsatile tinnitus followed by indications for treatment of various pathologies which have been successfully treated with venous sinus stenting and have led to resolution of auditory symptoms.

Methods:

The authors queried PubMed database using combinations of the keywords “venous sinus stenting,” “endovascular treatment,” and “pulsatile tinnitus” to identify relevant studies published in English after 2001 and before December 1, 2020 and verified selected.

Results:

Our results corroborate those published in prior reviews reporting a high rate of pulsatile tinnitus resolution with venous sinus stenting.

Conclusion:

The success of venous sinus stenting is clinically relevant as an effective treatment option for patients suffering from pulsatile tinnitus. Future applications and studies are needed and are currently being developed to further demonstrate the effectiveness of stents in the treatment of pulsatile tinnitus.

Space Flight-Associated Neuroocular Syndrome, Idiopathic Intracranial Hypertension, and Pseudotumor Cerebri: Phenotypic Descriptions, Pathogenesis, and Hydrodynamics

Recent data from astronauts who have returned to Earth from a long-duration space flight have unequivocally distinguished spaceflight-associated neuro-ocular syndrome (SANS) from idiopathic intracranial hypertension (IIH) and pseudotumor cerebri (PTC). We review the semiology and pathogenesis of these three entities, noting that optic disc edema is what unites them, and this where the similarities between SANS and IIH/PTC end. We distinguish between PTC and IIH and between SANS and IIH/PTC and review the medical and surgical therapy of IIH/PTC. The key to understanding the phenomenon of optic disc edema is the geometry of the optic nerve sheath, which is a simulacrum of an inverted Venturi tube. This allows us to theoretically study the hydrodynamics of the optic nerve sheath by applying simple physical laws, including the Venturi effect, Poiseuille’s law, and Reynold’s number, and we speculate on nature’s design and the correlation of form and function in understanding how cerebrospinal fluid (CSF) circulates in the optic nerve sheath as it approaches the optic nerve head. Recent spectacular data on the histology of the blood nerve-barrier of the optic nerve disc and the glymphatic system of the optic nerve sheath will also help us understand the development of optic disc edema due to the microgravity-induced cephalad shift of CSF in SANS. We will explore the role of the sodium/potassium adenosine triphosphatase (ATPase) pump on choroid plexus epithelial cells and the aquaporin-4 water receptors located on astrocyte end-feet and their complex interactions with the tetracyclines, mineralocorticoids, and therapeutic agents with carbonic anhydrase activity. We also adumbrate the complex interactions between obesity, vitamin A, and 11-beta-hydroxysteroid dehydrogenase and how the aquaporin-4 receptor relates to these interactions.

Relentless pulsatile tinnitus secondary to dural sinovenous stenosis: is endovascular sinus stenting the answer?

AIM

To assess the efficacy of endovascular venous sinus stenting (EVSS) in treating pulsatile tinnitus (PT) caused by dural venous sinus stenosis (DVSS), and to determine whether it is an adequate remedy in cases with concurrent venous anomalies.

MATERIALS AND METHODS

Seventeen patients (13 female and four male) with PT due to DVSS were treated using EVSS. The trans-stenotic pressure gradient (PG) was measured before and after stenting. The effect of stenting on the tinnitus was evaluated by questioning the patients at day 0, and at 3, 6, and 9 months after stenting.

RESULTS

Except for one patient who continued to complain of PT, all of the patients, including two with concomitant sinus diverticula, described complete resolution of the tinnitus immediately following stenting. The post-stenting PG was significantly lower than the pre-stenting PG (p<0.0001). No procedure related complications occurred and no recurrence was recorded during the follow-up period.

CONCLUSION

EVSS is a safe and successful treatment for PT due to DVSS even in cases with coexistent sinus diverticula.

A Case of Idiopathic Intracranial Hypertension Treated by Transverse Sinus Stenting

Objective

We report a patient with chronic headache due to idiopathic intracranial hypertension (IIH) associated with transverse sinus (TS) stenosis. The symptom improved after stent placement at the site of stenosis.

Case Presentation

The patient was a 37-year-old woman with progressive headache and diplopia as chief complaints. She had severe bilateral papilledema. Magnetic resonance imaging (MRI) and angiography revealed stenosis of the bilateral TS. Lumbar puncture demonstrated raised intracranial pressure and IIH was tentatively diagnosed. Visual impairment progressed despite oral acetazolamide therapy. A venous pressure gradient was monitored during stent placement. The pressure gradient improved after stenting. Dual antiplatelet therapy was initiated 1 week before the procedure. Papilledema and headache resolved immediately after the procedure. No in-stent stenosis or occlusion occurred during the follow-up period.

Conclusion

Stent placement for TS stenosis can improve the cerebral venous return in IIH patients. Although restenosis is possible, venous sinus stenting is considered an effective treatment.

Utility of Magnetic Resonance Imaging Features for Improving the Diagnosis of Idiopathic Intracranial Hypertension Without Papilledema

OBJECTIVE

Revised diagnostic criteria for idiopathic intracranial hypertension (IIH) were proposed in part to reduce misdiagnosis of intracranial hypertension without papilledema (WOP) by using 3 or 4 MRI features of intracranial hypertension when a sixth nerve palsy is absent. This study was undertaken to evaluate the sensitivity and specificity of the MRI criteria and to validate their utility for diagnosing IIH in patients with chronic headaches and elevated opening pressure (CH + EOP), but WOP.

METHODS

Brain MRIs from 80 patients with IIH with papilledema (WP), 33 patients with CH + EOP, and 70 control patients with infrequent episodic migraine were assessed in a masked fashion for MRI features of intracranial hypertension.

RESULTS

Reduced pituitary gland height was moderately sensitive for IIH WP (80%) but had low specificity (64%). Increased optic nerve sheath diameter was less sensitive (51%) and only moderately specific (83%). Flattening of the posterior globe was highly specific (97%) but had low sensitivity (57%). Transverse venous sinus stenosis was moderately sensitive for IIH WP (78%) but of undetermined specificity. A combination of any 3 of 4 MRI features was nearly 100% specific, while maintaining a sensitivity of 64%. Of patients with CH + EOP, 30% had 3 or more MRI features, suggesting IIH WOP in those patients.

CONCLUSION

A combination of any 3 of 4 MRI features is highly specific for intracranial hypertension and suggests IIH WOP when present in patients with chronic headache and no papilledema.

Idiopathic Intracranial Hypertension: Contemporary Management and Endovascular Techniques

Idiopathic intracranial hypertension (IIH) is a disease process of abnormally increased intracranial pressure in the absence of a mass lesion. Medical management, optic nerve fenestration, and surgical shunting procedures have failed to produce consistently successful results. In an unknown percentage of cases, IIH is caused by dural venous sinus obstruction which can be cured by endovascular treatment with dural venous sinus stent placement. This helps prevent progressive vision loss and worsening papilledema caused by underlying increased intracranial pressure from venous outflow obstruction. Patients are required to have an established diagnosis of IIH, preferably made by a neuroophthalmologist, with clearly documented papilledema or at minimum visual disturbance along with lumbar puncture opening pressure greater than 25 cm H ₂ O. Transverse to sigmoid sinus focal narrowing (intraluminal filling defect or extrinsic compression) must be seen during the venous phase of neuroangiography (NA) along with a pressure gradient of 10 mm Hg or greater across the focal narrowing during dural venous sinus pressure monitoring. A successful reduction is defined as a pressure gradient of less than 10 mm Hg after stent placement. Neuroophthalmologic follow-up occurs within 1 to 2 months to assess for changes in papilledema. If papilledema is unchanged or worsened, NA and hemodynamic evaluation is repeated for consideration of restenting. Appropriate patient selection criteria are required for IIH venous sinus stenting. The utilization of refined endovascular techniques along with postprocedure follow-up protocols can ultimately cure IIH for a select group of patients.

A systematic review of surgical treatments of idiopathic intracranial hypertension (IIH)

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

Migraine or idiopathic intracranial hypertension: Magnetic resonance venography and magnetic resonance imaging findings

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a disease characterised by increased cerebral pressure without a mass or hydrocephalus. We aimed to differentiate migraine and IIH patients based on imaging findings.

RESULTS

Patients with IIH (n = 32), migraine patients (n = 34) and control subjects (n = 33) were evaluated. Routine magnetic resonance imaging, contrast-enhanced 3D magnetic resonance venography and/or T1-weighted 3D gradient-recalled echo were taken with a 1.5 T magnetic resonance scanner. Optic-nerve sheath distention, flattened posterior globe and the height of the pituitary gland were evaluated in the three groups. Transverse sinuses (TS) were evaluated with respect to score of attenuation/stenosis and distribution. Pearson chi-square, Fisher's exact test and chi-square trend statistical analyses were used for comparisons between the groups. A p-value of <0.05 was considered statistically significant. Decreased pituitary gland height, optic-nerve sheath distention and flattened posterior globe were found to be statistically significant (p < 0.001) in IIH patients. Bilateral TS stenosis was also more common in IIH patients than in the control group and migraine group (p = 0.02).

CONCLUSION

Decreased pituitary gland height, optic-nerve sheath distention, flattened posterior globe, bilateral stenosis and discontinuity in TS are significant findings in differentiating IIH cases from healthy individuals and migraine patients. Bilateral TS stenosis may be the cause rather than the result of increased intracranial pressure. The increase in intracranial pressure, which is considered to be responsible for the pathophysiology of IIH, is not involved in the pathophysiology of migraine.

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.

Exploring The Current Management Idiopathic Intracranial Hypertension, And Understanding The Role Of Dural Venous Sinus Stenting

Idiopathic Intracranial Hypertension (IIH) is a debilitating disorder characterised by raised intracranial pressure (ICP), papilloedema with the potential risk of permanent visual loss, and headaches that are profoundly disabling and reduce the quality of life. The first consensus guidelines have been published on investigation and management of adult IIH and one key area of uncertainty is the utility of dural venous sinus stenting for the management of headache and visual loss. There are an increasing number of series published and to help understand the successes and complications. During a patient physician priority setting, the understanding of the best type of intervention to treat IIH was assigned to the top 10 of most desired research questions for the disease. Ultimately randomised clinical trials (RCTs) in neurovascular stenting for IIH would be instructive, as the literature to date may suffer from publication bias. Due to the increasing incidence of IIH, there is no better time to systematically investigate interventions that may reverse the disease process and achieve remission. In this review we discuss the pathophysiology of IIH in relation to venous sinus stenosis, the role of venous sinus stenting with a review of the relevant literature, the advantages and disadvantages of stenting compared with other surgical interventions, and the future of stenting in the treatment of IIH.

Understanding the complex pathophysiology of idiopathic intracranial hypertension and the evolving role of venous sinus stenting: a comprehensive review of the literature

Idiopathic intracranial hypertension (IIH) is a disease defined by elevated intracranial pressure without established etiology. Although there is now consensus on the definition of the disorder, its complex pathophysiology remains elusive. The most common clinical symptoms of IIH include headache and visual complaints. Many current theories regarding the etiology of IIH focus on increased secretion or decreased absorption of cerebrospinal fluid (CSF) and on cerebral venous outflow obstruction due to venous sinus stenosis. In addition, it has been postulated that obesity plays a role, given its prevalence in this population of patients. Several treatments, including optic nerve sheath fenestration, CSF diversion with ventriculoperitoneal or lumboperitoneal shunts, and more recently venous sinus stenting, have been described for medically refractory IIH. Despite the availability of these treatments, no guidelines or standard management algorithms exist for the treatment of this disorder. In this paper, the authors provide a review of the literature on IIH, its clinical presentation, pathophysiology, and evidence supporting treatment strategies, with a specific focus on the role of venous sinus stenting.

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.

Neuroendovascular Cerebral Sinus Stenting in Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a rare, ill-understood disease of significant morbidity. Because the pathophysiology is poorly understood, treatment protocols are not uniform and are directed towards alleviating the most common symptoms: headache and visual loss. In this review, we analyze 25 case series, all of which included IIH patients (n = 408) who were treated with placement of a venous sinus stent. Among 342 patients who had headache, 240 patients (70.2%) had improvement or resolution of headache after the stent insertion. Of the 217 patients documented to have visual problems, visual acuity was improved or stabilized in 161 patients (74.2%). Of the 304 patients with papilledema, 257 showed resolution or improved (84.5%). Of the 124 patients who presented with pulsatile tinnitus, it was resolved in 110 patients (88.7%) after stent placement. Endovascular management of dural sinus stenosis is therefore clinically efficacious in patients with IIH who have failed medical and surgical therapy.

Endovascular treatment of idiopathic intracranial hypertension caused by multiple venous sinus stenoses

Background:

Idiopathic intracranial hypertension (IIH) shows symptoms by elevating intracranial pressure. Although sinus stenosis has been detected in many patients with IIH, the role of sinus stenosis in IIH remains obscure. Endovascular treatment for IIH due to transverse sinus stenosis has been frequently documented; however, IIH due to multiple sinus stenoses including the superior sagittal sinus (SSS) is rare. Here, we report a case of IIH due to multiple sinus stenoses treated by sinus stenting.

Case Presentation:

A 47-year-old woman suffered from intractable headache with IIH presented with stenosis of the right transverse and SSS. Stent placement was carried out since intracranial hypertension and trans-stenotic cerebral venous pressure gradient (CVPG) were presented, and her intractable headache disappeared.

Conclusion:

IIH can be caused by venous sinus stenoses and stent placement could be an appropriate treatment in patients who demonstrated a CVPG.

Femoral-Long Sheath-Reshape-Anchoring-Stenting (FLRAS) Technique in Venous Sinus Stenting for Idiopathic Intracranial Hypertension

OBJECTIVE

To evaluate the efficacy and safety of the novel Femoral-Long Sheath-Reshape-Anchoring-Stenting (FLRAS) technique (developed by Dr. Hongbo Zheng) for venous sinus stenting in patients with idiopathic intracranial hypertension.

DESIGN

Retrospective, single center study.

MATERIALS AND METHODS

We comparatively analyzed clinical and imaging data from consecutive patients with idiopathic intracranial hypertension who underwent venous sinus stenting using either traditional technique from June 2013 to May 2015 or FLRAS technique (described in this mansucript) from May 2015 to May 2018.

RESULTS

A total of 20 patients (mean age, 36.7 [range, 17-50] years; 15 women) were enrolled in the study. In FLRAS group (n=12) vs. traditional stenting group (n=8): mean procedure duration was significantly shorter (48.3 min vs. 92.5 min, P <0.001), and procedure success rate was numerically higher (100% vs. 87.5%, P>0.05), with no vs. 2 complications, respectively.

CONCLUSIONS

Use of FLRAS technique for venous sinus stenting in patients with idiopathic intracranial hypertension appeared to yield favorable outcomes relative to use of the traditional stenting technique. A large, multicenter, randomized study is warranted to confirm these findings.

Endovascular Treatment of Idiopathic Intracranial Hypertension with Stenting of the Transverse Sinus Stenosis

For many years, the pathophysiology of idiopathic intracranial hypertension (IIH) was interpreted as “secondary intracranial hypertension,” and IIH was considered to be caused by brain edema due to obstructive sleep apnea. Another theory proposed cerebrospinal fluid (CSF) absorption impairment due to excessive medication with vitamin A derivatives. Other reports pointed out the importance of obesity, which may cause an impairment of intracranial venous drainage due to elevated right atrial pressure. Patients with medically refractory IIH have traditionally undergone a CSF diversion. Venous outlet impairment on IIH has recently been reported as a causative or contributory cause, and thus focused venoplasty of the stenotic sinus with a stent has emerged as a new treatment strategy. We report the cases of two patients who presented with headache and papilledema with IIH. They successfully underwent stent placement at the stenosis of the transverse sinus and experienced complete resolution of symptoms.

Endovascular Treatment for Venous Sinus Stenosis in Idiopathic Intracranial Hypertension: An Observational Study of Clinical Indications, Surgical Technique, and Long-Term Outcomes

BACKGROUND

Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure. IIH causes significant morbidity marked by incapacitating headaches and visual disturbances. This study investigated the long-term outcomes of venous sinus stenting in a large group of patients with IIH.

METHODS

We retrospectively reviewed all patients at our institution who underwent venous sinus stenting for IIH over 6 years (July 1, 2012-June 30, 2018). A particular focus was dedicated to collecting demographic, clinical, radiologic, and outcomes data. All patients had failed medical management.

RESULTS

Of the 110 patients evaluated for IIH, 42 underwent venous sinus stenting, with a mean follow-up of 25.6 months (range, 8.7-60.7 months). The mean age was 32 years (range, 15-52 years), 38 (90%) were women, and the mean body mass index was 35.6 kg/m² (range, 18.6-47.5 kg/m²). Prior to the stenting procedure, all patients had headaches, visual disturbances, and papilledema. Of the 39 patients who had an ophthalmologic evaluation poststenting, 29 (74%) had resolution of their papilledema. Eighteen patients (43%) had complete resolution of their headaches after the stenting procedure, whereas 22 patients (52%) remained under a neurologist's care for chronic migraine and other types of headaches. Two patients underwent a restenting procedure for disease progression, and 1 patient experienced an in-stent thrombosis.

CONCLUSIONS

A multidisciplinary approach involving neurosurgeons, ophthalmologists, radiologists, and neurologists is integral in the management of patients with IIH to prevent the complications of papilledema. Venous sinus stenting offers a safe and effective means of treating IIH.

Dural venous sinus stenting for idiopathic intracranial hypertension: An updated review

BACKGROUND

Dural venous sinus stenting (DVSS) is an accepted treatment option in selected patients with medically refractory idiopathic intracranial hypertension and obstructive venous outflow physiology prior to cerebrospinal flow diversion (CSFD) surgery. There are no randomized controlled studies focusing on outcomes and complication rates for dural venous sinus stenting.

PURPOSE

We present the largest comprehensive meta-analysis on DVSS for idiopathic intracranial hypertension (IIH) focusing on success rates, complications, and re-stenting rates to date. We also present a simplified approach to direct retrograde internal jugular vein (IJ) access for DVSS that allows for expedited procedures.

MATERIALS AND METHODS

We performed a retrospective electronic PubMed query of all peer-reviewed articles in the last 15 years between 2003 to 2018. We included all patients who underwent dural venous sinus stenting for a medically refractive IIH and excluded articles without sufficient data on outcomes, complication rates and re-stenting rates. We also evaluated and compared outcomes in patients undergoing direct retrograde IJ access DVSS to traditional transfemoral vein access.

RESULTS

A total of 29 papers and 410 patients who underwent DVSS met criteria for inclusion. DVSS was associated with high technical success [99.5%], low rates of repeated procedure [10%], and low major complication rates [1.5%].

CONCLUSION

Our retrospective comprehensive review of DVSS for medically refractory IIH suggests that stenting in appropriately chosen patients is associated with low complication rates, high technical success, and low repeat procedure rates.

Venous sinus stenting for idiopathic intracranial hypertension: a systematic review and meta-analysis

Background

Stenting of the intracranial venous sinuses is used as a treatment in certain cases of idiopathic intracranial hypertension (IIH). Interest in, and experience of, this technique is growing, particularly in recent years. We sought to provide an updated systematic review and meta-analysis of the use of venous stenting in these patients, examining clinical outcomes.

Methods

A literature search of venous stenting in IIH patients was performed. Using random-effects meta-analysis, we evaluated the following outcomes: clinical resolution of papilledema; headaches and pulsatile tinnitus; recurrence of symptoms after stenting; and complications.

Results

Twenty articles from 18 different centers were included. In a total of 474 patients. 418 were female (88%). The mean age of the patients was 35, while the mean body mass index (BMI) was 35 kg/m2. Median follow-up was 18 months. The overall rate of improvement in papilloedema was 93.7% (95% CI 90.5% to 96.9%), while the overall rate of improvement or resolution of headache was 79.6% (95% CI 73.3% to 85.9%). Pulsatile tinnitus resolved in 90.3% (95% CI 83.8% to 96.70%), while the overall rate of recurrence of IIH symptoms after stenting was 9.8% (95% CI 6.7% to 13%). The rate of major complications was 1.9% (95% CI 0.07% to 3.1%).

Conclusions

Venous sinus stenting in patients with IIH who are refractory to medical therapy appears to have an excellent safety profile and is associated with significant improvements in headaches, pulsatile tinnitus, and papilledema.

Stent Survival and Stent-Adjacent Stenosis Rates following Venous Sinus Stenting for Idiopathic Intracranial Hypertension: A Systematic Review and Meta-Analysis

Background

Idiopathic intracranial hypertension (IIH) is characterized by an elevated intracranial pressure without any identifiable causative factor such as an intracranial mass. Dural venous sinus stenosis (DVSS) has been suggested to be associated with IIH.

Objective

We performed an updated systematic review and meta-analysis to determine clinical outcomes as well as stent survival and stent-adjacent stenosis rates in patients undergoing DVSS for the management of medically refractory IIH.

Methods

We searched PubMed, Embase, and Cochrane databases to identify prospective or retrospective cohorts or case series of patients with IIH treated with DVSS between 2000 and 2017.

Results

A total of 473 patients were included from 24 studies. Headache was present in 429 (91.8%) patients and resolved or improved in 319/413 (77.2%) after the procedure. Headache, papilledema, visual acuity, and tinnitus improved in 256/330 (77.6%), 247/288 (85.8%), 121/172 (70.3%), and 93/110 (84.5%) patients following DVSS at the final follow-up (mean of 18.3 months). In a meta-analysis of 395 patients with available follow-up data on stenting outcome (mean of 18.9 months), the stent survival and stent-adjacent stenosis rates were 84% (95% confidence interval [CI] 79-87%) and 14% (95% CI 11-18%), respectively. The rate of major neurological complications was less than 2%.

Conclusion

Stent-adjacent stenosis is an important complication following venous stenting in patients with DVSS and IIH. Further studies are needed to identify determinants of stent-adjacent stenosis and stent nonsurvival.

Recommendations for the selection and treatment of patients with idiopathic intracranial hypertension for venous sinus stenting

INTRODUCTION

Although venous sinus stenting (VSS) has emerged as a promising treatment option for patients with idiopathic intracranial hypertension (IIH) and associated venous sinus stenosis, there is considerable ambiguity regarding patient selection criteria, treatment protocols, and management strategies.

METHODS

An extensive literature review was performed to identify all reports of VSS in patients with IIH using PubMed. Recommendations for the selection and treatment of patients with IIH with VSS are outlined as determined based on author opinion from supporting studies. Due to the lack of randomized trials and few published prospective studies, standard grading scales for recommendations and level of evidence are not fully applicable and therefore a revised grading scale has been provided for recommendations.

RESULTS

The literature review identified a total of eight systematic reviews or meta-analyses and 29 published patient series on VSS. Recommendations for patient selection for diagnostic catheter angiography, angiography procedural considerations, stenting procedural considerations, and retreatment are provided based on the literature. Recommendations that were considered strong included: performance of venous sinus manometry to assess candidacy for treatment prior to stenting; administration of antiplatelet agents prior to stenting and for a follow-up period of at least 3-6 months; performance of post-stenting manometry to confirm resolution of pressure gradient; and performance of repeat angiography and manometry on patients with recurrence of symptoms after resolution with stenting to evaluate for recurrent stenosis.

CONCLUSION

VSS for patients with IIH with venous sinus stenosis is now an established and effective treatment option. These recommendations have been provided, based on a summative review of the available published literature, to assist in standardizing care for patients with IIH undergoing VSS.

The Significance and Reliability of Imaging Findings in Pseudotumor Cerebri

The objective of our study was to provide a comparative assessment of previously reported magnetic resonance imaging (MRI) parameters in primary and secondary pseudotumor cerebri (PTC) patients, to examine their diagnostic contribution, and to evaluate their association with symptoms, neuro-ophthalmological findings, laboratory results, and cerebrospinal fluid characteristics. Twenty-eight consecutive patients with PTC were included in the study. Age- and sex-matched 20 individuals with normal neurologic examination served as the control group. Modified Dandy Criteria were used for the diagnosis of PTC. Orbital and cranial MRI and MR venography of all patients and controls were assessed by three radiologists. According to our study, posterior flattening of the globe (64% sensitive, 100% specific), optic nerve sheath distention (46% sensitive, 100% specific), vertical tortuosity of the optic nerve (30% sensitive, 95% specific), and partial empty sella (43% sensitive, 100% specific) emerged as particularly valuable markers for a diagnosis of PTC.

Pressure variations in cerebral venous sinuses of idiopathic intracranial hypertension patients

PURPOSE

To evaluate the alteration of pressure characteristics in the cerebral venous sinuses before and after venous sinus stenting (VSS) using mean sinus pressures (MSPs), sinus pressure gradient (SPG), and sinus pressure pulsatility (SPP) parameters among the idiopathic intracranial hypertension (IIH) patients.

MATERIALS AND METHODS

Prospective evaluation of 45 consecutive IIH patients who underwent VSS at our institution. A written informed consent approved by the Weill Cornell Institutional Review Board was signed by the study participants. All patients (n = 45) were evaluated for MSPs and SPG. In a subgroup of 12 (n = 12) consecutive patients, SPP was measured. MSP was measured using microcatheter at superior sagittal sinus (SSS), transverse sinus (TS), and sigmoid sinus (SS). SPG was measured as trans-stenotic gradient and trans-torcular gradient. SPP was recorded in the dominant TS with a six French intermediate catheter. Statistical analysis was performed using paired student t-test and two sample t-tests tested for both equal and unequal variances. P values below 0.05 were considered significant.

RESULTS

The mean age of the study population was 30.6 ± 10 years (7-59 years) and 43 out of 45 are female patients. The mean weight and BMI of the study population were 96 ± 24.7 kg (30.8-144 kg) and 35.6 ± 8.3 kg/M² (16.4-51.4 kg/M²), respectively. VSS in IIH patients resulted in immediate reduction of MSP in the SSS {Δ Mean: -8.1 mm Hg [95% confidence interval (CI): -5.0-11.7 mm Hg], p < 0.001} and TS [Δ Mean: -11.8 mm Hg (95% CI: -7.5 to 13.4 mm Hg), p < 0.001] and increase of MSP in SS [Δ Mean: 7.5 mm Hg (95% CI: 6-10.1 mm Hg), p < 0.001]. Significant reduction of trans-stenotic SPG reduction [Δ Mean: -15.7 mm Hg (95% CI: -13.6-17.8 mm Hg), p < 0.001] and SPP [Δ Mean: -8 mm Hg (95% CI: -2.5-13.4 mm Hg), p < 0.05] was observed following VSS.

CONCLUSION

VSS resulted in immediate alteration of the cerebral venous sinus pressure measurements in patients with IIH.

Correlation between angiographic stenosis and physiologic venous sinus outflow obstruction in idiopathic intracranial hypertension

Introduction

The relationship between degree of angiographic venous sinus stenosis and the trans-stenosis pressure gradient magnitude in idiopathic intracranial hypertension (IIH) is poorly understood. The present study aimed to assess the utility of angiography, venography, and non-invasive imaging (MRV or CTV) for the diagnosis and characterization of clinically significant VSS.

Methods

Retrospective analysis of a prospectively collected database was performed to identify patients with medically refractory IIH who were evaluated by angiography and venous manometry for the presence of VSS with associated clinically significant pressure gradient. Angiographic stenosis was measured by two independent raters using novel methodology.

Results

Thirty-seven patients met inclusion criteria for the study. In total, 70% of patients had clinically significant pressure gradients and were selected for stenting. The optimal percentage stenosis for detection of a significant pressure gradient was 34% stenosis on venous phase arteriography (sensitivity 0.81 and specificity 0.91) and 31% stenosis on venography (0.92 and 0.73). For every 10% increase in stenosis, an approximate increase in pressure gradient of 3.5 mmHg is seen. MRV/CTV had a calculated sensitivity of 0.42, and a negative predictive value of 22%.

Conclusion

The degree of stenosis predictive of a clinically significant pressure gradient (30–35%) in the venous sinuses is considerably lower than the arterial stenosis at which pathologic hemodynamic alterations occur. While highly predictive of a venous pressure gradient when a stenosis is identified, non-invasive imaging does not appear to be a suitable diagnostic evaluation for the purpose of ruling out clinically significant cerebral VSS.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Fifty shades of gradients: does the pressure gradient in venous sinus stenting for idiopathic intracranial hypertension matter? A systematic review

OBJECTIVE

The role of venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH) is not well understood. The aim of this systematic review is to attempt to identify subsets of patients with IIH who will benefit from VSS based on the pressure gradients of their venous sinus stenosis.

METHODS

MEDLINE/PubMed was searched for studies reporting venous pressure gradients across the stenotic segment of the venous sinus, pre- and post-stent pressure gradients, and clinical outcomes after VSS. Findings are reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

From 32 eligible studies, a total of 186 patients were included in the analysis. Patients who had favorable outcomes had higher mean pressure gradients (22.8 ± 11.5 mm Hg vs 17.4 ± 8.0 mm Hg, p = 0.033) and higher changes in pressure gradients after stent placement (19.4 ± 10.0 mm Hg vs 12.0 ± 6.0 mm Hg, p = 0.006) compared with those with unfavorable outcomes. The post-stent pressure gradients between the 2 groups were not significantly different (2.8 ± 4.0 mm Hg vs 2.7 ± 2.0 mm Hg, p = 0.934). In a multivariate stepwise logistic regression controlling for age, sex, body mass index, CSF opening pressure, pre-stent pressure gradient, and post-stent pressure gradient, the change in pressure gradient with stent placement was found to be an independent predictor of favorable outcome (p = 0.028). Using a pressure gradient of 21 as a cutoff, 81/86 (94.2%) of patients with a gradient > 21 achieved favorable outcomes, compared with 82/100 (82.0%) of patients with a gradient ≤ 21 (p = 0.022).

CONCLUSIONS

There appears to be a relationship between the pressure gradient of venous sinus stenosis and the success of VSS in IIH. A randomized controlled trial would help elucidate this relationship and potentially guide patient selection.

Stenting of the Lateral Sinus in Idiopathic Intracranial Hypertension According to the Type of Stenosis

BACKGROUND

Over the past decade, stenting of lateral sinus stenosis has been used to treat idiopathic intracranial hypertension. Two types of stenoses have been identified: extrinsic and intrinsic.

OBJECTIVE

The aim of this study was to report the results of our use of this procedure to treat patients with extrinsic or intrinsic stenoses in idiopathic intracranial hypertension.

METHODS

We retrospectively studied clinical, radiological, and manometric data from patients with idiopathic intracranial hypertension who were treated at our institution between January 2009 and January 2015 by stenting of the lateral sinus.

RESULTS

Data were studied from 19 women and 2 men. Average body mass index was 29 kg/m 2 , and the median age at stenting was 33 years. Patients with extrinsic stenoses were younger than those with intrinsic stenoses. Transstenotic gradients measured with patients under general anesthesia were lower than those measured with patients under local anesthesia. In all cases, stenting was effective for papilledema and pulsatile tinnitus. Seventeen patients reporting headaches found that they disappeared completely after stenting. Two complications without long-term effects were reported.

CONCLUSION

Irrespective of the type of stenosis, stenting of lateral sinus stenoses is an effective treatment for intracranial hypertension symptoms. At our institution, this treatment has replaced draining of cerebrospinal fluid when treatment with acetazolamide has proved to be ineffective.

Imaging of Intracranial Pressure Disorders

Intracranial pressure (ICP) is the pressure inside the bony calvarium and can be affected by a variety of processes, such as intracranial masses and edema, obstruction or leakage of cerebrospinal fluid, and obstruction of venous outflow. This review focuses on the imaging of 2 important but less well understood ICP disorders: idiopathic intracranial hypertension and spontaneous intracranial hypotension. Both of these ICP disorders have salient imaging findings that are important to recognize to help prevent their misdiagnosis from other common neurological disorders.

Impaired cerebrospinal fluid pressure

Abnormalities of cerebrospinal fluid (CSF) pressure are relatively common and may lead to a variety of symptoms, with headache usually being the most prominent one. The clinical presentation of alterations in CSF pressure may vary significantly and show a striking similitude to several primary headache syndromes. While an increase in CSF pressure may be of primary or secondary origin, a pathologic decrease of CSF pressure is usually the result of a meningeal rupture with a resulting leakage of CSF. The pathophysiologic mechanisms of idiopathic intracranial hypertension (IIH) remain largely unknown. However recent evidence indicates that an abnormality in CSF outflow and absorption is likely to play a significant role. Treatment usually consists of a combination of weight loss and a pharmacologic approach using carbonic anhydrase inhibitors. Recent results of the first randomized, double-blind, placebo-controlled trial (RCT) with acetazolamide proved its efficacy in reducing headache and visual disturbances. Clinical evidence suggests efficacy for topiramate and furosemide but no RCT has been conducted to date to confirm these results. In contrast to IIH, spontaneous intracranial hypotension frequently remits spontaneously without specific treatment. If necessary, treatment options range from conservative methods to epidural blood or fibrin sealant patches and surgical interventions.