Meta-Analysis of CSF Diversion Procedures and Dural Venous Sinus Stenting in the Setting of Medically Refractory Idiopathic Intracranial Hypertension

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.

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

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.

Redefining treatment expectations: exploring mid- and long-term outcomes of venous sinus stenting in idiopathic intracranial hypertension

BACKGROUND

Venous sinus stenting (VSS) is recognized as a safe and effective intervention for medically-refractory idiopathic intracranial hypertension (IIH). However, its long-term efficacy remains uncertain.

METHODS

This retrospective review analyzed a single-center database of adult patients with severe, medically-refractory IIH, who underwent VSS and had minimum 3-month follow-up (FU). Patients were divided into three groups based on post-stenting symptom trajectories: group 1 (sustained improvement without relapse), group 2 (temporary improvement with relapse), and group 3 (no improvement).

RESULTS

Of 178 patients undergoing VSS, the majority were female (94%), with a median opening pressure (OP) of 31 cm H2O and trans-stenosis gradient of 14 mm Hg. Of these, 153 (86%) received transverse sinus (TS) stenting, and 19 (11%) underwent concurrent TS and superior sagittal sinus stenting. At a mean FU of 166 days, 53 patients (30%) showed long-term improvement without relapse (group 1). Symptomatic recurrence was noted in 101 patients (57%; group 2) within a mean FU of 390 days. Despite recurrent headache and tinnitus, the average OP reduction was 9.6 cm H2O on repeat lumbar puncture, with 75% showing papilledema improvement or resolution post-VSS. Only 17% required further surgical intervention.

CONCLUSIONS

The most common clinical outcome post-VSS in IIH patients is initial symptomatic improvement followed by symptom recurrence in about 60% at a mean of 274 days, despite a consistent intracranial pressure reduction. These findings can guide physicians in setting realistic expectations with patients regarding VSS outcomes.

Assessment of Reversibility of Transverse Venous Sinus Stenosis in Patients With Papilledema

BACKGROUND

Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema.

METHODS

This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices. Inclusion criteria were the presence of papilledema, as quantified by optical coherence tomography, and bilateral TVSS, which is considered typical of IH on neuroimaging. During follow-up, included patients must have had confirmation of papilledema resolution as well as subsequent neuroimaging after conservative treatment or cerebrospinal fluid flow diversion. Patients with dural sinus vein thrombosis or intrinsic stenosis from sinus trabeculations or significant arachnoid granulations were excluded from the study. Either CT venography or MRI/MR venography was reviewed by a fellowship-trained neuroradiologist, and the degree of stenosis was scored through the combined conduit score (CCS), as described by Farb et al. The primary outcome was to assess TVSS changes after resolution or improvement of papilledema.

RESULTS

From 435 patients, we identified a subset of 10 who satisfied all inclusion criteria. Our cohort comprised entirely women with a median age of 29.5 years and a median BMI of 32.5 kg/m2. Treatment consisted of acetazolamide in 7 patients, of which 1 had additional topiramate and 2 underwent cerebrospinal fluid flow diversion. Furthermore, 6 patients demonstrated significant weight loss during follow-up. For the primary outcome, 5 of 10 patients exhibited no appreciable TVSS change, and 5 patients demonstrated significant improvement in TVSS, of which 4 received conservative treatment only. Papilledema resolution or improvement was statistically significantly associated with increasing average CCS, TVSS diameter, and grade.

CONCLUSIONS

We were able to demonstrate that TVSS can be both irreversible and reversible in patients with resolved papilledema. The finding of TVSS reversibility from conservative treatment alone is novel and has important implications to optimize patient care. Future studies should work to identify factors associated with irreversible TVSS for subsequent targeted intervention and prevention.

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.

Surgical management of pseudotumor cerebri syndrome: A single center experience with endoscopic optic nerve decompression and CSF diversion procedures

OBJECTIVES

Pseudotumor cerebri syndrome (PTC) is a chronic disorder, which is initially treated by conservative measures, yet surgery is inevitable in case of progressive worsening of vision or headache despite medical treatment. The surgical management is controversial including CSF diversion procedures and optic decompression. The purpose of this study was to evaluate the efficacy of different surgeries in PTC and to present surgical outcomes in a single center.

METHODS

This retrospective study included the patients with PTC who were operated by endoscopic optic nerve decompression (EOND), ventriculoperitoneal (VP) and lumboperitoneal (LP) shunting. Surgical outcomes, i.e. visual acuity, visual field, papilledema and headache were compared according to type of surgery. Surgical complications were noted.

RESULTS

Seventeen of 36 patients were treated with shunting, 14 with EOND and 5 patients with both EOND and shunting. No statistical significance was observed between CSF diversion procedures and EOND concerning clinical outcomes. The improvement rate of papilledema was higher with VPS (p = 0574) while more patients benefitted from LPS regarding visual field and acuity (p = 0471 and p = 0718, respectively). The best treatment response for headache was in shunt implemented patients (VPS and LPS) with a rate of 88.2% followed by EOND (78.6%) and both surgeries (60%)(p = 0.294). Gender and BMI were significant predictors of improved papilledema (p = 0.034).

CONCLUSIONS

Our study demonstrated comparable results between shunting and EOND, regarding the efficacy on surgical outcomes. EOND is quite effective for headache besides its advantage on treatment-refractory visual loss. Shunting may offer sustained relief of symptoms when compared with EOND.

Multiple skull base defects in the setting of spontaneous cerebrospinal fluid rhinorrhea; a dual institution view

PURPOSE

Idiopathic intracranial hypertension (IIH) is a condition of high cerebrospinal fluid (CSF) pressure that presents with CSF leak. The implications of multiple skull base defects (SBD) and associated synchronous CSF leaks have not been previously explored.

MATERIALS AND METHODS

A dual institutional case-control study examined multiple SBD's and encephaloceles on the risk of CSF leak and postoperative failures post-repair. IIH patients with CSF leaks and IIH controls without leaks were selected retrospectively. Chi square analysis evaluated for statistically significant alterations in probability with CSF leak development.

RESULTS

192 patients were selected with 108 IIH controls and 84 spontaneous CSF leak cases. Signs and symptoms for IIH controls and CSF leak cases respectively were pulsatile tinnitus (60.2 % and 29.8 %), headaches (96.3 % and 63.1 %), papilledema (74.1 % and 12.5 %), visual field defects (60.8 % and 13 %) (p < 0.001). Encephalocele formation in controls was 3.7 % compared to cases at 91.6 % (p < 0.001). Multiple SBD's in controls compared cases was 0.9 % and 46.4 % respectively (p < 0.001). Subgroup analysis of CSF leak cases showed 15 patients with two CSF leak repairs due to a recurrence. 27 (39.1 %) single leak cases had multiple SDB's while 12 (80 %) recurrent leaks had multiple SDB's (p = 0.004).

CONCLUSIONS

Patients with radiographic evidence of multiple SBD's and encephaloceles represent a high-risk population with a propensity for CSF leaks. Secondary SBD's are common in patients with spontaneous CSF rhinorrhea and higher in patients with a recurrence.

Severe bilateral papilledema after sigmoid sinus constriction surgery: a case report

BACKGROUND

Papilledema is a common sign of various diseases in the eye. It could result from any conditions of increased intracranial pressure (ICP). Underlying the etiology of papilledema and appropriate treatment in time is essential.

CASE REPORT

We present a case of severe bilateral papilledema after sigmoid sinus constriction surgery. A 25-year-old female presented with a 1-month history of bilateral blurred vision, headache, and vomiting. The patient had a history of right-side sigmoid sinus constriction surgery for pulsatile tinnitus (PT) one month before in another hospital. Fundus examination showed severe bilateral papilledema. Lumbar puncture showed an elevated cerebrospinal fluid (CSF) opening pressure of 29 cm H2O. Neuroimaging examination demonstrated the right sigmoid sinus filling defect as changes after surgery. We referred the patient to the initial surgeon, who repaired the sigmoid sinus on the right side by removing the implanted gelatin sponge, as diuretic treatment could not be effective. Intracranial hypertension symptoms and signs improved soon after eliminating sigmoid sinus stenosis. Neuroimaging showed resolved right sigmoid sinus stenosis after the second surgery. CSF opening pressure was 14.5 cm H2O at the 1-month follow-up. Fundus examination showed entirely resolved papilledema. Three years of follow-up showed no recurrence.

CONCLUSIONS

This is the first clinical report of intracranial hypertension associated with sigmoid sinus constriction surgery. Although rare, rapid detection and adequate etiology management could lead to a good prognosis. It highlights the need for ophthalmologists to be aware of the diagnostic approach to papilledema and enhance cooperation with multidisciplinary departments. The most likely cause of the intracranial hypertension was dominant sinus surgical constriction by mechanical external compression, as confirmed by the complete clinical remission following the second operation to remove the implanted gelatin sponge. Thus, this case also highlights the importance of selecting the appropriate therapeutic option for PT. Surgical sinus constriction should no longer be considered a viable option for PT treatment.

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.

Idiopathic intracranial hypertension associated with polycystic ovarian syndrome, sensorineural hearing loss, and elevated inflammatory markers that lead to bilateral blindness: A case report with literature review

Background

Pseudotumor cerebri (PTC) or idiopathic intracranial hypertension (IIH) is characterized by elevated intracranial pressure without hydrocephalus or mass lesion, with normal cerebrospinal fluid (CSF) studies and neuroimaging. The exact cause remains uncertain, but potential mechanisms include increased CSF production, impaired CSF absorption, cerebral edema, and abnormal cerebral venous pressure gradients. Patients may present with various accompanying symptoms such as unilateral or bilateral visual obscuration, pulsatile tinnitus, back pain, dizziness, neck pain, blurred vision, cognitive difficulties, radicular pain, and typically intermittent horizontal diplopia.

Case Description

We report a case of a 32-year-old female who initially presented with chronic headaches and oligomenorrhea, which resulted in the diagnosis of polycystic ovary syndrome (PCOS) a few years before the initial diagnosis of PTC. Despite receiving maximum medical treatment and undergoing optic nerve sheath fenestration, the patient experienced complete bilateral vision loss. Nearly 5 years later, the patient sought care at our outpatient neurology clinic, presenting with symptoms including tinnitus, left-sided hearing loss, and joint pain with elevated inflammatory markers and headaches. The focus of this research was to discuss the pathophysiology of each of these comorbidities.

Conclusion

This case report aims to explore the pathophysiological relationships between PTC and concurrent comorbidities, including PCOS, sensorineural hearing loss, empty sella (ES) syndrome, and elevated inflammatory markers. Remarkably, no other PTC case with this unique constellation of concurrent comorbidities have been reported in existing medical literature. The case report underscores the critical importance of early diagnosis of IIH and prompt medical intervention, particularly in patients with PCOS experiencing chronic headaches.

Idiopathic Intracranial Hypertension with Disproportionately Enlarged Subarachnoid Space Hydrocephalus on Imaging

The pathophysiology of idiopathic intracranial hypertension (IIH) and idiopathic normal-pressure hydrocephalus (iNPH) differs in terms of cerebrospinal fluid (CSF) pressure and imaging-related characteristics. A 51-year-old man presented with optic nerve papillary edema, visual disturbance, bilateral abducens nerve palsy, and a wide-based gait. Imaging showed characteristic findings of IIH and disproportionately enlarged subarachnoid space hydrocephalus (DESH) - characteristic of iNPH. A CSF examination revealed marked CSF hypertension. IIH with iNPH-like imaging features (DESH) was diagnosed, and ventriculoperitoneal shunt surgery was performed. Postoperatively, the visual acuity and visual field improved. This report also describes the distinct and overlapping pathophysiological mechanisms of IIH and iNPH.

Stenting versus medical treatment for idiopathic intracranial hypertension: a matched-control study

BACKGROUND

This prospective cohort study compared the outcomes of stenting and medical treatment for patients with idiopathic intracranial hypertension (IIH) and venous sinus stenosis (VSS).

METHODS

In this single-center cohort study, patients with IIH and VSS were evaluated between January 2014 and December 2019 with follow-up periods of 1, 3, and 6 months. The patients received either stenting or medical treatment. The two groups underwent 1:1 matching using propensity score analysis, and the clinical outcomes were compared.

RESULTS

Following 1:1 matching, 36 patients who underwent stenting and 36 who underwent medical treatment were matched. The median improvements in the papilledema Frisén grade were greater in the stenting group at 1 month (-2 vs 0), 3 months (-3 vs -1), and 6 months (-3 vs -1) than in the medical treatment group. Patients who received stenting treatment had a significantly higher prevalence of complete resolution of their respective symptoms (headache, tinnitus, or visual disturbances) at 3 months (58.3% vs 13.9%, OR 8.68, 95% CI 2.74 to 27.52) and 6 months (80.6% vs 22.2%, OR 14.50, 95% CI 4.64 to 45.32) than those receiving medical treatment.

CONCLUSIONS

This matched-control study shows that stenting has a greater efficacy rate and rapid resolution of papilledema and its respective symptoms compared with medical treatment.

Venous sinus stenting for the treatment of acute blindness in a patient with idiopathic intracranial hypertension

We present a case of acute onset of blindness treated with venous sinus stenting in the hyperacute period (24-48 h). The patient had not been diagnosed previously with idiopathic intracranial hypertension and presented at an outside facility with a short history of headache, nausea, vomiting and visual deficits. Initial management included lumbar punctures for pressure relief. Unfortunately, the patient's condition deteriorated and she experienced the rapid onset of blindness. Within 24-48 h of blindness onset, she was transferred to our institution for emergent endovascular stenting of the venous sinuses. The intervention resulted in improvement of symptoms and recovery of visual acuity over a short-term follow-up period.

Emergent cerebral venous stenting: A valid treatment option for fulminant idiopathic intracranial hypertension

BACKGROUND

Fulminant idiopathic intracranial hypertension (FIIH) is characterized by rapid, severe, progressive vision loss and often treated surgically. Cerebral transverse venous stenting (CTVS) is efficacious in IIH patients, but emergent CTVS in FIIH is rarely reported. We present our experience with emergent CTVS in patients with FIIH.

METHODS

Since 01/2019, an institutional protocol allowed emergent CTVS in FIIH patients with bilateral transverse sinus stenosis and gradient pressure > 15 on digital subtraction angiography (DSA). We retrospectively analyzed a prospective registry of all IIH patients with details of neurological and neuro-ophthalmological assessments before and after treatment, and subjective assessments of headache and tinnitus were made pre-and post-procedure.

RESULTS

259 IIH patients, including 49 who underwent CTVS, were registered. Among them, five female patients met inclusion criteria for FIIH and underwent emergent CTVS. FIIH patients were younger (18.8 ± 1.64 vs 27.7 ± 4.85, p < 0.01), mean BMI was lower (30.8 ± 10.57 vs 34.6 ± 4.3, p < 0.01), and lumbar puncture opening pressure higher (454 ± vs 361 ± 99.4, p < 0.01) than that of IIH patients. They presented with acute visual loss, severe headache, papilledema, significant bilateral transverse sinus stenosis on CT-venography, and mean dominant side gradient pressure of 26.4 ± 6.2 on DSA. CTVS was performed without significant complications, resulting in remarkable improvement in headache, optical coherence tomography, and visual fields within 1 week. At 1-year follow-up (four patients) and 6-month follow-up (1 patient), there was complete resolution of papilledema and headache, and marked improvement in visual acuity.

CONCLUSIONS

In these patients, emergent-CTVS was a safe and effective treatment option for FIIH. Further evaluation is warranted.

Blood Flow Velocity: a Decision Tool for Stenting Indication in Venous Pulsatile Tinnitus

BACKGROUND AND PURPOSE

Lateral sinus stenosis is the most common cause of venous pulsatile tinnitus (VPT). Stenting is an effective treatment after demonstration of a trans-stenotic pressure gradient; however, pressure measurement has many technical limitations. In 2018, a study showed that a combined approach with intravascular velocity measurement could be effective in identifying most appropriate candidates for stenting. The aim of the present study was to evaluate a new strategy using this biomarker for the indication of stenting even without a significant pressure gradient.

MATERIAL AND METHODS

Consecutive patients with disabling VPT were included from 2016 to 2019 and analyzed retrospectively. Intrasinusal pressures were measured and blood flow velocities (with a dual-sensor guidewire) were used for the indication of stenting independent of the pressure gradient. We evaluated the clinical outcome after stenting based on this new biomarker.

RESULTS

A total of 41 patients were treated according to this strategy. At last follow-up (mean = 30.2 months), 32/33 patients (97%) treated by stenting showed complete resolution or a significant decrease in VPT intensity. The use of velocity as the threshold for indicating stenting identified 8 patients (24%) missed by the pressure gradient. Their clinical outcome after stenting was excellent and no complications occurred.

CONCLUSION

Measurement of sinus blood flow velocity provides a hemodynamic explanation of disease and may be a better tool than pressure gradient for the indication of stenting in VPT.

Intracranial venous stenting for idiopathic intracranial hypertension

INTRODUCTION

There is increasing evidence in the literature to support venous sinus stenting in patients with idiopathic intracranial hypertension who fail first-line therapy. Venous sinus stenting is a safe and successful technique compared with cerebrospinal fluid diversion procedures. This study examines the clinical outcomes of patients post intracranial venous stenting for intracranial hypertension across three tertiary hospitals in Western Australia.

METHODS

A retrospective analysis was performed on 83 consecutive patients treated with intracranial venous stenting for IIH at three tertiary hospitals from October 2013 to March 2020. Data were collected from outpatient clinic letters, electronic discharge letters, electronic radiological imaging and procedural reports.

RESULTS

89.2% patients were able to cease Acetazolomide post stenting. 78.3% patients reported resolution of headaches. 84.3% patients demonstrated resolution of their papilloedema. 91.6% patients demonstrated improvement of their visual acuity. Compared with a recent meta-analysis by Satti and Chaudry in 2015, our results demonstrated a higher technical success rate and lower complication rates.

CONCLUSION

Our study findings support the paradigm shift from CSF diversion procedures to venous sinus stenting in patients with IIH who fail first-line therapy. Venous sinus stenting has a high technical success rate and significantly lower complication rates than other invasive treatments.

A Case of Bilateral Papilledema With Improved Clinical Symptoms by Venous Stenting for Superior Sagittal Sinus Stenosis

Superior sagittal sinus (SSS) obstruction causes intracranial hypertension, often requiring surgical stenting. Consensus on treating brain venous sinus stenosis, another cause, is lacking. This study reports a case of SSS stenosis and intracranial hypertension treated with venous stenting, improving bilateral papilledema. A 51-year-old with a headache and visual disturbance had papilledema and visual field loss. MR venography showed SSS stenosis, leading to a neurosurgery referral. Lumbar puncture confirmed intracranial hypertension (>35 cmH2O), prompting venous stenting. Post-procedure, papilledema, headache, and visual field loss improved. Venous stenting could be effective for SSS stenosis with clinically proven or recurrent pressure differences. Further cases are needed for standardization.

Endoscopic endonasal optic nerve sheath decompression (EONSD) for idiopathic intracranial hypertension: Technical details and meta-analysis

BACKGROUND

The neurosurgical management of idiopathic intracranial hypertension (IIH) remains controversial. Although shunting and newer endovascular stenting techniques are part of the neurosurgical armamentarium to treat medically refractory IIH symptoms, optic nerve sheath fenestration has traditionally been performed by ophthalmologists.

OBJECTIVE

We present a detailed cadaveric dissection that simulates the endoscopic endonasal optic nerve sheath decompression (EONSD) technique along with the literature review.

METHODS

EONSD was performed in four freshly injected cadaveric specimens. Additionally, a systematic review from different electronic databases has been done.

RESULTS

Bilateral EONSD was performed in all specimens without significant technical difficulties. Based on our experience, there is no need to expose the periorbita or orbital apex. The primary anatomic landmarks were the optic canal, the lateral opticocarotid recess, the tuberculum, the limbus, and the clinoid segment of the internal carotid artery. Based on the systematic review, 68 patients (77.9% female) underwent EONSD, with a mean age of 33.4 ± 6.9 years in adult patients. Follow-up ranged from 3 to 58 months across different studies. The pooled meta-analysis showed headache, papilledema, and visual disturbance improvement in 78% [95%CI 0.65-0.90], 72% [95%CI 0.61-0.83], and 88% [95%CI 0.80-0.96] of cases who underwent EONSD, respectively. The subgroup analysis showed there was no statistically significant difference between unilateral and bilateral EONSD in terms of different measured outcomes.

CONCLUSION

EONSD is a feasible surgical procedure that may obviate the need for shunting in patients with IIH. Although clinical studies showed that EONSD is a safe and effective technique, further studies are required to establish the preferences of either unilateral or bilateral approaches.

"Idiopathic" intracranial hypertension: An update from neurointerventional research for clinicians

BACKGROUND

The recognition of venous sinus stenosis as a contributing factor in the majority of patients with idiopathic intracranial hypertension coupled with increasing cerebral venography and venous sinus stenting experience have dramatically improved our understanding of the pathophysiologic mechanisms driving this disease. There is now a dense, growing body of research in the neurointerventional literature detailing anatomical and physiological mechanisms of disease which has not been widely disseminated among clinicians.

METHODS

A literature search was conducted, covering the most recent neurointerventional literature on idiopathic intracranial hypertension, the pathophysiology of idiopathic intracranial hypertension, and management strategies (including venous sinus stenting), and subsequently summarized to provide a comprehensive review of the most recently published studies on idiopathic intracranial hypertension pathophysiology and management.

CONCLUSION

Recent studies in the neurointerventional literature have greatly improved our understanding of the pathophysiologic mechanisms causing idiopathic intracranial hypertension and its associated conditions. The ability to make individualized, patient-specific treatment approaches has been made possible by advances in our understanding of how venous sinus stenosis and cerebral venous hypertension fundamentally contribute to idiopathic intracranial hypertension.

Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review

Cerebrospinal fluid leak (CSFL) is a rare pathological condition which requires prompt and adequate management due to the high rate of associated major complications. At present, CSFL can be successfully treated through endoscopic endonasal approaches with success rates higher than 90%. Despite this, CSFL recurrence may occur, and its management is critical and still represents a matter of debate. A systematic review of the literature on the management of recurrent CSFL was conducted. It included a cohort of 1,083 cases of CSFL treated with surgical or conservative approaches; 112 cases of recurrence were reported for an overall recurrence rate of 10.3%. Most of the leaks were localised in the anterior skull base (68.3%) and identification of recurrent CSFL may be troublesome. Therefore, the entire skull base must be meticulously examined and long-term follow-up is mandatory. The risk for CSFL recurrence is higher in patients affected by idiopathic intracranial hypertension (IIH), but its role in CSFL recurrence is yet to be understood. Recurrent CSFL must be repaired as soon as possible in order to reduce the risk of intracranial complications. The use of early post-operative CSF diversion by lumbar drain (LD) is currently a matter of debate even in case of CSFL recurrences.

Optic atrophy secondary to minocycline-induced idiopathic intracranial hypertension

An early adolescent female presented with blurry vision, ocular 'fullness', pulsatile tinnitus and gait difficulty due to poor vision. She was found to have florid grade V papilloedema, 2 months after the use of minocycline for the treatment of confluent and reticulated papillomatosis for 2 months. MRI of the brain without contrast showed fullness of the optic nerve heads concerning for increased intracranial pressure, which was confirmed on lumbar puncture with an opening pressure greater than 55 cm H2O. She was initially started on acetazolamide, but due to high opening pressure and severity of visual loss, a lumboperitoneal shunt was placed in 3 days. This was complicated by a shunt tubal migration 4 months later, leading to worsening vision of 20/400 in both eyes for which she underwent shunt revision. By the time she presented to the neuro-ophthalmology clinic, she was legally blind with her exam consistent with bilateral optic atrophy.

Optic nerve sheath fenestration for treating papilloedema in the era of cerebral venous sinus stenting

BACKGROUND

Pseudotumour cerebri (PTC) is the syndrome of intracranial hypertension without intracranial mass or hydrocephalus and is the commonest cause of papilloedema seen in many eye clinics. In the last 10 years, we have increasingly used TSS in patients whose papilloedema was not well controlled with medical treatment and have done fewer ONSFs. Here, we review our experience at Royal Prince Alfred Hospital Sydney with ONSF in 35 patients over the period 2002-2021.

METHODS

Retrospective case series of 35 patients, 30 of whom had primary PTC [i.e., idiopathic intracranial hypertension (IIH)] and 5 with secondary PTC.

RESULTS

Eighteen patients had bilateral ONSF and 17 patients unilateral ONSF, in each case of the worse eye. Thirteen patients then underwent transverse sinus stenting (TSS), in each case following ONSF. The primary outcome measures were visual acuity (VA) and mean deviation (MD) on visual field (VF) testing. MD improved by 5 dB or more in 34 of 70 total eyes (48.6%); VA improved by 0.2 logMAR (two lines on Snellen chart) or more in 21 eyes (30%), and by both in 15 eyes (21.4%). Final MD was -10 dB or better in 38 eyes (54.3%); final VA was 0.3 (6/12) or better in 54 eyes (77.1%), and both in 39 eyes (55.7%).

CONCLUSIONS

The results confirm that ONSF can relieve papilloedoema in both eyes and improve both VF and VA, even in cases of fulminant PTC with severe acute visual impairment.

Venous Sinus Stenting: Safety and Health Care Resource Evaluation for Optimal Recovery in an Evolving Health Care Environment

BACKGROUND

Increasing evidence supports the effectiveness of venous sinus stenting (VSS) with favorable outcomes, safety, and expenses compared with shunting for idiopathic intracranial hypertension. Yet, no evidence is available regarding optimal postoperative recovery, which has increasing importance with the burdens on health care imposed by the coronavirus disease 2019 pandemic. We examined adverse events and costs after VSS and propose an optimal recovery pathway to maximize patient safety and reduce stress on health care resources.

METHODS

A retrospective review was undertaken of elective VSS operations performed from May 2008 to August 2021 at a single institution. Primary data included hospital length of stay, intensive care unit (ICU) length of stay, adverse events, need for ICU interventions, and hospital costs.

RESULTS

Fifty-three patients (98.1% female) met the inclusion criteria. Of these patients, 51 (96.2%) were discharged on postoperative day (POD) 1 and 2 patients were discharged on POD 2. Both patients discharged on POD 2 remained because of groin hematomas from femoral artery access. There were no major complications or care that required an ICU. Eight patients (15.1%) were lateralized to other ICUs or remained in a postanesthesia care unit because the neurosciences ICU was above capacity. Total estimated cost for initial recovery day in a neurosciences ICU room was $2361 versus $882 for a neurosurgery/neurology ward room. In our cohort, ward convalescence would save an estimated $79,866 for bed placement alone and increase ICU bed availability.

CONCLUSIONS

Our findings reaffirm the safety of VSS. These patients should recover on a neurosurgery/neurology ward, which would save health care costs and increase ICU bed availability.

Thecoperitoneal Shunts—Our 20 Years Experience

Introduction The thecoperitoneal shunt is a modality of cerebrospinal fluid (CSF) diversion used to treat various clinical conditions such as idiopathic intracranial hypertension (IIH), normal pressure hydrocephalus (NPH), and CSF leaks. There is a wide variability in the data regarding the utility and complications associated with it. We thus reviewed the outcomes and complications of the shunt done in our setting.

Methodology The study is a retrospective review of all the thecoperitoneal shunts performed at NIMHANS (National Institute of Mental Health and Neurosciences) from January 2000 to December 2020. The demographic details, clinical profile, indications for the shunt, magnetic resonance imaging, follow-up and complications, and shunt revisions were collected and analyzed.

Results Three-hundred twelve patients underwent shunt primarily at our institute. The mean follow-up of the patients was 5.2 years. The indications include pseudomeningocele in 31.4%, CSF leak from surgical site in 25.3%, IIH in 17.6%, and NPH in 7.3% patients.

The shunt was more effective in pseudomeningocele in up to 95% and CSF leaks in 91% compared to 64‰ in IIH, though it is not significant (p > 0.05). The complication rate was 17% that included shunt block, wound CSF leak, infection, and subdural hygromas. The shunt malfunction was seen in 14.69% patients who underwent revision.

Conclusion Thecoperitoneal shunt is a useful treatment option for various pathologies including IIH, NPH, and wound CSF leaks. They have good clinical outcomes and acceptable revision rates especially in conditions with slit ventricle. The complications such as low-pressure headache can be overcome by using adjuncts as programmable valve or antisiphon device.

Optic Nerve Sheath Fenestration for Progressive Visual Loss in Cerebral Venous Sinus Thrombosis: A Long-Term Retrospective Observational Study

INTRODUCTION

Progressive cerebral venous sinus thrombosis (CVST)-induced visual loss remains problematic, despite decreasing overall mortality owing to early diagnosis and aggressive treatment. Optic nerve sheath fenestration (ONSF) improves or stabilizes visual function in patients with idiopathic intracranial hypertension; however, its role in CVST awaits elucidation. We evaluated the efficacy and safety of ONSF in resolving CVST-induced visual impairment based on long-term observation.

METHODS

This observational study included 18 patients with progressive CVST-induced visual loss, who had undergone ONSF between 2012 and 2021. Patients received maximum medical therapy, including anticoagulants and intracranial pressure (ICP)-lowering medications. The best-corrected visual acuity (BCVA), visual fields (VFs), and optic nerve head were assessed at baseline, at 1 week after ONSF, and over 6 months after ONSF. Activities of daily living (ADL) and National Eye Institute Visual Function Questionnaire-25 (VFQ-25) scores were assessed at final follow-up.

RESULTS

Thirty-one ONSF-treated eyes of 18 patients were included. The mean follow-up duration was 35.6 months (range 1 week-8 years). Two patients were lost to follow-up. Before ONSF, all patients were still experiencing progressive visual loss despite receiving adequate anticoagulation and ICP-lowering therapy. Postoperative BCVA remained stable or improved in 25/31 eyes (80.6%) 1 week postoperatively and 17/28 eyes (60.7%) upon final follow-up. All papilledema resolved postoperatively. No complications were reported except for one transient postoperative diplopia. The median ADL score was 100 (range 25-100), and the mean total VFQ-25 score was 40.6 (range 9.5-87.3).

CONCLUSION

This was the largest study to describe ONSF's role in CVST based on a long-term follow-up. Considering its efficacy and favorable safety, ONSF can be considered an important adjunctive approach to resolving progressive visual loss of CVST patients, on the basis of anticoagulation and ICP-lowering therapy.

Flow patterns in the venous sinus of pulsatile tinnitus patients with transverse sinus stenosis and underlying vortical flow as a causative factor

BACKGROUND

Transverse sinus stenosis (TSS) is commonly found in Pulsatile Tinnitus (PT) patients. Vortex flow is prominent in venous sinus with stenosis, and so it is important to determine the distribution and strength of the vortical flow to understand its influence on the occurrence of PT.

METHODS

In this study, by using computational fluid dynamics for hemodynamic analysis in patient-specific geometries based on Magnetic Resonance Imaging (MRI), we have investigated the blood flow within the venous sinus of 16 subjects with PT. We have employed both laminar and turbulent flow models for simulations, to obtain (i) streamlines of velocity distribution in the venous sinus, and (ii) pressure distributions of flow patterns in the venous sinus. Then, hemodynamic analysis in the venous sinus recirculation zone was carried out, to determine the flow patterns at the junction of transverse sinuses and sigmoid sinuses. Finally, we have proposed a new model for turbulence evaluation based on the regression analysis of anatomic and hemodynamics parameters.

RESULTS

Correlation analysis between the anatomical parameters and the hemodynamic parameters has shown that stenosis at the transverse sinus was the main factor in the local hemodynamics variation in the venous sinus of patients; in this context, it is shown that vorticity can be used as a prime indicator of the severity of the stenosis function. Our results have shown a significant correlation between the vorticity and the stenotic maximum velocity (SMV) (r = 0.282, p = 0.004). Then, a parameterized prediction model is proposed to determine the vorticity in terms of flow and anatomic variables, termed as the turbulence eddy prediction model (TEP model). Our result have shown that the TEP model is sensitive to the dominant flow distribution, with a high correlation to the flow-based vorticity (r = 0.809, p = 0.009).

CONCLUSIONS

The quantification of the vorticity (as both vorticity and MVV) in the downstream of TSS could be a marker for indication of turbulent energy at the transverse-sigmoid sinus, which could potentially serve as a hemodynamic marker for the functional assessment of the PT-related TSS.

Technical and clinical success after venous sinus stenting for treatment of idiopathic intracranial hypertension using a novel guide catheter for access: Case series and initial multi-center experience

INTRODUCTION

Venous sinus stenting is a well established alternative to cerebrospinal fluid diversion for the treatment of idiopathic intracranial hypertension (IIH) with associated venous sinus stenosis. During this procedure, distal guide catheter placement within the venous sinuses may be desirable to facilitate stent delivery. We report our initial experience using the TracStar LDP™ (Imperative Care, Campbell, USA, 0.088-inch inner diameter) as the guide catheter for intracranial access during venous sinus stenting.

METHODS

A multi-institutional retrospective chart review of a prospectively maintained IRB-approved database was performed. Consecutive patients who underwent venous sinus stenting from 1/1/2020-9/6/2021 for IIH were included. Patient characteristics, procedural details, TracStar distal reach, outcomes, and complications were collected and analyzed.

RESULTS

Fifty-eight patients were included. The mean age was 33.8 years and 93.1% of patients were female. Visual changes prompted evaluation in 86.2% of patients. Stent placement was successful in all patients. The TracStar LDP catheter was advanced to the location of stent placement in 97.9% of cases in which it was attempted. The large 0.088-inch inner diameter lumen enabled compatibility with all desired stent sizes ranging from six to 10 millimeters. Gradient pressure across transverse sinus stenosis dropped from an average of 19.5 mmHg pre-procedure to 1.7 mmHg post-stent placement (p < 0.001). Clinical improvement was achieved in 87.9% (51/58) of patients. There were no catheter-related complications.

CONCLUSION

The TracStar LDP is a safe and effective access platform for reaching treatment locations in patients who present with idiopathic intracranial hypertension and who are candidates for venous sinus stent placement.

Dural Venous Sinus Stenting in Idiopathic Intracranial Hypertension: A National Database Study of 541 Patients

BACKGROUND

Dural venous sinus stenting (VSS) is an effective intervention for patients with idiopathic intracranial hypertension (IIH) refractory to medical treatment. Our goal was to evaluate the efficacy by utilizing a large multi-institutional sample.

METHODS

Five hundred forty-one patients >18 years old who underwent VSS within 3 years of IIH diagnosis were queried using Current Procedural Terminology and International Classification of Diseases, Tenth Revision codes from the TriNetX Analytics Network. Patient demographics, baseline symptoms, procedures, and clinical outcomes were evaluated within 1 year postoperatively. Outcomes examined were headache, tinnitus, blindness/low vision, optic nerve sheath fenestration (ONSF), cerebrospinal fluid (CSF) shunt, and use of medications (acetazolamide, methazolamide, furosemide, topiramate, tricyclic antidepressants, and valproate) for IIH. Prestent and poststent data were compared using Fisher exact test, and the odds ratios were computed using the Baptista-Pike method.

RESULTS

The mean age at VSS was 36.7 ± 10.6; 92% were female, 65% of patients were Caucasian, 25% were Black/African American, 1% were Asian, and 9% were of other/unknown race. Within the 1-year follow-up, acetazolamide and topiramate use were significantly reduced post-VSS (P < 0.0001∗; odds ratio, 0.45; confidence interval, 0.35-0.57 and P = 0.03∗; odds ratio, 0.71; confidence interval, 0.52-0.95, respectively). Also, headaches, visual disturbance, dizziness/giddiness, and tinnitus significantly improved post-VSS (P < 0.005∗). Finally, the number of CSF shunt procedures and ONSF procedures demonstrated no significant change post-VSS (P > 0.05).

CONCLUSIONS

VSS is an effective and safe procedure resulting in significant improvement of headaches, visual impairment, dizziness, and tinnitus, acetazolamide and topiramate usage were lower after VSS in patients with IIH. The paucity of pre-VSS and post-VSS CSF shunt and ONSF procedure data does not provide enough evidence to establish significance.

Cerebrospinal Fluid Shunting for Idiopathic Intracranial Hypertension: A Systematic Review, Meta-Analysis, and Implications for a Modern Management Protocol

BACKGROUND

Cerebrospinal fluid (CSF) shunting is widely used in refractory idiopathic intracranial hypotension (IIH). Although multiple reviews have assessed its efficacy compared with other surgical treatments, there is no detailed analysis that evaluates the clinical outcomes after CSF shunting.

OBJECTIVE

To conduct a meta-analysis of the clinical impact of CSF shunting for refractory IIH and use this in conjunction with existing information on other treatment modalities to develop a modern management protocol.

METHODS

PubMed and Embase were systematically searched for studies describing CSF shunting for medically refractory IIH. Relevant information including study characteristics, patient demographics, clinical outcomes, periprocedural complications, and long-term outcomes were subjected to meta-analysis.

RESULTS

Fifteen studies published between 1988 and 2019 met our inclusion and exclusion criteria, providing 372 patients for analysis. The mean age was 31.2 years (range 0.5-71) with 83.6% being female. The average follow-up was 33.9 months (range 0-278 months). The overall rate of improvement in headache, papilledema, and visual impairment was 91% (95% CI 84%-97%), 96% (95% CI 85%-100%), and 85% (95% CI 72%-95%), respectively. Of 372 patients, 155 had 436 revisions; the overall revision rate was 42% (95% CI 26%-59%). There was no significant correlation between average follow-up duration and revision rates in studies ( P = .627). Periprocedural low-pressure headaches were noted in 74 patients (20%; 95% CI 11%-32%).

CONCLUSION

CSF shunting for IIH is associated with significant improvement in clinical symptoms. Shunting rarely causes periprocedural complications except overdrainage-related low-pressure headache. However, CSF shunting has a relatively high revision rate.

Visual recovery after unilateral optic nerve sheath fenestration for pseudotumor cerebri syndrome

PURPOSE

To evaluate the effect of optic nerve sheath fenestration (ONSF) on the rate of visual function improvement in patients with pseudotumor cerebri syndrome (PTCS).

METHODS

Retrospective chart review of patients with PTCS who underwent ONSF between 1998 and 2017. Visual function was evaluated by evaluating visual field (VF), mean deviation (MD), retinal nerve fiber layer (RNFL) thickness, papilledema grade, and visual acuity (VA) prior to and after ONSF.

RESULTS

Seventeen female patients aged 17 to 36 years underwent unilateral ONSF. Follow-up averaged 40.1 months. VF MD improved steadily in both eyes up to 12 months. Average RNFL thickness improved in the operated eye from 347 ± 166 mm to 92 ± 27 mm (p < .001) and the non-operated eyes from 306 ± 165 mm to 109 ± 46 mm (p < .001). The grade of papilledema improved in the operated eye from 3.3 ± 1.3 to 0.3 ± 0.7 and the non-operated eye from 3.0 ± 1.6 to 0.18 ± 0.4. There was an exponential rate of improvement in papilledema and RNFL thickness, with the greatest improvement occurring within the first 30 days. Average visual acuity remained intact in both eyes before and after surgery.

CONCLUSIONS

ONSF in appropriately selected patients leads to rapid improvement in papilledema and a steady recovery in VF.

Idiopathic intracranial hypertension imaging approaches and the implications in patient management

Idiopathic intracranial hypertension (IIH) represents a clinical disease entity without a clear etiology, that if left untreated, can result in severe outcomes, including permanent vision loss. For this reason, early diagnosis and treatment is necessary. Historically, the role of cross-sectional imaging has been to rule out secondary or emergent causes of increased intracranial pressure, including tumor, infection, hydrocephalus, or venous thrombosis. MRI and MRV, however, can serve as valuable imaging tools to not only rule out causes for secondary intracranial hypertension but can also detect indirect signs of IIH resultant from increased intracranial pressure, and demonstrate potentially treatable sinus venous stenosis. Digital subtraction venographic imaging also plays a central role in both diagnosis and treatment, providing enhanced anatomic delineation and temporal flow evaluation, quantitative assessment of the pressure gradient across a venous stenosis, treatment guidance, and immediate opportunity for endovascular therapy. In this review, we discuss the multiple modalities for imaging IIH, their limitations, and their contributions to the management of IIH.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

Optic Disc Edema and Elevated Intracranial Pressure (ICP): A Comprehensive Review of Papilledema

Papilledema is a swelling of the optic disc secondary to elevated intracranial pressure (ICP). We analyzed 79 peer-review journal articles and provided a concise summary of the etiology, epidemiology, pathophysiology, clinical presentation, evaluation, natural history, differential diagnosis, treatment, and prognosis of papilledema. Only studies written in English with the full text available were included. Although many etiologies of papilledema exist, idiopathic intracranial hypertension is the most common and, thus, a large focus of this review.

Diagnostic Approach to Pulsatile Tinnitus: A Narrative Review

Importance

Pulsatile tinnitus is a debilitating symptom affecting millions of Americans and can be a harbinger of hemorrhagic or ischemic stroke. Careful diagnostic evaluation of pulsatile tinnitus is critical in providing optimal care and guiding the appropriate treatment strategy.

Observations

An underlying cause of pulsatile tinnitus can be identified in more than 70% of patients with a thorough evaluation. We advocate categorizing the myriad causes of pulsatile tinnitus into structural, metabolic, and vascular groups. Structural causes of pulsatile tinnitus include neoplasms and temporal bone pathologic abnormalities. Metabolic causes of pulsatile tinnitus include ototoxic medications and systemic causes of high cardiac output. Vascular causes of pulsatile tinnitus include idiopathic intracranial hypertension and dural arteriovenous fistulas. This categorization facilitates a practical evaluation, referral, and treatment pattern.

Conclusions and Relevance

Categorizing the underlying cause of pulsatile tinnitus ensures that dangerous causes of pulsatile tinnitus are not missed, and that patients receive the appropriate care from the proper specialist when needed.

Advances in the Understanding of the Complex Role of Venous Sinus Stenosis in Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a disorder characterized by elevated intracranial pressure (ICP) that predominantly affects young obese women. IIH is a diagnosis of exclusion. That is, if increased ICP is suspected, magnetic resonance imaging and magnetic resonance venography of the brain are recommended to exclude secondary causes. Imaging findings, such as empty sella, orbital findings, meningocele, and encephalocele, are not diagnostic of ICP, nor does their absence exclude ICP either. Therefore, venous manometry is recommended as the gold standard for evaluation, regardless of previous anatomic imaging results. Venous manometry is an invasive examination that is frequently applied to derive physiologic information concerning the nature of the pressure gradient. However, the pathogenesis of IIH has not been fully elucidated. The presence of venous sinus stenosis in a subset of patients has provided some support for the potential mechanisms underlying this condition. Hence, this review provides an up‐to‐date discussion on the potential pathogenic mechanisms of IIH with a special focus on venous sinus stenosis.

New Options (or not) for Treatment of Idiopathic Intracranial Hypertension

PURPOSE OF REVIEW

Idiopathic intracranial hypertension (IIH) is a disorder primarily affecting obese women of childbearing age and, if left untreated, can lead to irreversible vision loss. No consensus exists on the best management strategy for IIH. Weight loss is advocated and few useful medical options exist. There is an unmet need to discover new treatment options for this increasingly prevalent condition. This article reviews the recent advances and research on the treatment of IIH.

RECENT FINDINGS

Venous sinus stenting (VSS) is now performed in many experienced centers, and there is growing interest in bariatric surgery as a treatment modality. Newly approved anti-obesity drugs are showing effectiveness in weight loss, and novel targeted disease-modifying IIH therapies are being explored. Further evaluation of these novel therapeutic strategies as well as studies exploring the use of anti-obesity drugs in IIH is needed. While VSS is gaining popularity due to its efficacy and low complication rate, there is insufficient evidence to support any surgical procedure over another. Bariatric surgery is appealing for patients with non-sight-threatening IIH and needs to be further explored.

Management of vascular causes of pulsatile tinnitus

Pulsatile tinnitus is a debilitating symptom affecting millions of Americans and can be a harbinger of hemorrhagic or ischemic stroke. Careful diagnostic evaluation of pulsatile tinnitus is critical in providing optimal care and guiding the appropriate treatment strategy. When a vascular cause of pulsatile tinnitus has been established, attention must be focused on the patient's risk of hemorrhagic stroke, ischemic stroke, or blindness, as well as the risks of the available treatment options, in order to guide decision-making. Herein we review our approach to management of the vascular causes of pulsatile tinnitus and provide a literature review while highlighting gaps in our current knowledge and evidence basis.

Idiopathic Intracranial Hypertension - Challenges and Pearls

Idiopathic intracranial hypertension (IIH) is defined as a syndrome of raised intracranial pressure with normal imaging of the brain and cerebrospinal fluid (CSF) composition. There is a rising incidence and prevalence of this disease related to the increased prevalence of obesity. It typically affects women of working age, and headache is the predominant morbidity in over 90%. The disease is also more prevalent in young males. There are many controversies and myths that surround IIH. There are currently few treatment options for IIH, management is typically medical with those experiencing progressive visual loss undergoing surgical procedures. Weight loss and venous sinus stenting are a few therapies directed at the etiology.

Efficacy of dural venous sinus stenting in treating idiopathic intracranial hypertension with acute vision loss

INTRODUCTION

Dural venous sinus stenting (VSS) is an effective, durable treatment for patients with idiopathic intracranial hypertension (IIH) due to underlying venous sinus stenosis. However, the use of venous sinus stenting to treat IIH with acute vision loss has rarely been described.

METHODS

A retrospective chart analysis identified patients who received VSS for fulminant IIH, defined as acute (< 8 weeks) visual field loss to within the central 5° and/or a decrease in visual acuity to less than or equal to 20/50 in either eye in the presence of papilledema.

RESULTS

Ten patients were identified with average patient age of 31.0 years, and all except one were female. Mean body mass index was 41.2 kg/m². All patients presented with vision loss and some with headache and tinnitus. The average trans-stenotic gradient pre-stenting was 28.7 mmHg (range 9-62 mmHg). All patients had diminished or resolved venous gradients immediately following the procedure. At mean follow-up of 60.5 weeks, 100% had improvements in papilledema, 80.0% had subjective vision improvement, 55.6% had headache improvement and 87.5% had tinnitus improvement. 90.0% had stable or improved visual acuity in both eyes with a mean post-stenting Snellen acuity of 20/30 and an average gain of 3 lines Snellen acuity post-stenting (95% confidence intervals 0.1185-0.4286, p = 0.0018). Two patients (20.0%) required further surgical treatment (cerebrospinal shunting and/or stenting) after their first stenting procedure.

CONCLUSIONS

This series suggests that VSS is feasible in patients presenting with IIH and acute vision loss with a fairly low complication rate and satisfactory clinical outcomes.

A proposed framework for cerebral venous congestion

BACKGROUND

While venous congestion in the peripheral vasculature has been described and accepted, intracranial venous congestion remains poorly understood. The characteristics, pathophysiology, and management of cerebral venous stasis, venous hypertension and venous congestion remain controversial, and a unifying conceptual schema is absent. The cerebral venous and lymphatic systems are part of a complex and dynamic interaction between the intracranial compartments, with interplay between the parenchyma, veins, arteries, cerebrospinal fluid, and recently characterized lymphatic-like systems in the brain. Each component contributes towards intracranial pressure, occupying space within the fixed calvarial volume. This article proposes a framework to consider conditions resulting in brain and neck venous congestion, and seeks to expedite further study of cerebral venous diagnoses, mechanisms, symptomatology, and treatments.

METHODS

A multi-institution retrospective review was performed to identify unique patient cases, complemented with a published case series to assess a spectrum of disease states with components of venous congestion affecting the brain. These diseases were organized according to anatomical location and purported mechanisms. Outcomes of treatments were also analyzed. Illustrative cases were identified in the venous treatment databases of the authors.

CONCLUSION

This framework is the first clinically structured description of venous pathologies resulting in intracranial venous and cerebrospinal fluid hypertension. Our proposed system highlights unique clinical symptoms and features critical for appropriate diagnostic work-up and potential treatment. This novel schema allows clinicians effectively to approach cases of intracranial hypertension secondary to venous etiologies, and furthermore provides a framework by which researchers can better understand this developing area of cerebrovascular disease.

Papilledema: A review of etiology, pathophysiology, diagnosis, and management

Papilledema is optic nerve head edema secondary to raised intracranial pressure (ICP). It is distinct from other causes of optic disk edema in that visual function is usually normal in the acute phase. Papilledema is caused by transmission of elevated ICP to the subarachnoid space surrounding the optic nerve that hinders axoplasmic transport within ganglion cell axons. There is ongoing controversy as to whether axoplasmic flow stasis is produced by physical compression of axons or microvascular ischemia. The most common cause of papilledema, especially in patients under the age of 50, is idiopathic intracranial hypertension (IIH); however, conditions that decrease cerebrospinal fluid (CSF) outflow by either causing CSF derangements or mechanically blocking CSF outflow channels, and rarely conditions that increase CSF production, can be the culprit. When papilledema is suspected clinically, blood pressure should be measured, and pseudopapilledema should be ruled out. Magnetic resonance imaging of the brain and orbits with venography sequences is the preferred neuroimaging modality that should be performed next to look for indirect imaging signs of increased ICP and to rule out nonidiopathic causes. Lumbar puncture with measurement of opening pressure and evaluation of CSF composition should then be performed. In patients not in a typical demographic group for IIH, further investigations should be conducted to assess for underlying causes of increased ICP. Magnetic resonance imaging of the neck and spine, magnetic resonance angiography of the brain, computed tomography of the chest, complete blood count, and creatinine testing should be able to identify most secondary causes of intracranial hypertension. Treatment for patients with papilledema should be targeted toward the underlying etiology. Most patients with IIH respond to weight loss and oral acetazolamide. For patients with decreased central acuity and constricted visual fields at presentation, as well as patients who do not respond to treatment with acetazolamide, surgical treatments should be considered, with ventriculoperitoneal shunting being the typical procedure of choice.

Intracranial Access: Dural Venous Sinus Stenting: 2-Dimensional Operative Video

Cerebral venous sinus stenting has gained popularity in recent years as a safe and efficacious treatment of selected patients with idiopathic intracranial hypertension (IIH) and focal venous sinus stenosis.1-3 The main goal of treatment is to prevent visual loss, and often patients report resolution of headache and visual symptoms within 21 mo of mean follow-up.4-8 We present the case of a 57-yr-old woman with medically refractory IIH, bilateral sinus stenosis, and a mass lesion causing stenosis on the left. Venous angiogram with pressure monitoring was completed with the patient awake, which showed a significant pressure gradient on the right (19 mm Hg) and borderline gradient on the left (8 mm Hg). Options were reviewed and decision was made to proceed with the treatment of the right-sided stenosis with stenting and continue with the observation of the lesion on the left to prevent further visual deterioration. The patient consented for the procedure, and she tolerated the procedure well. Neurological exam remained at baseline, and she was discharged home on post-operative day #1. At 2 mo's follow-up, the patient reported improvement in headaches and remained intact neurologically.