Idiopathic Intracranial Hypertension. A Systematic Analysis of Transverse Sinus Stenting

Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Novel, braided, self-expandable stent designed for the treatment of pulsatile tinnitus caused by intracranial venous stenosis: first-in-human experience and long-term outcomes

BACKGROUND

Pulsatile tinnitus (PT) can be a disabling clinical condition, which may be caused by a sigmoid/transverse sinus stenosis (STSS). Intracranial venous stenting with off-label carotid or peripheral venous stents has been used successfully to treat this condition. We present the results of a cohort of patients presenting with PT treated with a novel, dedicated, braided stent for the endovascular treatment of STSS.

METHODS

Twelve patients presenting with PT and associated STSS were treated at our institution (December 2022-June 2023). All clinical and procedural variables were prospectively collected. We used the Tinnitus Function Index (TFI) and the Tinnitus Handicap Inventory (THI) scores to assess the impact of PT on quality of life before and after the treatment (mean follow-up: 10.3 months).

RESULTS

Twelve women (mean age: 44±16.5 years) presenting with PT and STSS were treated. Mean pretreatment TFI/THI scores were 78.8/77. The BosStent was successfully deployed in all patients. We experienced no intraprocedural/postoperative complications. Intra-stent angioplasty was performed in three cases. All patients reported a complete resolution of PT symptoms within 1 month and remained stable and PT-free at the last follow-up (mean posttreatment TFI/THI score: 7.1/5, p<0001).

CONCLUSIONS

The BosStent was successfully used in a cohort of patients with PT without any intraprocedural complications. All the patients experienced a complete resolution of PT symptoms after 1 month, which was stable during the follow-up period. Further studies with larger populations will be necessary to investigate the safety and effectiveness of this novel stent for the treatment of PT with STSS.

Endovascular stenting for cerebral venous sinus stenosis secondary to meningioma invasion

INTRODUCTION

Symptomatic intracranial hypertension (IH) due to venous outflow obstruction secondary to dural venous sinus (DVS) tumoral invasion affects up to 3% of intracranial meningioma patients. The literature regarding endovascular therapies of such patients is limited to a few case reports and a recent single-centre case series.

PURPOSE

We describe our single-centre experience of endovascular therapy in patients with clinically symptomatic IH secondary to DVS meningioma invasion.

METHODS

We performed a retrospective review of clinical and radiological data of all patients with refractory IH and meningiomas invading the DVS who were referred for possible DVS venoplasty and stenting. Seven endovascular procedures in six female patients were done. Presumed secondarily induced lateral transverse sinus stenosis was also stented in four patients as part of the primary intervention.

RESULTS

All patients experienced complete symptomatic resolution at 6-month follow-up. Five patients had no symptom recurrence over a mean follow-up period of 3.5 years. One patient with multiple meningiomas developed recurrent IH 2 years following stenting secondary to in-stent tumour re-invasion. This was re-stented with consequent 6 months post-retreatment symptomatic relief at the time of writing. No procedure-related complications occurred.

CONCLUSION

In the setting of DVS stenosis secondary to meningioma invasion, endovascular therapy is a safe and successful therapeutic option with promising mid-term results. The procedure should be considered in cases where complete surgical tumour resection is unlikely or carries a significant risk. If present, secondarily induced stenoses at the lateral ends of the transverse sinuses should also be considered for treatment.

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.

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.

Advances in the Endovascular Management of Cerebrovascular Disease

The field of endovascular neurosurgery has experienced remarkable progress over the last few decades. Endovascular treatments have continued to gain traction as the advancement of technology, technique, and procedural safety has allowed for the expansion of treatment indications of various cerebrovascular pathologies. Interventions such as the coiling of intracranial aneurysms, carotid artery stenting, mechanical thrombectomy in the setting of ischemic stroke, and endovascular embolization of arteriovenous malformations have all seen transformations in their safety and efficacy, expanding the scope of endovascularly treatable conditions and offering new hope to patients who may have otherwise not been candidates for surgical intervention. Despite this notable progress, challenges persist, including complications associated with device deployment and questions regarding long-term outcomes. This article explores the advancements in endovascular neurosurgical techniques, highlighting the impact on patient care, outcomes, and the evolution of traditional surgical methods.

CSF hyperdynamics in rats mimicking the obesity and androgen excess characteristic of patients with idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a syndrome exhibiting elevated intracranial pressure (ICP), visual disturbances, and severe headache. IIH primarily affects young obese women, though it can occur in individuals of any age, BMI, and sex. IIH is characterized by systemic metabolic dysregulation with a profile of increased androgen hormones. However, the contribution of obesity/hormonal perturbations to cerebrospinal fluid (CSF) dynamics remains unresolved.

METHODS

We employed obese female Zucker rats and adjuvant testosterone to reveal IIH causal drivers. ICP and CSF dynamics were determined with in vivo experimentation and magnetic resonance imaging, testosterone levels assessed with mass spectrometry, and choroid plexus function revealed with transcriptomics.

RESULTS

Obese rats had undisturbed CSF testosterone levels and no changes in ICP or CSF dynamics. Adjuvant testosterone treatment of obese rats elevated the CSF secretion rate, although with no effect on the ICP, due to elevated CSF drainage capacity of these rats.

CONCLUSIONS

Obesity in itself therefore does not suffice to recapitulate the IIH symptoms in rats, but modulation of CSF dynamics appears with adjuvant testosterone treatment, which mimics the androgen excess observed in female IIH patients. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH and could potentially serve as a future therapeutic target.

Supracerebellar infratentorial resection of a torcular lesion causing fulminant intracranial hypertension: illustrative case

BACKGROUND

Venous sinus stenosis has been implicated in intracranial hypertension and can lead to papilledema and blindness. The authors report the unique case of a cerebellar transtentorial lesion resulting in venous sinus stenosis in the torcula and bilateral transverse sinuses that underwent resection.

OBSERVATIONS

A 5-year-old male presented with subacute vision loss and bilateral papilledema. Imaging demonstrated a lesion causing mass effect on the torcula/transverse sinuses and findings of increased intracranial pressure (ICP). A lumbar puncture confirmed elevated pressure, and the patient underwent bilateral optic nerve sheath fenestration. Cerebral angiography and venous manometry showed elevated venous sinus pressures suggestive of venous hypertension. The patient underwent a craniotomy and supracerebellar/infratentorial approach. A stalk emanating from the cerebellum through the tentorium was identified and divided. Postoperative magnetic resonance imaging showed decreased lesion size and improved sinus patency. Papilledema resolved and other findings of elevated ICP improved. Pathology was consistent with atrophic cerebellar cortex. Serial imaging over 6 months demonstrated progressive decrease in the lesion with concurrent improvements in sinus patency.

LESSONS

Although uncommon, symptoms of intracranial hypertension in patients with venous sinus lesions should prompt additional workup ranging from dedicated venous imaging to assessments of ICP and venous manometry.

Association of post-intervention pressure gradient with symptom-free at 6 months in idiopathic intracranial hypertension with venous sinus stenosis treated by stenting

OBJECTIVE

This study aimed to identify the key factors that might affect the clinical outcome of patients with idiopathic intracranial hypertension (IIH) and Venous sinus stenting (VSS).

METHODS

We performed an analysis of a prospectively collected database of patients with IIH and VSS who underwent stenting. The trans-stenotic pressure gradient was measured before and after intervention. In additional, patients' baseline characteristics, procedure details and clinical outcomes at 6-month follow-up (including changes in headache, visual impairment, papilledema, etc.) were recorded. The effects of post-intervention pressure gradient on symptom-free at 6 months were explored using logistic regression analysis, generalized additive model and receiver operator characteristic (ROC) curve.

RESULTS

Of 101 patients included in this study, the median pressure gradient across stenosis decreased from 19 mmHg before intervention to 2 mmHg after intervention. At 6 months, symptom-free was observed in 58 cases (57.4%). Multivariable logistic analysis and generalized additive model showed that post-intervention pressure gradient (increased by 1 mmHg) was independently and linearly correlated with symptom-free (OR = 0.79, 95% CI = 0.67-0.94). Moreover, the post-intervention pressure gradient revealed moderate discrimination with an area under ROC curve of 0.68 (95% CI = 0.57-0.78). Similar associations were observed for the disappearance of headache and papilledema, but not for the visual recovery.

CONCLUSION

The post-intervention pressure gradient may be a valid and reliable predictor of 6-month clinical outcome in patients with IIH and VSS treated by stenting. Nevertheless, external validation with blinded outcome is still needed to confirm its performance before clinical application.

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.

Modelling idiopathic intracranial hypertension in rats: contributions of high fat diet and testosterone to intracranial pressure and cerebrospinal fluid production

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure (ICP), impaired vision, and headache. Most cases of IIH occur in obese women of childbearing age, though age, BMI, and female sex do not encompass all aspects of IIH pathophysiology. Systemic metabolic dysregulation has been identified in IIH with a profile of androgen excess. However, the mechanistic coupling between obesity/hormonal perturbations and cerebrospinal fluid dynamics remains unresolved.

METHODS

Female Wistar rats were either fed a high fat diet (HFD) for 21 weeks or exposed to adjuvant testosterone treatment for 28 days to recapitulate IIH causal drivers. Cerebrospinal fluid (CSF) and blood testosterone levels were determined with mass spectrometry, ICP and CSF dynamics with in vivo experimentation, and the choroid plexus function revealed with transcriptomics and ex vivo isotope-based flux assays.

RESULTS

HFD-fed rats presented with increased ICP (65%), which was accompanied by increased CSF outflow resistance (50%) without altered CSF secretion rate or choroid plexus gene expression. Chronic adjuvant testosterone treatment of lean rats caused elevated ICP (55%) and CSF secretion rate (85%), in association with increased activity of the choroid plexus Na⁺,K⁺,2Cl^- cotransporter, NKCC1.

CONCLUSIONS

HFD-induced ICP elevation in experimental rats occurred with decreased CSF drainage capacity. Adjuvant testosterone, mimicking the androgen excess observed in female IIH patients, elevated the CSF secretion rate and thus ICP. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH.

"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.

Surgical Fixation of Jugular Bulb Abnormalities Associated With Phelebectasia in Patients With Vascular Tinnitus

Internal jugular phlebectasia is a rare entity in which there is a fusiform dilatation of the internal jugular vein (IJV), usually presenting as a neck mass or tinnitus. The jugular bulb (JB) is an enlarged confluence connecting the sigmoid sinus and the IJV. It has been suggested that JB abnormality might also cause vertigo and pulsatile tinnitus. This prospective interventional study involved 15 patients with pulsatile tinnitus associated with internal jugular phlebectasia. Four patients presented with recurrent vertigo attacks. IJV diameter at rest ranged from 11 to 18 mm. Eight patients have had inner ear bone dehiscence, and 40% had high JB. All cases were treated by surgical fixation using a ringed polytetrafluoroethylene graft extending from the costoclavicular joint to the sigmoid sinus under fluoroscopic guidance. Tinnitus disappeared immediately postoperatively in all cases, followed by the disappearance of vertigo on the fourth day. Two cases reported thrombosis of the graft in the sixth and seventh months but maintained symptomatic improvement. Recurrence was reported in 2 cases while the grafts were patent. Surgical fixation by replacing the jugular vein and bulb with a synthetic graft may offer an excellent surgical option for relieving vascular tinnitus, especially in these young patients in whom endovascular therapy may not be a durable treatment.

Vascular remodeling in sheep implanted with endovascular neural interface

Objective.The aim of this work was to assess vascular remodeling after the placement of an endovascular neural interface (ENI) in the superior sagittal sinus (SSS) of sheep. We also assessed the efficacy of neural recording using an ENI.Approach.The study used histological analysis to assess the composition of the foreign body response. Micro-CT images were analyzed to assess the profiles of the foreign body response and create a model of a blood vessel. Computational fluid dynamic modeling was performed on a reconstructed blood vessel to evaluate the blood flow within the vessel. Recording of brain activity in sheep was used to evaluate efficacy of neural recordings.Main results.Histological analysis showed accumulated extracellular matrix material in and around the implanted ENI. The extracellular matrix contained numerous macrophages, foreign body giant cells, and new vascular channels lined by endothelium. Image analysis of CT slices demonstrated an uneven narrowing of the SSS lumen proportional to the stent material within the blood vessel. However, the foreign body response did not occlude blood flow. The ENI was able to record epileptiform spiking activity with distinct spike morphologies.Significance. This is the first study to show high-resolution tissue profiles, the histological response to an implanted ENI and blood flow dynamic modeling based on blood vessels implanted with an ENI. The results from this study can be used to guide surgical planning and future ENI designs; stent oversizing parameters to blood vessel diameter should be considered to minimize detrimental vascular remodeling.

Life-threatening idiopathic intracranial hypertension: the role of venous sinus stenting

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a clinical syndrome characterised by raised intracranial pressure with no discernible aetiology. It is relatively rare in children and its demographic features may differ from those of adults. The relationship between IIH and venous sinus stenosis (VSS) is well known. As VSS plays an important role in the pathophysiology, treatments have been developed aimed at improving venous blood outflow in refractory IIH. In the last two decades, venous sinus stenting has emerged as a treatment option in cases where stenosis is documented.

METHODS AND RESULTS

The scientific literature on paediatric cases of IIH and its treatment with venous sinus stenting was analysed. We present the case of a 6-year-old girl with a life-threatening presentation of IIH, who was treated with transverse sinus stenting and a lumboperitoneal shunt. We summarise the characteristic of paediatric stenting cases reported and review the literature focusing on the main aspects of venous sinus stenting.

CONCLUSION

VSS stenting could be a treatment tool for the acute presentation of IIH with severe symptoms and VSS plus an elevated trans-stenotic pressure gradient. However, in some cases, additional surgical treatment may be necessary.

Improved Ophthalmic Outcomes Following Venous Sinus Stenting in Idiopathic Intracranial Hypertension

Background

Ophthalmic outcomes following venous sinus stenting (VSS) in patients with idiopathic intracranial hypertension (IIH) are not well characterized.

Materials and Methods

A retrospective chart review was conducted on 86 consecutive patients with IIH who underwent venous sinus stenting at Mayo Clinic, Rochester, Minnesota and Stanford Medical Center, Palo Alto, California between May 2015 and October 2021. Patients with raised intracranial pressure from a non-IIH etiology were excluded. Clinical symptoms and neuro-ophthalmological data, including best corrected visual acuity (BCVA), visual field mean deviation, papilledema, and optical coherence tomography (OCT) peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell inner plexiform layer (GC-IPL), were analyzed. Baseline measurements before VSS and 3 months or more postoperatively were compared.

Results

Eighty-six subjects (82 female) were included in this study, with a median age of 33 (16-68) years and a median body mass index of 36.69 (22.30-62.00) kg/m2. 85/86 (98.8%) had attempted prior management with medication, and 12/86 (14%) had prior surgical management with optic nerve sheath fenestration, ventriculoperitoneal shunt, or bariatric surgery. Prior to VSS, 67/86 (77.9%) had papilledema, 85/86 (98.8%) had headaches, and 68/86 (79.1%) had pulsatile tinnitus. For patients with both pre- and post-VSS data available, the average papilledema grade was 1.76 (0-5) (n = 74) and the average OCT pRNFL was 186.34 (52.00-588.00) µm (n = 70), prior to VSS. A median of 4.0 (interquartile range 3.3-5.4) months after VSS, the average papilledema grade improved to 0.39 (0-2), p <0.001, and OCT pRNFL improved to 96.86 (47.00-168.00) µm, p <0.001. 28/86 (32.6%) patients no longer required medication for high intracranial pressure. 14/85 (16.5%) patients reported complete resolution of their headache and 55/71 (77.5%) reported improvement in headache quality. 40/68 (66.7%) reported complete resolution of pulsatile tinnitus. OCT GC-IPL, BCVA, and visual field mean deviation did not significantly change pre- vs post-VSS.

Conclusions

Our large consecutive case series corroborates smaller prior studies in demonstrating the overall efficacy of VSS for patients with IIH. We found both ophthalmic improvements, as demonstrated by the significantly reduced papilledema and pRNFL, and overall clinical symptom improvement.

Transverse Sinus Stenting Reverses Medically Refractory Idiopathic Intracranial Hypertension

Aim

To characterise the ophthalmic indications for, and ophthalmic efficacy of, transverse sinus stenting in adults with medically refractory idiopathic intracranial hypertension.

Methods

A retrospective cohort study was undertaken on a single-author database of 226 successive patients with confirmed idiopathic intracranial hypertension (IIH). A total of 32 patients were identified who received a transverse sinus stent for medically refractory disease. This which was defined as visual threat and/or intolerance of maximal medical therapy. Patients with medically refractory disease proceeded to stenting, if found to have a significant transverse sinus stenosis gradient at catheter venography. Visual threat was quantified via the degree of papilledema on optical coherence tomography of the retinal nerve fibre layer, and via the visual field mean deviation. CSF opening pressure at lumbar puncture and cerebral venous sinus pressure measurements from catheter venography were correlated with the ophthalmic data, noting also intolerance of maximal medical therapy. Complications of stenting were fully assessed.

Results

Medically refractory IIH was found in 18% of the total cohort of IIH patients. 90% of those with medically refractory disease had a significant transverse sinus stenosis pressure gradient, and 80% proceeded to stenting. The intervention eliminated papilledema in 96% of stented patients, and allowed 81% to cease acetazolamide. The need for a further procedure was low at 6%, and the safety profile was favourable.

Conclusions

Medically refractory disease in IIH is common (18%), and nearly always associated with a significant transverse sinus stenosis pressure gradient (90%). Endovascular stenting of the stenosis deserves wider uptake as a highly effective, safe, and usually definitive treatment. It safeguards vision by eliminating papilledema (96%), and allows most patients to cease acetazolamide (81%). By analogy with glaucoma, if acetazolamide is the prostaglandin of IIH and CSF diversion the emergency glaucoma filter, stenting is the minimally invasive glaucoma surgery.

Safety and efficacy comparison between OACs plus single antiplatelet and dual antiplatelet therapy in patients with cerebral venous sinus stenosis poststenting

Background and purpose

The present strategies regarding poststent management for cerebral venous sinus stenosis (CVSS) are inconsistent. Herein, we compared the safety and efficacy of oral anticoagulants (OACs) plus single antiplatelet therapy and dual antiplatelet therapy for CVSS poststenting.

Methods

A real-world observational study conducted from January 2009 through October 2019 enrolled patients who were diagnosed with CVSS and received stenting. Patients were divided into two groups according to the management they received poststenting. Group 1: OACs plus a single antiplatelet agent (clopidogrel 75 mg or aspirin 100 mg) and Group 2: dual antiplatelet therapy (clopidogrel 75 mg plus aspirin 100 mg). The safety (such as major or minor bleeding or venous thrombosis) and efficacy (the incidences of cerebral venous sinus restenosis, intrastent thrombosis, or stent displacement) of the two groups were compared.

Results

There were a total of 110 eligible patients in the final analysis, including 79 females and 31 males with a mean age of 43.42 ± 13.23 years. No major bleeding or venous thrombosis occurred in either of the two groups. Two minor bleeding events occurred in group 2 (one with subcutaneous bleeding points in both lower limbs, another with submucosal bleeding in the mouth), whereas no bleeding events occurred in Group 1. In addition, at the 1-year follow-up, one case of intraluminal restenosis and two cases of in-stent thrombi occurred in Group 2, while none occurred in Group 1. Neither stenosis at stent-adjacent segments nor stent migration was detected in either group during the 1-year following stent placement.

Conclusion

OACs plus single antiplatelet therapy and dual antiplatelet therapy alone are both safe and efficacious management strategies after CVSS stent placement. The former may have more advantages than the latter for inhibiting intrastent thrombosis. However, further research by larger, multicenter clinical trials is needed.

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.

Cerebrospinal fluid dynamics in idiopathic intracranial hypertension: a literature review and validation of contemporary findings

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a rare disease of unknown aetiology related possibly to disturbed cerebrospinal fluid (CSF) dynamics and characterised by elevated intracranial pressure (ICP) causing optic nerve atrophy if not timely treated. We studied CSF dynamics of the IIH patients based on the available literature and our well-defined cohort.

METHOD

A literature review was performed from PubMed between 1980 and 2020 in compliance with the PRISMA guideline. Our study includes 59 patients with clinical, demographical, neuro-ophthalmological, radiological, outcome data, and lumbar CSF pressure measurements for suspicion of IIH; 39 patients had verified IIH while 20 patients did not according to Friedman's criteria, hence referred to as symptomatic controls.

RESULTS

The literature review yielded 19 suitable studies; 452 IIH patients and 264 controls had undergone intraventricular or lumbar CSF pressure measurements. In our study, the mean CSF pressure, pulse amplitudes, power of respiratory waves (RESP), and the pressure constant (P0) were higher in IIH than symptomatic controls (p < 0.01). The mean CSF pressure was higher in IIH patients with psychiatric comorbidity than without (p < 0.05). In IIH patients without acetazolamide treatment, the RAP index and power of slow waves were also higher (p < 0.05). IIH patients with excess CSF around the optic nerves had lower relative pulse pressure coefficient (RPPC) and RESP than those without (p < 0.05).

CONCLUSIONS

Our literature review revealed increased CSF pressure, resistance to CSF outflow and sagittal sinus pressure (SSP) as key findings in IIH. Our study confirmed significantly higher lumbar CSF pressure and increased CSF pressure waves and RAP index in IIH when excluding patients with acetazolamide treatment. In overall, the findings reflect decreased craniospinal compliance and potentially depleted cerebral autoregulation resulting from the increased CSF pressure in IIH. The increased slow waves in patients without acetazolamide may indicate issues in autoregulation, while increased P0 could reflect the increased SSP.

State of the Art: Venous Causes of Pulsatile Tinnitus and Diagnostic Considerations Guiding Endovascular Therapy

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

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.

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 Unique Subset: Idiopathic Intracranial Hypertension Presenting as Spontaneous CSF Leak of the Anterior Skull Base

Introduction Spontaneous cerebrospinal fluid (CSF) leaks represent a unique clinical presentation of idiopathic intracranial hypertension (IIH), lacking classical features of IIH, including severe headaches, papilledema, and markedly elevated opening pressures.

Methods Following a single-institution retrospective review of patients undergoing spontaneous CSF leak repair, we performed a literature review of spontaneous CSF leak in patients previously undiagnosed with IIH, querying PubMed.

Results Our literature review yielded 26 studies, comprising 716 patients. Average age was 51 years with 80.8% female predominance, and average body mass index was 35.5. Presenting symptoms included headaches (32.5%), visual disturbances (4.2%), and a history of meningitis (15.3%). Papilledema occurred in 14.1%. An empty sella was present in 77.7%. Slit ventricles and venous sinus stenosis comprised 7.7 and 31.8%, respectively. CSF leak most commonly originated from the sphenoid sinus (41.1%), cribriform plate (25.4%), and ethmoid skull base (20.4%). Preoperative opening pressures were normal at 22.4 cm H2O and elevated postoperatively to 30.8 cm H2O. 19.1% of patients underwent shunt placement. CSF leak recurred after repair in 10.5% of patients, 78.6% involving the initial site. A total of 85.7% of these patients were managed with repeat surgical intervention, and 23.2% underwent a shunting procedure.

Conclusion Spontaneous CSF leaks represent a distinct variant of IIH, distinguished by decreased prevalence of headaches, lack of visual deficits, and normal opening pressures. Delayed measurement of opening pressure after leak repair may be helpful to diagnose IIH. Permanent CSF diversion may be indicated in patients exhibiting significantly elevated opening pressures postoperatively, refractory symptoms of IIH, or recurrent CSF leak.

Motor neuroprosthesis implanted with neurointerventional surgery improves capacity for activities of daily living tasks in severe paralysis: first in-human experience

BACKGROUND

Implantable brain-computer interfaces (BCIs), functioning as motor neuroprostheses, have the potential to restore voluntary motor impulses to control digital devices and improve functional independence in patients with severe paralysis due to brain, spinal cord, peripheral nerve or muscle dysfunction. However, reports to date have had limited clinical translation.

METHODS

Two participants with amyotrophic lateral sclerosis (ALS) underwent implant in a single-arm, open-label, prospective, early feasibility study. Using a minimally invasive neurointervention procedure, a novel endovascular Stentrode BCI was implanted in the superior sagittal sinus adjacent to primary motor cortex. The participants undertook machine-learning-assisted training to use wirelessly transmitted electrocorticography signal associated with attempted movements to control multiple mouse-click actions, including zoom and left-click. Used in combination with an eye-tracker for cursor navigation, participants achieved Windows 10 operating system control to conduct instrumental activities of daily living (IADL) tasks.

RESULTS

Unsupervised home use commenced from day 86 onwards for participant 1, and day 71 for participant 2. Participant 1 achieved a typing task average click selection accuracy of 92.63% (100.00%, 87.50%-100.00%) (trial mean (median, Q1-Q3)) at a rate of 13.81 (13.44, 10.96-16.09) correct characters per minute (CCPM) with predictive text disabled. Participant 2 achieved an average click selection accuracy of 93.18% (100.00%, 88.19%-100.00%) at 20.10 (17.73, 12.27-26.50) CCPM. Completion of IADL tasks including text messaging, online shopping and managing finances independently was demonstrated in both participants.

CONCLUSION

We describe the first-in-human experience of a minimally invasive, fully implanted, wireless, ambulatory motor neuroprosthesis using an endovascular stent-electrode array to transmit electrocorticography signals from the motor cortex for multiple command control of digital devices in two participants with flaccid upper limb paralysis.

Venous Sinus Stenosis Treatment in Pediatric Idiopathic Intracranial Hypertension: Illustrative Case and Literature Review

OBJECTIVE

To review the literature of venous sinus stenosis (VSS) treatment in children for idiopathic intracranial hypertension (IIH) and present our own institutional case.

METHODS

A literature review was conducted using the PubMed and MEDLINE databases up to June 2020. From 134 studies that were screened, 6 studies were chosen for analysis that included patients <18 years old, a diagnosis of IIH that fit Dandy diagnostic criteria, and angiogram obtained to assess for VSS. IIH symptoms experienced in the pediatric population and efficacy of venous sinus stenting were analyzed.

RESULTS

Eleven patients identified in the literature and 1 patient from our institution were included in the analysis. There was no statistically significant difference in pressure gradient response to stenting between male and female patients (P = 0.424) or patients with body mass index >90th percentile (P = 0.626). Larger decreases in pressure gradient after stent placement correlated with headache resolution (P = 0.0005). Patients who underwent unilateral stenting showed greater reduction in pressure gradient compared with patients who underwent bilateral stenting (average change 24 mm Hg vs. 5.75 mm Hg, P = 0.003).

CONCLUSIONS

Our analysis showed that VSS treatment has the potential to be a safe option for IIH in pediatric patients. VSS treatment has shown similar results to traditional cerebrospinal fluid diversion procedures, with a lower complication rate and need for revision. More studies should be conducted to analyze the long-term efficacy and safety of VSS treatment in pediatric patients with IIH.

Angiographic cerebral venous sinus calibers and drainage patterns in patients with normal intracranial pressure and idiopathic intracranial hypertension

BACKGROUND

Normative venous sinus diameters are not well established. This study seeks to compare two-dimensional digital subtraction cerebral angiographic (DSA) venous sinus calibers for patients with normal intracranial pressure (ICP) and with idiopathic intracranial hypertension (IIH).

METHODS

Patients who underwent diagnostic cerebral angiography from 2016 to 2020 were retrospectively identified. Two independent reviewers measured venous sinus calibers from anteroposterior (AP) and lateral carotid injection delayed venous phase in patients from two groups (group 1: patients with normal ICP; group 2: patients with IIH) after receiving training in a standardized measurement protocol, with measurements obtained from the superior sagittal sinus (SSS) through the sigmoid sinuses (SS).

RESULTS

97 patients from group 1 and 30 patients from group 2 were included. Interrater reliability was greater than 0.75 for all measured sites. Both groups had similar anatomical subtypes with most being right transverse sinus (TS) dominant or codominant. In group 1, men had significantly larger SSS on lateral view (p<0.001) and dominant TS calibers on AP view (p=0.02) compared with women. Both dominant TS measurements and SSS measurements (lateral plane) were significantly smaller among group 2 compared with group 1 (p<0.001 and 0.02, respectively). Patients with IIH had significantly larger dominant SS measurements (p=0.01). Bifid SSS anatomy was present in 9% of patients with mean caudal width 31 mm (range 19-49 mm).

CONCLUSIONS

This study is the first to provide two-dimensional DSA dural venous sinus calibers in patients with and without IIH and to compare anatomical drainage types and calibers among groups.

Extraluminal Sigmoid Sinus Angioplasty: A Pertinent Reconstructive Surgical Method Targeting Dural Sinus Hemodynamics to Resolve Pulsatile Tinnitus

OBJECTIVES

1) To provide information on the treatment of pulsatile tinnitus (PT) with transtemporal extraluminal sigmoid sinus angioplasty (ESSA); and 2) to discuss the current clinical management of PT.

STUDY DESIGN

This was a retrospective study.

SETTINGS

Multi-institutional tertiary university medical centers.

PATIENTS

Fifty-four PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction with or without sigmoid sinus wall anomalies or transverse sinus anomalies.

INTERVENTION

All patients underwent ESSA under local anesthesia.

MAIN OUTCOME MEASURES

Intraoperative discoveries and surgical resolution of PT, morphology, and computational fluid dynamics.

RESULTS

Fifty-three of the 54 (98%) patients experienced a significant reduction in, or complete resolution of, PT after ESSA. No major surgical complications occurred, except for one case where we observed a full collapse of the sinus wall. On average, this surgery reduced the cross-sectional area at the transverse-sigmoid junction by 61.5%. Our intraoperative discoveries suggest that sigmoid sinus wall anomalies may not be a definitive cause of PT. The transverse-sigmoid sinus system was significantly larger (in term of both cross-sectional area and volume) on the ipsilesional side compared with the contralesional side. Following ESSA, the vascular wall pressure and vortex flow at the transverse-sigmoid junction decreased considerably, and the flow velocity and wall shear stress increased significantly.

CONCLUSION

ESSA is a highly effective surgical technique for PT patients with transverse-sigmoid sinus enlargement and prominent transverse-sigmoid junction, regardless of whether they also have sigmoid sinus wall or transverse sinus anomalies. A large transverse-sigmoid system with prominent transverse-sigmoid junction is a predisposing factor for PT, and only by improving patients' intrasinus hemodynamics could PT be resolved efficiently. In cases without complete obstruction of venous return, ESSA is safe. No postoperative complications related to neurological disorders were observed.

Mid-term assessment of transverse sinus stent patency in 104 patients treated for intracranial hypertension secondary to dural sinus stenosis

BACKGROUND

Transverse sinus (TS) stenting is a valid treatment alternative for patients with intracranial hypertension caused by underlying bilateral TS stenoses. Its mid-term patency has, however, not been well documented.

OBJECTIVE

To assess the 6-month patency of TS stenting using subtracted CT venography (CTV).

METHODS

A retrospective analysis of a prospectively collected database of patients undergoing TS stenting was performed. The cohort was a single-center, single-operator series of 125 consecutive patients treated between 2008 and 2018. Mid-term follow-up 320-row detector CTV was available for review in 104 patients.

RESULTS

Follow-up CTV was obtained on average 6 months after stenting. Stents in all patients (100%) were patent. Subtracted reconstructions showed no intraluminal thrombus or neointimal hyperplasia. Native reconstructions confirmed the structural integrity of the stents. De novo stenosis proximal to the stent was noted in 10 cases (10%). A total of 10 patients (10%) received additional treatment due to recurrent symptoms. In univariate analysis, both high body mass index and stent size (>6 mm) were associated with development of de novo stenoses: OR 1.12 (95% CI 1.01 to 1.25, p=0.037) and OR 5.63 (95% CI 1.16 to 27.22, p=0.032), respectively. In multivariate analysis, only stent size (>6 mm) remained significant: OR 7.19 (95% CI 1.03 to 50.01, p=0.046).

CONCLUSION

TS stenting is an effective treatment for intracranial hypertension secondary to dural sinus stenosis in an appropriately selected patient population. A 320-row dynamic CTV is a high-quality non-invasive imaging method that can assess both the physical integrity of the stent and its patency. At mid-term follow-up, all imaged stents were patent. The occurrence of de novo stenoses proximal to the stent (10%) correlated with stent size (>6 mm).

An update on idiopathic intracranial hypertension in adults: a look at pathophysiology, diagnostic approach and management

Idiopathic intracranial hypertension is a neurological syndrome determined by a rise in intracranial pressure without a detectable cause. Course and prognosis may be changeable, requiring a multidisciplinary approach for its diagnosis and management. Although its precise pathogenesis is still unknown, many studies have been carried out to define the possible causal and associated factors, such as retinoids, steroid hormones, body mass index and recent weight gains, cytokines and adipokines levels. The clinical presentation can be variable including chronic headache, disturbance of vision, diplopia and tinnitus. Even if papilloedema is considered the most specific sign, it could not be observed in more than 5% of patients during the evaluation of the fundus oculi. Neuroradiological signs acquire greater importance in patients who do not present papilloedema and may suggest the diagnosis of idiopathic intracranial hypertension. Other assessments can be useful in the diagnostic process, such as optical coherence tomography, visual evoked potentials, ocular ultrasonography and fundus fluorescein angiography and autofluorescence. Nonetheless, cerebrospinal fluid pressure measurement is required to establish a definite diagnosis. Management may be different, since surgical procedures or lumbar punctures are often required when symptoms develop rapidly leading to a loss of visual function. Apart from these cases, patients can be treated with a pharmacological approach and low-calorie diet, but they also need to be monitored over time since relapses years later are not uncommon.

Endovascular Neuromodulation: Safety Profile and Future Directions

Endovascular neuromodulation is an emerging technology that represents a synthesis between interventional neurology and neural engineering. The prototypical endovascular neural interface is the Stentrode^TM, a stent-electrode array which can be implanted into the superior sagittal sinus via percutaneous catheter venography, and transmits signals through a transvenous lead to a receiver located subcutaneously in the chest. Whilst the Stentrode^TM has been conceptually validated in ovine models, questions remain about the long term viability and safety of this device in human recipients. Although technical precedence for venous sinus stenting already exists in the setting of idiopathic intracranial hypertension, long term implantation of a lead within the intracranial veins has never been previously achieved. Contrastingly, transvenous leads have been successfully employed for decades in the setting of implantable cardiac pacemakers and defibrillators. In the current absence of human data on the Stentrode^TM, the literature on these structurally comparable devices provides valuable lessons that can be translated to the setting of endovascular neuromodulation. This review will explore this literature in order to understand the potential risks of the Stentrode^TM and define avenues where further research and development are necessary in order to optimize this device for human application.

Endovascular Stenting Following Stereotactic Radiosurgery for Meningioma Involving the Superior Sagittal Sinus

Objective

Surgical removal of meningiomas that have partially invaded the superior sagittal sinus (SSS) is difficult because it requires reconstruction of the SSS, which can lead to SSS occlusion and venous infarction. The present report details the case of an SSS-involved meningioma treated by stereotactic radiosurgery (SRS) and stenting.

Case Presentation

A 60-year-old woman was admitted to the hospital with blurred vision and papilledema. Lumbar puncture showed markedly increased intracranial pressure (ICP; 340 mm H2O). Gadolinium-enhanced T1-weighted imaging revealed a 1-cm meningioma located mainly in the SSS. Digital subtraction angiography revealed severe stenosis, at the posterior part of the SSS, and no collateral flow. The ICP was considered a result of the stenosis caused by the meningioma. A combined therapy comprising transarterial embolization (for tumor growth suppression), endovascular stenting of the SSS (for intracranial hypertension improvement), and SRS (for tumor control) was planned. SRS was performed first to avoid interference by the metal artifacts caused by the stent. After placement of a self-expanding stent, partial recanalization was achieved. Two months after stenting, SSS stenosis improved and MRI results showed shrinkage of the meningioma. Thirty months after the treatment, no tumor recurrence was observed.

Conclusion

The treatment strategy of SRS followed by stenting was successful for a SSS-involved meningioma. ICP and a pressure gradient between the pre- and post-stenotic segments should be considered indications for stenting.

Changes in mean arterial pressure and end-tidal carbon dioxide content affect venous sinus pressures in patients with idiopathic intracranial hypertension: a randomized study

Introduction

Little is known about how changes in physiologic parameters affect venous sinus pressure measurements, waveforms, or gradients associated with sinus stenosis.

Objective

To evaluate the effect of changes in cardiovascular and respiratory physiologic parameters on venous sinus pressure and caliber measurements in patients with idiopathic intracranial hypertension (IIH) undergoing venous sinus stenting.

Methods

In a prospective, randomized pilot study, eight patients with IIH undergoing venous sinus stenting were randomized to one of two groups. Under general anesthesia, patients underwent venous manometry and waveform recordings twice in succession based on assigned physiologic groups immediately before stenting. The mean arterial pressure (MAP) group maintained normocapnia but modified MAPs in two arms to control for temporal confounding: group A1 (MAP 60-80 mm Hg then 100–110 mm Hg) and group A2 (MAP 100-110 mm Hg then 60–80 mm Hg). The end-tidal carbon dioxide (EtCO2) group maintained a high-normal MAP similar to standard neuroanesthesia goals and modified EtCO2: group B1 (EtCO2 24–26 mm Hg then 38–40 mm Hg) and B2 (EtCO2 28–40 mm Hg then 24–26 mm Hg).

Results

In group A, superior sagittal sinus (SSS) pressures (ranging from 8 to 76 mm Hg) and trans-stenotic pressure gradients (TSPGs) (ranging from 2 to 67 mm Hg) were seen at MAP of 100–110 mm Hg compared with SSS pressures (4–38 mm Hg) and TSPGs (3–31 mm Hg) at 60–80 mm Hg. In group B, SSS pressures and TSPGs were considerably higher at EtCO2 levels of 38–40 mm Hg (15–57 mm Hg and 3–44 mm Hg, respectively) than at 24–26 mm Hg (8–26 mm Hg and 1–8 mm Hg, respectively).

Conclusions

Despite the small sample size, this pilot study demonstrates a dramatic effect of both MAP and EtCO2 on venous sinus pressures obtained during venography. These findings underscore the importance of maintaining normal physiologic cardiovascular and respiratory parameters during venous sinus manometry.

Safety and Clinical Outcomes after Transverse Venous Sinus Stenting for Treatment of Refractory Idiopathic Intracranial Hypertension: Single Center Experience

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a syndrome of elevated intracranial pressure of unknown etiology. Unilateral or bilateral transverse sinus (TS) or transverse-sigmoid junction stenosis is present in about 30%-93% of these patients. There is an ongoing debate on whether venous sinus stenosis is the cause of IIH or a result of it. The subset of IIH patients who continue to have clinical deterioration despite maximum medical therapy is termed as "refractory IIH." Traditionally, cerebrospinal fluid diversion surgeries (ventriculoperitoneal shunt and lumboperitoneal shunt) and optic nerve sheath fenestration (ONSF) were the mainstays of treatment for refractory IIH. In the last decade, venous sinus stenting (VSS) has emerged as a safe and effective option for treating refractory IIH patients with venous sinus stenosis. Through this study, we want to share our experience with venous stenting in refractory IIH patients with venous sinus stenosis associated with a significant pressure gradient (≥10 mm Hg).

METHODS

Retrospective chart review of all the patients diagnosed with refractory IIH who underwent VSS or angioplasty at our comprehensive stroke center from November 2016 to March 2019.

RESULTS

A total of seven refractory IIH patients underwent VSS or angioplasty within the specified period. The mean age was 39 years. Eighty-five percent of the patients were women (n = 6). The mean body mass index (BMI) was 37 kg/m². Headache was the most common symptom (85%, n = 6) followed by transient visual obscurations (71%, n = 5) and pulsatile tinnitus (57%; n = 4). All patients had papilledema. Fifty-seven percent of patients (n = 4) had impaired visual field. Mean lumbar opening pressure was 40.6 cm H₂O (SD = 9.66; 95% CI = 33.5-47.7). All patients were on maximum doses of acetazolamide ± furosemide. Six patients (85%) had dominant right transverse-sigmoid sinus. Fifty-seven percent of the patients had severe right transverse ± sigmoid sinus stenosis (n = 4) and the rest (43%) had bilateral TS stenosis (n = 3). Prestenting mean trans-stenosis pressure gradient was 18 mm Hg (SD = 6.16; 95% CI = 13.43-22.57). Six patients (85%) were treated with TS stenting and one (15%) with only angioplasty. Poststenting mean trans-stenosis pressure gradient was 4.8 mm Hg (SD = 6.6; 95% CI = -0.1-9.7). All patients were able to come off their medications with significant improvement in neurological and ophthalmological signs and symptoms. No procedure-related complications occurred.

CONCLUSION

TS stenting ± angioplasty is a safe and effective means of treating refractory IIH with venous sinus stenosis associated with a significant pressure gradient (≥10 mm Hg).

Contemporary management of the pseudotumor cerebri syndrome

Introduction: Diagnosis and appropriate management of patients with the pseudotumor cerebri syndrome are imperative to prevent or minimize permanent visual loss and headache-related disability. Areas covered: Steps in management, including making the correct diagnosis, techniques to assess the patient's visual status, medical treatment of intracranial hypertension and the associated headaches, weight management strategies, surgical treatments and stenting are reviewed incorporating the most recent medical evidence. Expert opinion: As the pathogenesis of the pseudotumor cerebri syndrome is still unknown, many of the currently employed management strategies incorporate a 'plumbing approach' to decrease cerebrospinal fluid (CSF) pressure. The Idiopathic Intracranial Hypertension Trial (IIHTT) taught us that the disorder markedly affects visual and overall quality of life, and that reducing pressure alone is not enough to make patients well, even those considered to have 'mild' vision loss. Other than the IIHTT, the evidence supporting the use of various treatments is meager. The course of the disorder can be unpredictable, and the clinician(s) managing these patients are often uncertain about which treatments to employ. Moreover, the desired modalities and specialists are not universally available in all locations. An individualized and detailed approach to the various manifestations and nuances of the disorder is essential.

A descriptive study of venous sinus pressures and gradients in patients with idiopathic intracranial hypertension

Objective

To determine the relationship between normal physiologic and pathologic venous sinus pressures in patients with idiopathic intracranial hypertension (IIH), which is poorly understood.

Methods

Retrospective analysis was performed to identify patients with medically refractory IIH who were evaluated by angiography and retrograde venography with venous manometry. Patients were further subdivided into groups based on anatomic factors.

Results

104 patients met inclusion criteria for the study. In the absence of non-invasive venographic screening, 58% of patients in this series were found to have pressure gradients of ≥8 mm Hg; 93% were located near the transverse-sigmoid sinus junction. Opening pressure (OP) is strongly predictive of superior sagittal sinus (SSS) pressures (p<0.001) and also of the presence of a pressure gradient ≥8 mm Hg (p<0.001). Twenty-three percent of patients with an OP <25 had a pressure gradient ≥8 mm Hg compared with 77% of patients with an OP ≥35. Analysis of patients with OP ≤20 suggests that SSS pressures in patients without IIH should be less than 16–18 mm Hg with total cranial gradients <5 mm Hg. Across all patients, a pressure decrement of approximately 1 mm Hg occurs with progressively more caudal transition across anatomic points of measurement.

Conclusions

This study describes intracranial and extracranial venous pressure measurements and gradients in different subgroups of patients with IIH. OP is highly predictive of intracranial venous pressures and significant venous pressure gradients.

Percutaneous endovascular biopsy in the diagnosis of venous sinus lesions: technical note

Intracranial hypertension (IH) may be misdiagnosed owing to the lack of typical imaging features and pathological confirmation of the sinus lesions. The authors report the use of percutaneous endovascular biopsy (PEB) for the diagnosis of IH in patients with venous sinus lesions. A total of 9 patients (age 46 ± 9 years) underwent PEB between June 2016 and August 2017. All patients underwent lumbar puncture and contrast-enhanced MRI before the procedure. PEB was technically successful in 6 patients. No intra- or postprocedural complications occurred. The confirmed lesions were meningioma in 2 patients and fibrous thrombus in 4 patients. All patients received individualized treatment. PEB of venous sinus lesions is a safe and efficient method to establish an early diagnosis and appropriate treatment in patients with IH.

Pattern and severity of transverse sinus stenosis in patients with pulsatile tinnitus associated with sigmoid sinus wall anomalies

OBJECTIVE

Describe the location and severity of transverse sinus stenosis (TSS) in a consecutive series of patients with intraoperatively confirmed sigmoid sinus wall abnormalities (SSWA).

METHODS

A retrospective review of imaging studies from patients undergoing sinus wall reconstruction for pulsatile tinnitus associated with SSWA "was performed." Qualitative and quantitative analyses of the TSS, including the side, type, location, extent, and severity, were performed and compared with normal controls and historical controls with idiopathic intracranial hypertension (IIH).

RESULTS

Twenty-six of 36 subjects had adequate imaging data. The majority of subjects had some degree of bilateral TSS, and the majority of stenoses involved the distal transverse sinus. Subjects with diverticulum were significantly more likely than those with dehiscence to have ipsilateral distal TSS (16 of 16 vs. 4 of 10, P = 0.009). The mean minimum transverse sinus diameter, stenosis severity grade, and overall posterior venous sinus outflow were significantly worse in the subjects as compared to normal controls (P = 0.002), although not as severe as the comparable values in historical controls with IIH (P < 0.003).

CONCLUSION

Subjects with SSWA have a high incidence of TSS, with patterns differing between those with dehiscence and diverticulum. Severity of TSS and overall posterior fossa venous outflow are worse as compared to normal controls but not as severe as in subjects with IIH. These findings have implications for the pathophysiology and management of SSWA.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1028-1033, 2020.

Venous Manometry as an Adjunct for Diagnosis and Multimodal Management of Intracranial Hypertension due to Meningioma Compressing Sigmoid Sinus

Intracranial venous hypertension is a rare presentation of meningiomas in the transverse-sigmoid sinus region. We describe a case of a young patient presenting with intracranial hypertension due to a meningioma causing compression of the dominant sigmoid sinus. We were able to document the cerebral venous pressure gradient across the lesion confirming our hypothesis that compression of the sigmoid sinus from the meningioma was the cause of intracranial hypertension. The patient is a 17-year-old male who presented with intracranial hypertension due to meningioma at the right dominant sigmoid sinus, which was treated by a Simpson grade IV surgical resection followed by stereotactic radiosurgery. Following treatment, his papilledema resolved and he remains symptom-free at 18 months. In conclusion, venous manometry is a useful adjunct to diagnose intracranial hypertension in non-idiopathic causes of intracranial hypertension. A multimodal management approach of intracranial hypertension due to outflow obstruction from the dominant sinus led to an excellent recovery on follow up.

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 stenting for idiopathic intracranial hypertension with venous sinus stenosis

OBJECTIVES

Idiopathic intracranial hypertension (IIH) is characterized by elevated intracranial pressure of unknown etiology and venous sinus stenting may be an optional treatment. We aimed to evaluate the effects of venous sinus stenting on visual function, intracranial pressure, and trans-stenotic pressure gradient of the patients with IIH and to determine effects of baseline BMI or weight changes on subjective vision outcome and intracranial pressure.

METHODS

From July 2009 to Aug 2016, 88 eligible patients with IIH and venous sinus stenosis who underwent stenting were retrospectively studied.

RESULTS

In this study, 67 women and 21 men were included with an average age of 39.01 (18-60) years. The average BMI was 26.75 kg/m2 . Here, 66 (75.9%) patients had papilledema, 39 had impaired vision before stenting; 57 patients were followed-up, 48 (84.2%) showed significant subjective improvement or recovery in visual acuity, 4 (7.0%) patients reported no significant change in visual functions, and 5 (8.8%) suffered permanent vision loss. The cerebrospinal fluid opening pressure and trans-stenotic pressure gradient were significantly decreased postoperatively. Baseline BMI was associated with pre-and postoperative trans-stenotic pressure gradients, as well as changes in cerebrospinal fluid opening pressure. However, baseline BMI and body weight changes during follow-up were not necessarily associated with subjective visual outcomes after stenting. Stenting efficacy was limited in patients with severe preoperative optic symptoms.

CONCLUSIONS

Venous sinus stenting represented an effective treatment for resolving visual dysfunction and intracranial pressure associated with venous sinus stenosis. BMI seemed to be associated with intracranial pressure but not subjective visual outcomes after stenting.

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.

Removing the need for invasive brain surgery: the potential of stent electrodes

Over the last decade, significant advances in brain–machine interfaces have demonstrated that people with paralysis can control assistive technology such as computers, wheelchairs and bionic arms with their minds. However, due to the invasive surgery required to access the brain and implant electrodes, to date, no device has received commercial US FDA approval, and consequently there is no existing solution to return independence and mobility for the hundreds-of-millions of people paralyzed by stroke, spinal cord injury and motor neuron disease. But there is hope. We have developed a minimally invasive brain–machine interface that can access the brain using cortical vessels which mitigates the risks associated with open brain surgery.

European headache federation guideline on idiopathic intracranial hypertension

Background

Idiopathic Intracranial Hypertension (IIH) is characterized by an elevation of intracranial pressure (ICP no identifiable cause. The aetiology remains largely unknown, however observations made in a number of recent clinical studies are increasing the understanding of the disease and now provide the basis for evidence-based treatment strategies.

Methods

The Embase, CDSR, CENTRAL, DARE and MEDLINE databases were searched up to 1st June 2018. We analyzed randomized controlled trials and systematic reviews that investigate IIH.

Results

Diagnostic uncertainty, headache morbidity and visual loss are among the highest concerns of clinicians and patients in this disease area. Research in this field is infrequent due to the rarity of the disease and the lack of understanding of the underlying pathology.

Conclusions

This European Headache Federation consensus paper provides evidence-based recommendations and practical advice on the investigation and management of IIH.

Electronic supplementary material

The online version of this article (10.1186/s10194-018-0919-2) contains supplementary material, which is available to authorized users.

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.

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.