Characterisation and Visual Outcomes of Fulminant Idiopathic Intracranial Hypertension: A Narrative Review.

Fulminant idiopathic intracranial hypertension (IIH) is a rapid vision-degrading presentation of IIH with limited published studies. This study composed a narrative review of fulminant IIH with the aim of better characterising fulminant IIH presentation and visual outcomes. SCOPUS and PubMed were searched for papers referencing IIH, benign intracranial hypertension, or pseudotumour cerebri. Abstracts were screened for rapid degradation in vision. All studies were required to meet both the modified Dandy and fulminant IIH criteria. Thirty-six studies met the inclusion criteria. Demographics, treatments, and visual outcome data were collected. Case studies made up 69% of the studies and 31% were case series. In total, 72 patients with fulminant IIH were reported, of which 23.6% were paediatric and 96% were female. Surgical intervention occurred in 85% of patients. Anaemia was present in 11% of patients and 85.7% of paediatric patients had a sixth cranial nerve palsy. In conclusion, we propose the following practice guidelines to assist in diagnosing and treating fulminant IIH patients: 1) patients who present with optic disc oedema require urgent visual field testing to evaluate for vision loss; 2) a paediatric patient presenting with a sixth cranial nerve palsy should have a comprehensive eye examination; 3) fulminant IIH can occur in patients with a normal body mass index; and 4) anaemia should be tested for in the setting of fulminant IIH. As little is known about the optimal treatment mechanisms for this presentation, multi-institutional and international collaborations will be a critical step for future research.

Spinal cord motion and CSF flow in the cervical spine of 70 healthy participants.

Pulsatile spinal cord and CSF velocities related to the cardiac cycle can be depicted by phase-contrast MRI. Among patients with spontaneous intracranial hypotension, we have recently described relevant differences compared with healthy controls in segment C2/C3. The method might be a promising tool to solve clinical and diagnostic ambiguities. Therefore, it is important to understand the physiological range and the effects of clinical and anatomical parameters in healthy volunteers. Within a prospective study, 3D T2 -weighted MRI for spinal canal anatomy and cardiac-gated phase-contrast MRI adapted to CSF flow and spinal cord motion for time-resolved velocity data and derivatives were performed in 70 participants (age 20-79 years) in segments C2/C3 and C5/C6. Correlations were analyzed by multiple linear regression models; p < 0.01 was required to assume a significant impact of clinical or anatomical data quantified by the regression coefficient B. Data showed that in C2/C3, the CSF and spinal cord craniocaudal velocity ranges were 4.5 ± 0.9 and 0.55 ± 0.15 cm/s; the total displacements were 1.1 ± 0.3 and 0.07 ± 0.02 cm, respectively. The craniocaudal range of the CSF flow rate was 8.6 ± 2.4 mL/s; the CSF stroke volume was 2.1 ± 0.7 mL. In C5/C5, physiological narrowing of the spinal canal caused higher CSF velocity ranges and lower stroke volume (C5/C6 B = +1.64 cm/s, p < 0.001; B = -0.4 mL, p = 0.002, respectively). Aging correlated to lower spinal cord motion (e.g., B = -0.01 cm per 10 years of aging, p < 0.001). Increased diastolic blood pressure was associated with lower spinal cord motion and CSF flow parameters (e.g., C2/C3 CSF stroke volume B = -0.3 mL per 10 mmHg, p < 0.001). Males showed higher CSF flow and spinal cord motion (e.g., CSF stroke volume B = +0.5 mL, p < 0.001; total displacement spinal cord B = +0.016 cm, p = 0.002). We therefore propose to stratify data for age and sex and to adjust for diastolic blood pressure and segmental narrowing in future clinical studies.

B-mode transorbital ultrasonography for the diagnosis of idiopathic intracranial hypertension: an updated systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to evaluate the role of B-mode transorbital ultrasonography (TOS) for the diagnosis of idiopathic intracranial hypertension (IIH) in adults. METHODS: MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) (1966-May 2022) were searched to identify studies reporting ultrasonographic data about the optic nerve sheath diameter (ONSD) and optic disc elevation (ODE) in adults with IIH compared to subjects without IIH. The quality of the included studies was evaluated by the Newcastle-Ottawa Quality. RESULTS: Fifteen studies were included (total of 439 patients). The values of ODE ranged from 0.6 to 1.3 mm in patients with IIH. The values of ONSD ranged from 4.7 to 6.8 mm in IIH patients and from 3.9 to 5.7 mm in controls. In IIH patients, the ONSD was significantly higher compared to controls (standardized mean difference: 2.5 mm, 95% confidence interval (CI): 1.6-3.4 mm). Nine studies provided data about the presence of papilledema and the pooled prevalence was 95% (95% CI, 92-97%). CONCLUSIONS: In adults, the thickness of ONSD and the entity of ODE were significantly associated with IIH. B-mode TOS enables to noninvasively detect increased ICP and should be performed, potentially routinely, in any patient with suspected IIH.

The clinical findings to notice mild elevation of intracranial pressure in an otology clinic.

Mildly elevated intracranial pressure appears to be a distinct pathology separate from idiopathic increased intracranial pressure and migraine. Many patients present with head fullness-pressure and dizziness, which is often suggestive of a clinical diagnosis of vestibular migraine. These patients may additionally have episodic vertigo as seen in endolymphatic hydrops and positional vertigo in addition to feeling dizzy. In most cases, hearing is normal. A long duration of the condition or a presence of associated ear pathologies, i.e., dehiscence, fistula, hypermobile footplate, or history of chronic ear infections can add hearing loss to clinical presentations. Low-pitch pulsatile tinnitus, when present, is an important symptom. The neuroimaging findings such as partially empty sella, blockage of the dural venous sinus or sigmoid sinus wall defects are frequently observed. The condition is diagnosed by measuring the lumbar puncture opening pressure. Typically, patients have normal cerebrospinal fluid chemistry and microscopy. Lowering the pressure during the lumbar puncture will resolve the patient's symptoms temporarily. Medical therapy is typically successful using carbonic anhydrase inhibitors and corrections of medical disorders that may be contributing to the increased pressure. A few require shunting or stenting procedures. In this review article, we define the condition in detail with illustrative cases that we collected from our practices.

Can we preserve the necrotic testis caused by incarcerated inguinal hernia in infants under 3 months?

PURPOSE: This study aims to investigate whether necrotic testis resulting from incarcerated inguinal hernias can be preserved in infants under 3 months old. METHODS: A retrospective analysis was conducted on data collected from infants under 3 months old who had necrotic testis caused by incarcerated inguinal hernias between 2016 and 2020. They were divided into two groups: the orchiectomy group and the testicular preservation group. The control group consisted of normal male children of the same age. Data regarding bilateral testicular volume, dihydrotestosterone, inhibin B, and antisperm antibodies were collected. RESULTS: The study included 42 cases, with 18 patients being followed up for 6-54 months after the operation. In the testicular preservation group, 2 children did not experience testicular atrophy. There was no significant difference in the volume of the contralateral testes between the testicular preservation group and the control group; however, both groups had smaller testicular volumes compared to the orchiectomy group. There was no significant difference in the levels of inhibin B between the testicular preservation group and the orchiectomy group, although both were lower than the control group. Furthermore, no significant difference was observed in the levels of dihydrotestosterone and the positivity rate of antisperm antibodies among the three groups. CONCLUSION: Preserving the necrotic testis may allow it to survive without impacting the contralateral testis. Therefore, a more conservative approach should be considered for orchiectomy when dealing with testicular necrosis caused by incarcerated inguinal hernias in infants.

The Link of mRNA and rRNA Transcription by PUF60/FIR through TFIIH/P62 as a Novel Therapeutic Target for Cancer.

The interaction between mRNA and ribosomal RNA (rRNA) transcription in cancer remains unclear. RNAP I and II possess a common N-terminal tail (NTT), RNA polymerase subunit RPB6, which interacts with P62 of transcription factor (TF) IIH, and is a common target for the link between mRNA and rRNA transcription. The mRNAs and rRNAs affected by FUBP1-interacting repressor (FIR) were assessed via RNA sequencing and qRT-PCR analysis. An FIR, a c-myc transcriptional repressor, and its splicing form FIRΔexon2 were examined to interact with P62. Protein interaction was investigated via isothermal titration calorimetry measurements. FIR was found to contain a highly conserved region homologous to RPB6 that interacts with P62. FIRΔexon2 competed with FIR for P62 binding and coactivated transcription of mRNAs and rRNAs. Low-molecular-weight chemical compounds that bind to FIR and FIRΔexon2 were screened for cancer treatment. A low-molecular-weight chemical, BK697, which interacts with FIRΔexon2, inhibited tumor cell growth with rRNA suppression. In this study, a novel coactivation pathway for cancer-related mRNA and rRNA transcription through TFIIH/P62 by FIRΔexon2 was proposed. Direct evidence in X-ray crystallography is required in further studies to show the conformational difference between FIR and FIRΔexon2 that affects the P62-RBP6 interaction.

Co-morbid Polycystic Ovarian Syndrome with Idiopathic Intracranial Hypertension.

The link between polycystic ovarian syndrome (PCOS) and idiopathic intracranial hypertension (IIH) has long been debated. Historically, there is a wide range of reported occurrence of both conditions, being between 15% and 64%. Both conditions share a common phenotype. The awareness that in a new large data study that there is a 1.5-fold increased prevalence of diagnosed PCOS in participants with IIH as compared to the controls is important. Assessment for the potential of co-morbid PCOS in women with IIH is important as this may enable optimisation of weight and fertility management.

TRAPPC11-related muscular dystrophy with hypoglycosylation of alpha-dystroglycan in skeletal muscle and brain.

AIMS: TRAPPC11, a subunit of the transport protein particle (TRAPP) complex, is important for complex integrity and anterograde membrane transport from the endoplasmic reticulum (ER) to the ER-Golgi intermediate compartment. Several individuals with TRAPPC11 mutations have been reported with muscle weakness and other features including brain, liver, skeletal and eye involvement. A detailed analysis of brain and muscle pathology will further our understanding of the presentation and aetiology of TRAPPC11 disease. METHODS: We describe five cases of early-onset TRAPPC11-related muscular dystrophy with a systematic review of muscle pathology in all five individuals, post-mortem brain pathology findings in one and membrane trafficking assays in another. RESULTS: All affected individuals presented in infancy with muscle weakness, motor delay and elevated serum creatine kinase (CK). Additional features included cataracts, liver disease, intellectual disability, cardiomyopathy, movement disorder and structural brain abnormalities. Muscle pathology in all five revealed dystrophic changes, universal hypoglycosylation of alpha-dystroglycan and variably reduced dystrophin-associated complex proteins. Membrane trafficking assays showed defective Golgi trafficking in one individual. Neuropathological examination of one individual revealed cerebellar atrophy, granule cell hypoplasia, Purkinje cell (PC) loss, degeneration and dendrite dystrophy, reduced alpha-dystroglycan (IIH6) expression in PC and dentate neurones and absence of neuronal migration defects. CONCLUSIONS: This report suggests that recessive mutations in TRAPPC11 are linked to muscular dystrophies with hypoglycosylation of alpha-dystroglycan. The structural cerebellar involvement that we document for the first time resembles the neuropathology reported in N-linked congenital disorders of glycosylation (CDG) such as PMM2-CDG, suggesting defects in multiple glycosylation pathways in this condition.

Features of Idiopathic Intracranial Hypertension on MRI With MR Elastography: Prospective Comparison With Control Individuals and Assessment of Postintervention Changes.

BACKGROUND. Understanding of dynamic changes of MRI findings in response to intracranial pressure (ICP) changes in idiopathic intracranial hypertension (IIH) is limited. Brain stiffness, as assessed by MR elastography (MRE), may reflect changes in ICP. OBJECTIVE. The purpose of this study was to compare pituitary height, ventricular size, and brain stiffness between patients with IIH and control individuals and to evaluate for changes in these findings in patients with IIH after interventions to reduce ICP. METHODS. This prospective study included 30 patients (28 women, two men; median age, 29.9 years) with IIH and papilledema and 21 control individuals (21 women, 0 men; median age, 29.1 years), recruited from January 2017 to July 2019. All participants underwent 3-T brain MRI with MRE; patients with IIH underwent additional MRI examinations with MRE after acute intervention (lumbar puncture with normal closing pressure; n = 11) and/or chronic intervention (medical management or venous sinus stenting with resolution or substantial reduction in papilledema; n = 12). Pituitary height was measured on sagittal MP-RAGE images. Ventricular volumes were estimated using unified segmentation, and postintervention changes were assessed by tensor-based morphometry. Stiffness pattern score and regional stiffness values were estimated from MRE. RESULTS. In patients with IIH, median pituitary height was smaller than in control individuals (3.1 vs 4.9 mm, p < .001) and was increased after chronic (4.0 mm, p = .05), but not acute (2.3 mm, p = .50), intervention. Ventricular volume was not different between patients with IIH and control individuals (p = .33) and did not change after acute (p = .83) or chronic (p = .97) intervention. In patients with IIH, median stiffness pattern score was greater than in control individuals (0.25 vs 0.15, p < .001) and decreased after chronic (0.23, p = .11) but not acute (0.25, p = .49) intervention. Median occipital lobe stiffness was 3.08 kPa in patients with IIH versus 2.94 kPa in control individuals (p = .07) and did not change after acute (3.24 kPa, p = .73) or chronic (3.10 kPa, p = .83) intervention. CONCLUSION. IIH is associated with a small pituitary and increased brain stiffness pattern score; both findings may respond to chronic interventions to lower ICP. CLINICAL IMPACT. The "partially empty sella" sign and brain stiffness pattern score may serve as dynamic markers of ICP in IIH.

Drugs repurposing: An approach to identify new hits against anticancer drug target TFIIH subunit p8.

Drug repositioning is one of the most effective approaches towards drug discovery and development. It involves the identification of new therapeutic indications of existing drugs. The present study evaluated several drugs for their ability to modulate activity of the p8 subunit of TFIIH complex. Negative modulation of p8 subunit activity disrupts protein-protein interactions (PPIs) among the subunits of TFIIH complex, and thereby the TFIIH-associated functions. TFIIH complex has key role in the transcription and nucleotide excision repair activity in cancerous cells. TFIIH complex has emerged as a privileged drug target in anticancer research. Out of 60 drugs, amlopipine (13), diltiazem (16), gemfibrozil (19), levocitrizine dihydrochloride (20), losartan potassium (22), clorthalidone (24), and escitalopram (28) showed interactions with subunit p8 in the ligand-protein binding and chemical shift perturbation studies. The Kd values were found to be between 0.25 and 1 mM. These drugs also caused thermal destabilization of the subunit p8 by negatively shifting the melting temperature by ≥ 2 °C. Molecular docking studies indicated the interaction of these drugs with important residues of p8-p52 complex, such as Glu48, Lys51, Glu496, and Glu455 via non-covalent interactions. This study has thereby identified 7 drugs that can be investigated further as potential anticancer drugs.

Transmantle and transvenous pressure gradients in cerebrospinal fluid disorders.

Hydrocephalus is the symptomatic endpoint of a variety of disease processes. Simple hydrodynamic models have failed to explain the entire spectrum of cerebrospinal fluid (CSF) disorders. Physical principles argue that for ventricles to expand, they must be driven by a force, Fishman's transmantle pressure gradient (TMPG). However, the literature to date, reviewed herein, is heterogenous and fails to consistently measure a TMPG. The venous system, like CSF, traverses the cerebral mantle, and thus analogous transparenchymal and transvenous pressure gradients have been described, reliant on the differential haemodynamics of the deep and superficial venous systems. Interpreting CSF disorders through these models provides new insights into the possible pathophysiological mechanisms underlying these diseases. However, until more sophisticated testing is performed, these models should remain heuristics.

Outcomes of optic nerve sheath fenestration from superomedial eyelid crease approach.

PURPOSE: The purpose of this study is to report the safety and outcomes of optic nerve sheath fenestration (ONSF) performed via superomedial eyelid crease approach. METHODS: A retrospective chart review was performed on patients undergoing superomedial eyelid crease ONSF at a single institution between 2014-2019. Data obtained included preoperative visual acuity (VA), mean deviation (MD) on visual field (VF), papilledema grade, intraoperative time, estimated blood loss, intraoperative complications and optic nerve sheath biopsy results. Postoperative month 6 (POM6) data collected included VA, MD, papilledema grade, and lid contour. Outcome measures included overall change in VA, MD, and papilledema grade at POM6. Statistical analysis was performed using STATA version 16 statistical software. Data analysis was done comparing all patients pre- and postoperatively. Additional subgroup analysis was performed on patients undergoing ONSF for IIH vs other indications, and on the contralateral unoperated eye. RESULTS: A total of 31 eyes of 24 patients were identified, four of whom were excluded due to being lost to follow-up. At POM6, improvement was seen in VA (p<0.001) across all groups. There was improvement in POM6 median papilledema grade and MD, but these did not reach statistical significance. Additional subgroup analysis on patients with IIH showed statistically significant improvement in POM 6 VA (p=0.009), papilledema (p=0.009) and MD (p<0.001), as well as VA improvement in the contralateral unoperated eye (p<0.001). CONCLUSIONS: Superomedial eyelid crease approach for ONSF is a safe and effective surgery in IIH and other conditions of excess pressure within the optic nerve sheath.

Diagnosis and treatment of idiopathic intracranial hypertension.

OBJECTIVE: To review and discuss the clinical presentation and treatment of idiopathic intracranial hypertension. DISCUSSION: Visual alterations and headache are the two main symptoms of idiopathic intracranial hypertension, although additional features including cranial nerve palsies, cognitive deficits, olfactory deficits and tinnitus are not uncommon. The headache associated with idiopathic intracranial hypertension frequently has a migrainous phenotype. The underlying cause of the disorder has not yet been elucidated. Several hypotheses have been postulated but none of them can explain the full clinical picture. Therapeutic options remain limited, focusing mainly on reduction in body weight and the reduction of CSF production with carbonic anhydrase inhibitors. CONCLUSION: The accurate diagnosis of idiopathic intracranial hypertension is essential as visual deterioration due to papilledema may be irreversible. Given its phenotypic similarity and frequent overlap with chronic migraine it is essential to consider idiopathic intracranial hypertension in the diagnostic workup of chronic headache; in particular, when considering its increasing prevalence. Understanding in detail the pathophysiological mechanisms behind the associated headache would also allow study of current and future therapeutic options in a structured way.

Infantile idiopathic intracranial hypertension in the setting of recent laminectomy and filum lysis for tethered cord syndrome: a case report and literature review.

We present an 8-month old male status post simple tethered cord release with idiopathic intracranial hypertension.

Utility of Point-of-Care Ultrasound in the Diagnosis of Idiopathic Intracranial Hypertension in the Emergency Department.

BACKGROUND: Emergency physicians are frequently required to identify and triage patients with increased intracranial pressure (ICP). Idiopathic intracranial hypertension (IIH) is a possible cause that must be considered. Its prognosis depends on prompt recognition and treatment, and progression of the disease can lead to permanent vision loss and considerable morbidity. Point-of-care ultrasound can rapidly identify elevated ICP. Measurements of the optic nerve sheath diameter (ONSD) and optic disc elevation (ODE) can act as surrogates for ICP. CASE SERIES: We describe five cases in which ultrasound was used to identify increased ICP and aid clinical decision-making. In several of the cases, ultrasound was used to confirm a suspicion for IIH and initiate therapy while awaiting the results of a more time-consuming and technically challenging test, such as lumbar puncture or optical coherence tomography. One of the patients was pregnant, and sonographic evidence of elevated ICP helped avoid exposing the patient to unnecessary radiation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Ultrasound is a quick and versatile tool for screening patients with neurologic symptoms, and when integrated into the proper clinical context, can reduce the use of more invasive tests. It can be particularly useful in patients with pathology that may not show abnormalities on computed tomography scan or in whom lumbar puncture is technically difficult, making patients at risk for IIH well-suited to examination by ultrasound. We use a cutoff of 5 mm for ONSD and 0.6 mm for ODE, though there are no universally agreed on cutoff values.

The role of ICP monitoring in paediatric IIH.

INTRODUCTION: Diagnosis of idiopathic intracranial hypertension (IIH) in children is an extrapolation of the guidelines suggested for adult population. Lumbar puncture (LP) plays a crucial role in the diagnosis. The diagnosis of IIH at times is solely dependent on the interpretation of the opening pressure (OP). Unfortunately, LP-OP can vary due circumstantial parameters and therefore may be an unreliable form of intracranial pressure (ICP) measurement. Confirming the diagnosis based (as suggested by guidelines) on LP-OP in a doubtful clinical situation would be inappropriate. The aim of our study was to analyse the reliability of LP-OP and importance of ICP monitoring in situations where diagnosis of IIH was questionable. METHODS: Retrospective review of all children with diagnosis of IIH over a 10-year period was conducted. Children who underwent ICP monitoring (ICPM) were selected. We considered 2 LP-OP values-last LP (lLP) and the mean LP (mLP) for analysis. ICPM and LP-OP were compared. Follow-up till last clinic visit was also considered for long-term outcome. RESULTS: Eleven children (male 3; female 8) were included in the study. Mean delay between LP and ICPM was 112.8 days (17-257 days). There was lack of correlation between LP-OP and ICP in 9 children. ICP monitoring refuted the diagnosis of IIH in 80% of children and prevented exposure to unnecessary medical and surgical intervention. There was 1complication with ICPM. In 90% of children, there was no progression of symptoms following a decision based on ICP monitoring on long-term follow-up (mean, 36.5 months). CONCLUSION: When the diagnosis of IIH is in doubt, LP may be unreliable and formal ICP monitoring is advised.

Telemetric intracranial pressure monitoring in children.

PURPOSE: Repeated intracranial pressure (ICP) measurements are essential in treatment of patients with complex cerebrospinal fluid (CSF) disorders. These patients often have a long surgical history with numerous invasive lumbar or intracranial pressure monitoring sessions and/or ventriculoperitoneal (VP) shunt revisions. Telemetric ICP monitoring might be an advantageous tool in treatment of these patients. In this paper, we evaluate our experience with this technology in paediatric patients. METHODS: During a 4-year period, we implanted telemetric ICP sensors (Raumedic NEUROVENT-P-tel) in 20 paediatric patients to minimise the number of future invasive procedures. Patients were diagnosed with hydrocephalus, idiopathic intracranial hypertension (IIH) or an arachnoid cyst. Most patients (85%) had a VP shunt at the time of sensor implantation. RESULTS: In total, 32 sensors were inserted in the 20 patients; the cause of re-implantation was technical malfunction of the implant. One sensor was explanted due to wound infection and one due to skin erosion. We experienced no complications directly related to the implantation/explantation procedures. A total of 149 recording sessions were conducted, including 68 home monitoring sessions. The median implantation period was 523 days with a median duration of clinical use at 202 days. The most likely consequence of a recording session was non-surgical treatment alteration (shunt valve adjustment or acetazolamide dose adjustment). CONCLUSION: Telemetric ICP monitoring in children is safe and potentially decreases the number of invasive procedures. We find that telemetric ICP monitoring aids the clinical management of patients with complex CSF disorders and improves everyday life for both patient and parents. It allows continuous ICP measurement in the patient's home and thereby potentially reducing hospitalisations, leading to significant cost savings.

Headache attributed to IIH: clinical evolution in IHS criteria through the years.

Idiopathic intracranial hypertension (IIH) is a condition characterized by increased intracranial pressure without a detectable cause. The most common symptom of IIH is a headache, which occurs in almost all cases at the time of diagnosis with various headache phenotypes. In clinical practice, diagnosis of headache attributed to IIH is given referring to the International Headache Society (IHS) criteria of the International Classification of Headache Disorders. In the present publication, we consider how the IHS diagnostic criteria for headache attributed to intracranial idiopathic hypertension have evolved through the years.

The significance of intra-abdominal pressure in neurosurgery and neurological diseases: a narrative review and a conceptual proposal.

Intra-abdominal pressure (IAP) is a physiological parameter that has gained considerable attention during the last few decades. The incidence of complications arising from increased IAP, known as intra-abdominal hypertension (IAH) or abdominal compartment syndrome in critically ill patients, is high and its impact is significant. The effects of IAP in neurological conditions and during surgical procedures are largely unexplored. IAP also appears to be relevant during neurosurgical procedures (spine and brain) in the prone position, and in selected cases, IAH may affect cerebrospinal fluid drainage after a ventriculoperitoneal shunt operation. Furthermore, raised IAP is one of the contributors to intracranial hypertension in patients with morbid obesity. In traumatic brain injury, case reports described how abdominal decompression lowers intracerebral pressure. The anatomical substrate for transmission of the IAP to the brain and venous system of the spine is the extradural neural axis compartment; the first reports of this phenomenon can be found in anatomical studies of the sixteenth century. In this review, we summarize the available knowledge on how IAP impacts the cerebrospinal venous system and the jugular venous system via two pathways, and we discuss the implications for neurosurgical procedures as well as the relevance of IAH in neurological disorders.

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

BACKGROUND: Dural venous sinus stenting (DVSS) is an accepted treatment option in selected patients with medically refractory idiopathic intracranial hypertension and obstructive venous outflow physiology prior to cerebrospinal flow diversion (CSFD) surgery. There are no randomized controlled studies focusing on outcomes and complication rates for dural venous sinus stenting. PURPOSE: We present the largest comprehensive meta-analysis on DVSS for idiopathic intracranial hypertension (IIH) focusing on success rates, complications, and re-stenting rates to date. We also present a simplified approach to direct retrograde internal jugular vein (IJ) access for DVSS that allows for expedited procedures. MATERIALS AND METHODS: We performed a retrospective electronic PubMed query of all peer-reviewed articles in the last 15 years between 2003 to 2018. We included all patients who underwent dural venous sinus stenting for a medically refractive IIH and excluded articles without sufficient data on outcomes, complication rates and re-stenting rates. We also evaluated and compared outcomes in patients undergoing direct retrograde IJ access DVSS to traditional transfemoral vein access. RESULTS: A total of 29 papers and 410 patients who underwent DVSS met criteria for inclusion. DVSS was associated with high technical success [99.5%], low rates of repeated procedure [10%], and low major complication rates [1.5%]. CONCLUSION: Our retrospective comprehensive review of DVSS for medically refractory IIH suggests that stenting in appropriately chosen patients is associated with low complication rates, high technical success, and low repeat procedure rates.