Update on the Surgical Management of Idiopathic Intracranial Hypertension

Novel Approaches to the Treatment of Idiopathic Intracranial Hypertension

PURPOSE OF REVIEW

Idiopathic intracranial hypertension (IIH) typically affects women of childbearing age, is associated with recent weight gain, and can result in debilitating headache as well as papilledema that can cause vision loss. There have been advances in the medical and surgical treatment of affected patients with IIH that can improve outcomes and tolerability of therapy.

RECENT FINDINGS

Medical treatment with agents that lower intracranial pressure through pathways other than carbonic anhydrase inhibition are being developed, and medically-directed weight loss as well as bariatric surgery now may be considered as primary therapy. New surgical options including venous sinus stenting have shown efficacy even with cases of severe vision loss. Our treatment options for IIH patients are becoming more diverse, and individualized treatment decisions are now possible to address specific components of the patient's disease manifestations and to lead to IIH remission.

Opioid Prescribing Patterns Following Lateral Skull Base Spontaneous Cerebrospinal Fluid Leak Repair

OBJECTIVE

To characterize the opioid prescribing patterns for and requirements of patients undergoing repair of spontaneous cerebrospinal fluid (sCSF) leaks of the lateral skull base.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Adults with lateral skull base sCSF leaks who underwent repairs between September 1, 2014, and December 31, 2020.

MAIN OUTCOME MEASURE

Mean morphine milligram equivalents (MMEs) of opioids dispensed to inpatients and prescribed at discharge, additional pain control medications dispensed, and outpatient additional opioid requests were compared between groups.

RESULTS

Of 78 patients included, 46 (59%) underwent repair via a transmastoid (TM), 6 (7.7%) via a middle cranial fossa (MCF), and 26 (33.3%) via a combined TM-MCF approach. Inpatients received a mean of 21.3, 31.4, and 37.6 MMEs per day during admission for the TM, MCF, and combined TM-MCF approaches, respectively ( p = 0.019, ηp 2 = 0.101). Upon discharge, nearly all patients (n = 74, 94.9%) received opioids; 27.3, 32.5, and 37.6 MMEs per day were prescribed after the TM, MCF, and TM-MCF approaches, respectively ( p = 0.015, ηp 2 = 0.093). Five (6.4%) patients requested additional outpatient pain medication, after which three were prescribed 36.7 MMEs per day. Patients with idiopathic intracranial hypertension required significantly more inpatient MMEs than those without (41.5 versus 25.2, p = 0.02, d = 0.689), as did patients with a history of headaches (39.6 versus 23.6, p = 0.042, d = 0.684).

CONCLUSIONS

Patients undergoing sCSF leak repair via the MCF or TM-MCF approaches are prescribed more opioids postoperatively than patients undergoing the TM approach. Patients with a history of headaches or idiopathic intracranial hypertension might require more opioids postoperatively.

Which OCT Measure of the Optic Nerve Head Improves Fastest? Towards Optimizing Early Detection of Resolving Papilledema in Children

Purpose

Optical coherence tomography (OCT) has been used to monitor papilledema. This study aims to determine which OCT-derived measures of the optic nerve head (ONH) detect resolving papilledema in children faster than standard OCT measures.

Methods

Children (≤18 years of age) with papilledema who completed optic nerve SD-OCT pretreatment and had evidence of treatment response on one or more follow-up OCTs within 4 months were included. Standard (mean circumpapillary retinal nerve fiber layer [cpRNFL] thickness), device-derived (per-quadrant cpRNFL) and custom (ONH height, maximum Bruch's membrane displacement [BMD], ONH volume [ONHV], and BMD volume) OCT measures were calculated. Per-eye generalized estimating equations (GEEs) modelled changes in device-derived and custom measures as a function of mean cpRNFL to identify those measures that resolved faster during early (0-2 months) follow-up. Mean cpRNFL coefficients of greater than 1 indicated faster resolving papilledema.

Results

We included 52 eyes of 29 children (mean age, 12.8 years; 72.4% female). In analysis of early follow-up visits (38 eyes from 22 children), nasal cpRNFL and maximum BMD in each quadrant resolved faster than mean cpRNFL (GEE coefficients range, 1.14-3.37). Inferior cpRNFL, superior, nasal, and inferior ONH heights and ONHV resolved slower than mean cpRNFL (GEE coefficients range, 0.67-0.87).

Conclusions

Nasal cpRNFL is a promising device-derived OCT measure for the early detection of resolving papilledema in children compared with mean cpRNFL. Maximum BMD, a custom measure, also shows promise, but its calculation has not yet been incorporated into commercial OCT devices.

Translational Relevance

This study guides the optimal use of OCT in capturing resolving papilledema in children.

A Man's Struggle With Idiopathic Intracranial Hypertension: A Unique Case Study

We report a unique case of a 53-year-old male with idiopathic intracranial hypertension (IIH), predominantly affecting overweight young women. The patient, known to have diabetes mellitus, familial Mediterranean fever, and dyslipidemia, presented with blurred vision and throbbing headaches. Clinical examination, brain MRI/MRV, and a lumbar puncture confirmed the IIH diagnosis. Management with acetazolamide improved the patient's symptoms significantly. This case highlights the potential for IIH occurrence in men and underscores the need for early diagnosis and intervention to prevent potential visual impairment, typically more severe in male patients.

Idiopathic Intracranial Hypertension: Implications for the Otolaryngologist

Idiopathic intracranial hypertension (IIH) is a triad of headaches, visual changes, and papilledema in the absence of a secondary cause for elevated intracranial pressure. There is an association with obesity, and the incidence is rising in parallel with the obesity epidemic. Sometimes these patients present to an otolaryngologist with complaints like tinnitus, dizziness, hearing loss, and otorrhea or rhinorrhea from cerebrospinal fluid leak. IIH diagnosis in conjunction with neurology and ophthalmology, including neuroimaging and lumbar puncture with opening pressure, is key to managing of this condition. Otolaryngologists should recognize IIH as a possible diagnosis and initiate appropriate referrals and treatment.

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

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

Idiopathic intracranial hypertension in males

Idiopathic intracranial hypertension (IIH) is a neurological condition characterized by increased intracranial pressure without an underlying intracranial pathology. This condition is rarely encountered in men and it predominantly affects obese women of childbearing age. We present an interesting case of IIH in a male patient who presented with acute severe vision loss over 2 weeks and was successfully treated via surgery. Although IIH is less common in men than in women, men are more likely to develop vision loss, which is usually severe and less likely to respond to medical treatment. Therefore, surgical intervention might be considered early in the treatment of men with rapidly progressive visual loss. Further prospective studies are needed to evaluate the role of early surgical intervention in comparison to medical treatment in this group of patients.

Headaches Due to Low and High Intracranial Pressure

PURPOSE OF REVIEW

Headache disorders attributed to low and high intracranial pressure are commonly encountered in specialty headache practices and may occur more frequently than realized. While the headaches resulting from intracranial pressure disorders have what are conventionally thought of as defining characteristics, a substantial minority of patients do not manifest the "typical" features. Moreover, patients with intracranial pressure disorders may also have a preexisting primary headache disorder. Heightening the complexity of the presentation, the headaches of intracranial pressure disorders can resemble the phenotype of a primary disorder. Lastly, patients with so-called intracranial "hypotension" often have normal CSF pressure and neuroimaging studies. Thus, a high index of suspicion is needed. The published literature has inherent bias as many types of specialists evaluate and treat these conditions. This article reviews the key points to emphasize the history, examination, and laboratory evaluation of patients with intracranial pressure disorders from a neurologist's perspective.

RECENT FINDINGS

Lumbar puncture opening pressure in patients with spontaneous intracranial hypotension was low enough to meet diagnostic criteria (≤60 mm CSF) in only 34% of patients in one study. Most patients had an opening pressure in the low normal to normal range, and 5% had an opening pressure of 200 mm CSF or more. Diskogenic microspurs are a common cause of this syndrome. The Idiopathic Intracranial Hypertension Treatment Trial found that most participants had a headache phenotype resembling migraine or tension-type headache. No "typical" or characteristic headache phenotype was found, and headache-related disability was severe at baseline. Headache disability did not correlate with the lumbar puncture opening pressure at baseline or at the 6-month primary outcome period. Although participants who were randomly assigned to acetazolamide had a lower mean CSF opening pressure at 6 months, headache disability in that group was similar to the group who received placebo.

SUMMARY

Significant overlap is seen in the symptoms of high and low CSF pressure disorders and in those of primary headache disorders. Neurologists are frequently challenged by patients with headaches who lack the typical clinical signs or imaging features of the pseudotumor cerebri syndrome or spontaneous intracranial hypotension. Even when characteristic symptoms and signs are initially present, the typical features of both syndromes tend to lessen or resolve over time; consider these diagnoses in patients with long-standing "chronic migraine" who do not improve with conventional headache treatment. While the diagnostic criteria for pseudotumor cerebri syndrome accurately identify most patients with the disorder, at least 25% of patients with spontaneous intracranial hypotension have normal imaging and over half have a normal lumbar puncture opening pressure. Detailed history taking will often give clues that suggest a CSF pressure disorder. That said, misdiagnosis can lead to significant patient morbidity and inappropriate therapy.

Surgical intervention in pediatric intracranial hypertension: incidence, risk factors, and visual outcomes

PURPOSE

To evaluate the incidence of surgical intervention in pediatric intracranial hypertension (IH), evaluate the visual outcomes of surgically managed patients, and identify potential predictors for surgical intervention.

METHODS

The medical records of patients with primary and secondary IH at Nationwide Children's Hospital from 2010 to 2017 were reviewed retrospectively. Presenting characteristics of medically and surgically managed patients were compared, and the clinical courses of surgically managed patients were reviewed.

RESULTS

A total of 129 medically and 14 surgically managed patients were included. The surgical incidence was 9.8%. Final visual acuity in 27 of 28 surgically managed eyes was 20/25 or better. In combined primary and secondary IH patients, elevations in body mass index (BMI; OR = 1.06; 95% CI, 1.01-1.11; P = 0.022) and lumbar puncture opening pressures ≥52 cm H₂O (OR = 6.17; 95% CI, 1.93-19.67; P = 0.002) were significantly associated with the likelihood of surgical intervention when assessed by univariate logistic regression; grade of papilledema >2 was of marginal significance. After controlling for BMI, a lumbar puncture opening pressure of ≥52 cm H₂O was more likely to result in surgery (adjusted OR = 4.69; 95% CI = 1.39-15.98; P = 0.013).

CONCLUSIONS

Most pediatric IH can be treated medically. Patients with lumbar puncture opening pressures ≥52 cm H₂O at the time of diagnosis are at a higher risk of surgical intervention and should be monitored closely. Elevations in presenting BMI and grade of papilledema may also increase the odds of surgery.

Cranial morcellation decompression for refractory idiopathic intracranial hypertension in children

BACKGROUND

Primary idiopathic intracranial hypertension (PIIH) in children is rare and has a poorly understood pathophysiology. It is characterized by raised intracranial pressure (ICP) in the absence of an identified brain lesion. Diagnosis is usually confirmed by the measurement of a high cerebrospinal fluid (CSF) opening pressure and exclusion of secondary causes of intracranial hypertension. Refractory PIIH may lead to severe visual impairment. The purpose of this study was to evaluate a cranial morcellation decompression (CMD) technique as a new surgical alternative to stabilize intracranial pressure in PIIH.

MATERIALS AND METHODS

A literature review was carried out, disclosing only 7 pediatric cases of PIIH treated with surgical skull expansion. In addition, we describe here one case of our own experience treated by CMD.

CONCLUSIONS

CMD surgery is a safe and effective option to control refractory PIIH in selected patients.

Ventriculoperitoneal shunt treatment in a pregnant renal transplant recipient with idiopathic intracranial hypertension: Case report and review of the literature

Idiopathic intracranial hypertension (IIH) is a relatively uncommon disorder characterised by raised intracranial pressure without an established pathogenesis. Diagnosis of IIH requires the demonstration of symptoms and signs referable only to elevated intracranial pressure; cerebrospinal fluid (CSF) opening pressure >25cm H₂O measured in the lateral decubitus position; normal CSF composition; and no evidence for an underlying structural cause demonstrated by using MRI or contrast-enhanced CT scan for typical patients and MRI and MR venography for atypical patients such as man, children and those with low body mass index. We present a 38-year old primigravid renal transplant patient at 7 weeks of gestation who presented with 2 weeks of intense, throbbing, holocranial headache, nausea, vomiting, photophobia, diplopia and progressive visual loss. When medical treatment fails and/or not appropriate to use due to the reported of teratogenic risks in pregnant women, surgical interventions gain importance. In this particular patient, venticuloperitoneal shunt was chosen as the CSF diversion technique. In this case report indications, contraindications in addition to outcomes regarding headache, vision loss and the resolution of papilloedema of the present surgery options for IIH are discussed.

Fulminant Idiopathic Intracranial Hypertension and Venous Stasis Retinopathy Resulting in Severe Bilateral Visual Impairment

Purpose

To report a complicated case of fulminant idiopathic intracranial hypertension and concomitant venous stasis retinopathy leading to postpapilledema optic atrophy.

Methods

Case report.

Results

A 34-year-old morbidly obese woman with a history of idiopathic intracranial hypertension (IIH) presented with a 1-month history of bilateral vision loss, diplopia, and left eye pain after being lost to follow-up for 6 years. Fundus examination revealed florid papilledema with venous tortuosity bilaterally. Brain and orbit magnetic resonance imaging showed bilateral globe flattening, intraocular optic nerve swelling in both eyes, and no abnormality on magnetic resonance venography. After additional workup including lumbar puncture with an opening pressure of 55 cm H2O, a diagnosis of IIH was confirmed. Medical treatment with oral carbonic anhydrase inhibitors was initiated, followed by same-day bilateral optic nerve sheath decompression and ventriculoperitoneal shunt placement the following week. Fundus examination 2 months later revealed a persistent blood and thunder fundus suggestive of bilateral central retinal vein occlusions. Over the course of 6 months, both eyes displayed postpapilledema optic atrophy with light perception and hand motion vision in the right and left eyes, respectively. On Goldmann perimetry, the patient had vague limited isolated responses in both eyes to the largest target.

Conclusions

Fulminant IIH can present with profoundly blinding complications recalcitrant to aggressive medical and surgical intervention. Central retinal vein occlusion is an uncommon blinding complication of IIH.

An update on idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is still a grey area in the knowledge of the aetiology, diagnosis and management of neurosurgical diseases. The definition of IIH has been reviewed over time and many hypotheses have been expressed as cause of the disease. The literature supplies very little evidence-based information to guide our decision-making process when it comes to treat the disease. In this review we sum up the latest information regarding the aetiology and therapy of IIH. Additionally, we make an attempt to unify the diagnostic criteria of Dandy, Friedman and Wall established from 1937 to date.

METHOD

In this narrative review, we attempt to update the current standpoint to IIH, evaluate the input until now and consider future directions for research. The vast majority of the literature consisted of cohort studies, case control studies, systematic reviews and other narrative reviews.

RESULTS

Pathophysiology: The incidence of IIH is steadily increasing. Several pathophysiological theories have been proposed in the literature based on the flow of cerebrospinal fluid.

DIAGNOSIS

We attempt to fuse all the three diagnostic approaches published in the literature that detect IIH, while preserving the individual characteristics of each approach.

TREATMENT

Based on evidence-based trials, the current use of acetazolamide in comparison with placebo or with topiramate has been evaluated. In the interventions' field, there seems to be a consonance about the alarming symptoms and what the most suitable operation is in each case. There is some disagreement about the indications for venous sinus transversus stenting and its risk/benefit ratio.

CONCLUSIONS

Until now there is no class I guideline to which our decision-making can be based on for the management of IIH. A lack of systematic reviews and randomised control trials has been noted. If we focused our research on that, we could develop a standardised treatment protocol.

Surgically managed idiopathic intracranial hypertension in adults: a single centre experience

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is a rare condition that is often managed conservatively. In patients with aggressive progression of the disease surgical options are considered. There are few data on the outcomes of these patients when surgically managed. We describe our experience of surgically managed IIH and the outcomes of these patients, in particular the surgical revision rate and interventions required for resolution of symptoms.

METHODS

A retrospective review of all patient files coded with benign intracranial hypertension, idiopathic intracranial hypertension or pseudotumour cerebri was undertaken. Files were searched with the date of diagnosis and the date these patients were referred for surgical intervention. The surgical interventions and complications were then documented and note was made of the number of inpatient admissions and days spent in hospital.

RESULTS

From 2000-2013, 79 patients were identified as patients with IIH that had required surgical intervention; 52 % required further surgical intervention. The average number of surgical interventions was 5.6. For patients requiring further intervention the average number of surgical interventions was 8.6. On average patients with IIH also spent 42 inpatient days in neurosurgical beds, whilst those patients who required further intervention spent 63 days on average in neurosurgical beds. The length of the average individual admission was longer for patients requiring repeated surgical interventions.

CONCLUSION

Based on our experience, patients that require surgical management of IIH frequently require further surgical interventions to control symptoms and manage complications of CSF diversion surgery. Those that require such further intervention on average will have six further operations and spend significantly longer in hospital. Lumboperitoneal (LP) shunting is an effective first line surgical intervention for 52 % of our patient cohort. This sub-group of patients therefore requires specialist neurosurgical input for this long-term and challenging pathological process.

A comparison of lumboperitoneal and ventriculoperitoneal shunting for idiopathic intracranial hypertension: an analysis of economic impact and complications using the Nationwide Inpatient Sample

OBJECT

Complications following lumboperitoneal (LP) shunting have been reported in 18% to 85% of cases. The need for multiple revision surgeries, development of iatrogenic Chiari malformation, and frequent wound complications have prompted many to abandon this procedure altogether for the treatment of idiopathic benign intracranial hypertension (pseudotumor cerebri), in favor of ventriculoperitoneal (VP) shunting. A direct comparison of the complication rates and health care charges between first-choice LP versus VP shunting is presented.

METHODS

The Nationwide Inpatient Sample database was queried for all patients with the diagnosis of benign intracranial hypertension (International Classification of Diseases, Ninth Revision, code 348.2) from 2005 to 2009. These data were stratified by operative intervention, with demographic and hospitalization charge data generated for each.

RESULTS

A weighted sample of 4480 patients was identified as having the diagnosis of idiopathic intracranial hypertension (IIH), with 2505 undergoing first-time VP shunt placement and 1754 undergoing initial LP shunt placement. Revision surgery occurred in 3.9% of admissions (n = 98) for VP shunts and in 7.0% of admissions (n = 123) for LP shunts (p < 0.0001). Ventriculoperitoneal shunts were placed at teaching institutions in 83.8% of cases, compared with only 77.3% of first-time LP shunts (p < 0.0001). Mean hospital length of stay (LOS) significantly differed between primary VP (3 days) and primary LP shunt procedures (4 days, p < 0.0001). The summed charges for the revisions of 92 VP shunts ($3,453,956) and those of the 6 VP shunt removals ($272,484) totaled $3,726,352 over 5 years for the study population. The summed charges for revision of 70 LP shunts ($2,229,430) and those of the 53 LP shunt removals ($3,125,569) totaled $5,408,679 over 5 years for the study population.

CONCLUSIONS

The presented results appear to call into question the selection of LP shunt placement as primary treatment for IIH, as this procedure is associated with a significantly greater likelihood of need for shunt revision, increased LOS, and greater overall charges to the health care system.

Papilledema: epidemiology, etiology, and clinical management

Papilledema is optic disc swelling due to high intracranial pressure. Possible conditions causing high intracranial pressure and papilledema include intracerebral mass lesions, cerebral hemorrhage, head trauma, meningitis, hydrocephalus, spinal cord lesions, impairment of cerebral sinus drainage, anomalies of the cranium, and idiopathic intracranial hypertension (IIH). Irrespective of the cause, visual loss is the feared morbidity of papilledema, and the main mechanism of optic nerve damage is intraneuronal ischemia secondary to axoplasmic flow stasis. Treatment is directed at correcting the underlying cause. In cases where there is no other identifiable cause for intracranial hypertension (ie, IIH) the available options include both medical and surgical modalities. Weight loss and diuretics remain the mainstays for treatment of IIH, and surgery is typically reserved for patients who fail, are intolerant to, or non-compliant with maximum medical therapy.

Anatomic and visual function outcomes in paediatric idiopathic intracranial hypertension

BACKGROUND

There is a paucity of literature describing risk factors for vision loss in paediatric idiopathic intracranial hypertension (IIH). We investigate the final visual function, spectral domain optical coherence tomography (SD-OCT) and enhanced depth imaging (EDI)-OCT findings in children with papilledema caused by IIH.

METHODS

Medical records of 31 patients with paediatric IIH (age ≤17 years) were retrospectively reviewed. Optic disc photographs on presentation and automated perimetry, SD-OCT and EDI-OCT imaging on final follow-up visit were statistically analysed to identify patient characteristics and anatomic findings associated with irreversible vision loss.

RESULTS

Permanent visual acuity or visual field loss developed in 19% of study eyes. Papilledema of modified Frisén grade ≥3 on presentation was highly predictive of permanent vision loss (p<0.001), while associations between pubertal status and visual function outcome failed to reach statistical significance. SD-OCT revealed optic atrophy in 13% and photoreceptor loss in 19% of eyes, with both findings highly associated with vision loss (p<0.0001). Optic disc drusen was noted in 48% of study eyes by EDI-OCT but was not found to be predictive of visual outcome.

CONCLUSIONS

Clinical observation of high papilledema grade on presentation is predictive of poor visual outcomes. Vision loss is associated not only with optic atrophy but also with photoreceptor damage. Interestingly, a high proportion of study eyes had optic disc drusen, which was not associated with vision loss, but can be a diagnostic challenge in distinguishing true papilledema from pseudopapilledema.