Idiopathic intracranial hypertension (pseudotumor cerebri): recognition, treatment, and ongoing management

A Perspective on the Permeability of Cocrystals/Organic Salts of Oral Drugs

According to the BCS classification system, the differentiation of drugs is based on two essential parameters of solubility and permeability, meaning the latter is as pivotal as the former in creating marketable pharmaceutical products. Nevertheless, the indispensable role of permeability in pharmaceutical cocrystal profiles has not been sufficiently cherished, which can be most probably attributed to two principal reasons. First, responsibility may be on more user-friendly in vitro measurement procedures for solubility compared to permeability, implying the permeability measurement process seems unexpectedly difficult for researchers, whereas they have a complete understanding of solubility concepts and experiments. Besides, it may be ascribed to the undeniable attraction of introducing new crystal-based structures which mostly leaves the importance of improving the function of existing multicomponents behind. Bringing in new crystalline entities, to rephrase it, researchers have a fairly better chance of achieving high-class publications. Although the Food and Drug Administration (FDA) has provided a golden opportunity for pharmaceutical cocrystals to straightforwardly enter the market by simply considering them as derivatives of the existing active pharmaceutical ingredients, inattention to assessing and scaling up permeability which is intimately linked with solubility has resulted in limited numbers of them in the global pharmaceutical market. Casting a glance at the future, it is apprehended that further development in the field of permeability of pharmaceutical cocrystals and organic salts requires a meticulous perception of achievements to date and potentials to come. Thence, this perspective scrutinizes the pathway of permeation assessment making researchers confront their fear upfront through mapping the simplest way of permeability measurement for multicomponents of oral drugs.

Clinical outcomes of bariatric surgery in patients with obesity and idiopathic intracranial hypertension

INTRODUCTION

Obesity is a major risk factor for idiopathic intracranial hypertension (IIH). Effective therapeutics for preventing disease progression and alleviating symptoms are limited. This study aims to examine the effects of bariatric surgery on clinical outcomes of IIH.

METHODS

We retrospectively collected data from the medical record of 97 patients with obesity and an existing diagnosis of IIH who underwent primary bariatric surgery at the Cleveland Clinic health system in the USA between 2005 and 2023. Pre- and postoperative data on presence of symptoms and clinical markers of IIH (headaches, visual field defects, papilledema, visual symptoms), intracranial pressure, and usage of IIH medications were compared.

RESULTS

A total of 97 patients (98% female, median age 46.7 years, median BMI 48.3 kg/m2) with IIH who underwent bariatric surgery including Roux-en-Y gastric bypass (n = 66, 68%), sleeve gastrectomy (n = 27, 27.8%), and gastric banding (n = 4, 4.1%) were analyzed. In a median follow-up time of 3.0 years, the median total weight loss was 24% (interquartile range, 13-33%). There was a significant improvement in headache, papilledema, visual field deficits, and visual symptoms after bariatric surgery. The mean lumbar opening pressure before and after bariatric surgery was 34.8 ± 8.2 cm CSF and 24.2 ± 7.6 cm CSF, respectively, with a mean reduction of 10.7 cm CSF (95% confidence interval, 4.7 to 16.6), p = 0.003. The dosage of acetazolamide and topiramate, as well as the number of medications taken for IIH, decreased significantly after bariatric surgery (p < 0.001).

CONCLUSION

For patients who have obesity, bariatric surgery is a viable treatment modality for alleviation or improvement of symptoms of IIH.

Idiopathic intracranial hypertension as the initial presenting manifestation of systemic lupus erythematosus in a child

Idiopathic intracranial hypertension (IIH) is a diagnosis of exclusion characterized by features of raised intracranial pressure (ICP) in the absence of brain parenchymal lesion, vascular malformations, hydrocephalus, or central nervous system (CNS) infection. Commonly used other terms for this entity include benign intracranial hypertension (BIH) or pseudotumor cerebri. Few case reports of systemic lupus erythematosus (SLE) presenting as IIH are available in the literature. We report a 12-year-old girl presented with chronic holocranial headache and occasional episodes of projectile vomiting for the last 6 months and then developed blurring of vision for the last month. She fulfilled the criteria for IIH. Subsequent evaluation revealed a diagnosis of SLE. The occurrence of IIH in SLE is not coincidental and is reported in 1%-5.4% of patients with SLE. Though corticosteroids have not been widely used in IIH, underlying SLE warranted administering corticosteroids with subsequent complete resolution of IIH. Pediatricians, neurologists, intensivists, and ophthalmologists should consider SLE as a differential diagnosis in children presenting with IIH.

Ventriculo-atrial shunt in idiopathic intracranial hypertension

PURPOSE

CSF diversion  is a recognised intervention in idiopathic intracranial hypertension (IIH), particularly in the presence of vision-threatening papilledema. Although ventriculo-atrial (VA) shunt insertion is a routine neurosurgical procedure, ventriculoperitoneal and lumboperitoneal shunts have been mostly used in this particular indication. This study aims to look at a single centre's experience with VA shunts in idiopathic intracranial hypertension (IIH).

METHODS

Retrospective case series with a review of electronic records over a 10-year period; exclusion criteria were duplication of same shunt insertion, no VA shunt insertion, paediatric patients and indication other than IIH. Notes were reviewed for demographics, shunt survival (defined by time prior to revision) and reasons for revision.

RESULTS

Eight VA shunt procedures were identified in 6 patients (mean age at insertion 34 ± 10 years) with a mean follow-up of 58 ± 25 months. All shunts were secondary procedures; 2 revisions from lumbo-pleural, 2 from ventriculopleural, 2 from ventriculoatrial and one each from ventriculoperitoneal and combined lumbo-/ventriculoperitoneal. At 50 months, 75% of VA shunts had survived, compared to only 58.3% of VPleural shunts in patients with IIH. Revisions were required due to acute intracranial bleed (1 case)-revised at day 1, and thrombus at distal site (1 case)-revised at day 57. Both shunts were later reinserted. From the latest clinic letters, all patients had their treatment optimised with this procedure, although only two patients had documented resolved papilloedema post-procedure.

CONCLUSIONS

Ventriculo-atrial shunts are a safe and efficacious alternative option for CSF diversion in IIH. In this series, only 1 shunt was revised for a VA shunt-specific complication.

Doxycycline-Induced Intracranial Hypertension Presenting as Unilateral Pulsatile Tinnitus

Background

Pulsatile tinnitus (PT) is increasingly recognized as a cardinal symptom of idiopathic intracranial hypertension (IIH). However, clinicians should remain aware of other causes of nonidiopathic or secondary intracranial hypertension manifesting as PT. We present 2 patients with isolated PT (without accompanying headache, blurred vision, and papilledema) thought to be secondary to tetracycline-induced intracranial hypertension. To our knowledge, these are the first cases of PT as the presenting symptom of this condition.

Cases

A 41-year-old female (body mass index [BMI] 29 kg/m2) with ocular rosacea was initially treated with minocycline. Shortly after transitioning to oral doxycycline and erythromycin eye ointment, she noted left-sided PT. Her PT resolved after discontinuing doxycycline. In a second case, a 39-year-old female (BMI 19 kg/m2) with acne presented with a three-year history of left-sided PT while on long-term oral doxycycline for many years. She denied visual or auditory changes and atypical headaches. MRI findings were concerning for intracranial hypertension. Three months later, the patient was seen by neuro-ophthalmology, with findings suggesting prior papilledema. The patient reported PT improvement after discontinuing doxycycline.

Conclusions

This case series highlights 2 cases of isolated PT as the sole symptom of intracranial hypertension that resolved with tetracycline cessation. The presentation and unexpected improvement following tetracycline discontinuation are atypical compared with previous reports of tetracycline-induced intracranial hypertension. Clinicians should maintain a high index of suspicion for all types of intracranial hypertension (idiopathic and secondary), even in patients with a lower BMI. Current and prior medications should be reviewed when considering the etiology of intracranial hypertension.

Neuroimaging in the diagnosis and treatment of intracranial pressure disorders

OBJECTIVE

To review the clinical features, proposed pathophysiology, and the role of medical imaging in the diagnosis and treatment of idiopathic intracranial hypertension and spontaneous intracranial hypotension.

METHODS

The authors conducted a narrative review of the current literature on intracranial hypertension and hypotension syndromes, with a focus on imaging findings and role of neurointerventional radiology as a therapeutic option for these pathologies.

RESULTS

Idiopathic intracranial hypertension commonly presents in obese women of childbearing age, being headache and papilledema the main clinical manifestations. Characteristic radiological findings consist of increased cerebrospinal fluid around the optic nerve, partially empty sella turcica and stenosis of the transverse sinuses. Transverse sinus stenting is a treatment alternative that has proven valuable utility in the recent years. Spontaneous intracranial hypotension in most of cases presents with orthostatic headache and has predilection for female population. The typical radiological features in the brain consist of subdural fluid collections, enhancement of the dura, engorgement of the venous structures, pituitary enlargement, and sagging of the brain. In this pathology, a cerebrospinal fluid leak in the spine associated with a defect in the dura, meningeal diverticulum, or a cerebrospinal fluid-venous leak must be actively ruled out.

CONCLUSIONS

Neurologic complaints secondary to changes in intracranial pressure exhibit certain clinical features that in combination with fairly specific radiological patterns allow a highly accurate diagnosis. The diverse specialists in neurosciences should be aware of the multiple image modalities in the study of these syndromes as well as the treatment alternatives by neurointerventional radiology.

Visual outcomes of idiopathic intracranial hypertension in a neuro-ophthalmology clinic in Jeddah, Saudi Arabia

PURPOSE

Idiopathic intracranial hypertension (IIH) is a disorder with elevated intracranial pressure more than 250 mm H2O, without evidence of meningeal inflammation, space-occupying lesion, or venous thrombosis. In this study, we aim to study the clinical profile, evaluation, management, and visual outcome in a hospital-based population of IIH cases in Jeddah.

METHODS

This is a retrospective observational cohort study that included the medical records of all patients referred to neuro-ophthalmology service for evaluation of papilledema. The medical records have been reviewed from October 2018 to February 2020 at Jeddah Eye Hospital, Saudi Arabia. A total of 51 patients presented with papilledema in the studied period. Forty-seven patients met our inclusion criteria and were included in the study.

RESULTS

The study found that the incidence rate of IIH is 16:100 of the referred cases to the neuro-ophthalmology clinic. Most of the patients were females (41, 91.2%), with a mean age of presentation of 32 ± 11 years. The most common presenting symptom was headache (40 patients, 88.8%), followed by transient visual obscuration (TVO) (20 patients, 44.4%), and reduced visual acuity (15 patients, 33.3%). All 45 patients were started on medical treatment with oral acetazolamide with four patients (8.8%) shifted to topiramate because of the lack of response or intolerance to acetazolamide while four patients (8.8%) underwent lumbar-peritoneal shunt because of inadequate control of the disease despite the treatment with medical therapy. For both eyes, the change in visual acuity across all assessment points was statistically significant. Nevertheless, there were no significant changes in the visual field findings among all of the compared assessment points.

CONCLUSION

The present study has shown that IIH-related papilledema is common in young female patients with headaches, TVOs, and reduced visual acuity. Those are the most common symptoms in our IIH population. Medical treatment and monitoring of IIH is efficient and should be considered to enhance the prognosis of IIH-related complications. In addition, the visual acuity and the visual field should be frequently monitored for these patients.

Familial non-obese idiopathic intracranial hypertension

Purpose

To report a series of cases of non-obese familial idiopathic intracranial hypertension.

Observation

One father and three offsprings (two brothers and one sister) with idiopathic intracranial hypertension and different phenotypic presentations.

Conclusion and Importance

Familial idiopathic intracranial hypertension may underrecognized and may not be associated with obesity. Symptomatic family members may need to be screened for IIH in some cases.

Increased Incidence of Pseudotumor Cerebri Syndrome Among Users of Tetracycline Antibiotics

BACKGROUND

To determine whether the use of a tetracycline-class antibiotic is associated with an increased risk of developing pseudotumor cerebri syndrome (PTCS).

METHODS

We identified patients in the University of Utah Health system who were prescribed a tetracycline-class antibiotic and determined what percentage of those individuals were subsequently diagnosed with PTCS secondary to tetracycline use. We compared this calculation to the number of patients with PTCS unrelated to tetracycline use.

RESULTS

Between 2007 and 2014, a total of 960 patients in the University system between the ages of 12 and 50 were prescribed a tetracycline antibiotic. Among those, 45 were diagnosed with tetracycline-induced PTCS. We estimate the incidence of tetracycline-induced PTCS to be 63.9 per 100,000 person-years. By comparison, the incidence of idiopathic intracranial hypertension (IIH) is estimated to be less than one per 100,000 person-years (Calculated Risk Ratio = 178).

CONCLUSIONS

Although a causative link between tetracycline use and pseudotumor cerebri has yet to be firmly established, our study suggests that the incidence of pseudotumor cerebri among tetracycline users is significantly higher than the incidence of IIH in the general population.

Accuracy and reliability of magnetic resonance imaging in the diagnosis of idiopathic intracranial hypertension

PURPOSE

To determine the diagnostic utility of brain magnetic resonance imaging (MRI) findings in patients with idiopathic intracranial hypertension (IIH) and to investigate the significance of evaluating radiological findings together with neurological and ophthalmological data in the diagnosis of IIH.

MATERIALS AND METHODS

All consecutive patients diagnosed with IIH in our tertiary neuro-ophthalmology center between January 1, 2018 and March 15, 2020, were included in the study. The clinical, radiological, and ophthalmological findings of IIH patients were compared with the control group with similar demographic characteristics.

RESULTS

A total of 98 patients, 49 cases and 49 controls, were included in the study. Lateral ventricular index had the highest area under the curve (AUC) value (0.945) for prediction of disease group followed by sella height category (AUC = 0.915) and optic nerve tortuosity (AUC = 0.855) According to the multivariate model we developed, caudate index (OR = 0.572, 95% CI 0.329-0.996), lateral ventricle index (OR = 3.969, 95% CI 1.851-8.509) and bilateral optic nerve tortuosity (OR = 22,784, 95% CI 2.432-213.450) were significant predictors for disease group.

CONCLUSION

Tortuosity in the optic nerve, lateral ventricular index and caudate index can be used as MRI parameters supporting the diagnosis of IIH in clinically suspicious cases. A holistic approach to the clinical and radiological findings of the cases in the diagnosis of IIH can prevent overdiagnosis and enable early correct diagnosis.

Transcriptional profiling of transport mechanisms and regulatory pathways in rat choroid plexus

BACKGROUND

Dysregulation of brain fluid homeostasis associates with brain pathologies in which fluid accumulation leads to elevated intracranial pressure. Surgical intervention remains standard care, since specific and efficient pharmacological treatment options are limited for pathologies with disturbed brain fluid homeostasis. Such lack of therapeutic targets originates, in part, from the incomplete map of the molecular mechanisms underlying cerebrospinal fluid (CSF) secretion by the choroid plexus.

METHODS

The transcriptomic profile of rat choroid plexus was generated by RNA Sequencing (RNAseq) of whole tissue and epithelial cells captured by fluorescence-activated cell sorting (FACS), and compared to proximal tubules. The bioinformatic analysis comprised mapping to reference genome followed by filtering for type, location, and association with alias and protein function. The transporters and associated regulatory modules were arranged in discovery tables according to their transcriptional abundance and tied together in association network analysis.

RESULTS

The transcriptomic profile of choroid plexus displays high similarity between sex and species (human, rat, and mouse) and lesser similarity to another high-capacity fluid-transporting epithelium, the proximal tubules. The discovery tables provide lists of transport mechanisms that could participate in CSF secretion and suggest regulatory candidates.

CONCLUSIONS

With quantification of the transport protein transcript abundance in choroid plexus and their potentially linked regulatory modules, we envision a molecular tool to devise rational hypotheses regarding future delineation of choroidal transport proteins involved in CSF secretion and their regulation. Our vision is to obtain future pharmaceutical targets towards modulation of CSF production in pathologies involving disturbed brain water dynamics.

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

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

Pseudotumor cerebri due to Phenytoin in a child

Pseudotumor cerebri is a manifestation of intracranial hypertension in an otherwise normal individual. We hereby report phenytoin induced pseudotumor cerebri in a nine-year-old boy who received the same as a prophylactic anticonvulsant following surgical removal of unifocal Langerhans cell histiocytosis involving the right frontal bone. The child was evaluated for headache and diplopia after starting phenytoin and on evaluation was found to have bilateral sixth nerve palsy. The only abnormality detected was an elevated cerebrospinal fluid pressure. Withdrawal of phenytoin resulted in complete resolution of symptoms. Despite meticulous literature search, we came across only one other report of phenytoin induced pseudotumor cerebri. We report this case to highlight the need to consider this entity whenever a patient presents with new onset or persistent headache and visual symptoms soon after starting a medication since a high degree of suspicion is needed to arrive at the diagnosis and to take appropriate steps before it progresses to very harmful complications like vision loss.

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

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

[Idiopathic intracranial hypertension (case study)]

Idiopathic intracranial hypertension (IIH) is a rare pathological condition that without proper therapy often results in permanent vision loss. Diagnosis of IIH is often difficult, since it is characterized by a combination of numerous specific and non-specific ophthalmological and neurological criteria. Difficulties in diagnosis significantly delay the prescription of treatment, which affects the visual prognosis. The description of this clinical case is intended to present our own experience in the diagnosis and management tactics of a patient with this pathology, which will be useful for practicing ophthalmologists.

OCT Based Interpretation of the Optic Nerve Head Anatomy and Prevalence of Optic Disc Drusen in Patients with Idiopathic Intracranial Hypertension (IIH)

We aimed to systematically examine the optic nerve head anatomy in patients with idiopathic intracranial hypertension (IIH) using a standardized optical coherence tomography (OCT) protocol. The study retrospectively included 32 patients diagnosed from 2014 to 2021 with IIH. Using OCT, in accordance with a standardized scanning protocol for patients with optic disc drusen, the presence of optic disc drusen, prelaminar hyperreflective lines, peripapillary hyperreflective ovoid mass-like structures, the retinal nerve fiber layer thickness, and macular ganglion cell layer volume was obtained. Optic disc drusen were found in 3.1%, hyperreflective lines in 31.3%, and peripapillary hyperreflective ovoid mass-like structures in 81.3% of all IIH patients at least three months after the time of diagnosis. We found no significant differences in retinal nerve fiber layer thickness or macular ganglion cell layer volume in patients with hyperreflective lines or PHOMS respectively compared to patients without hyperreflective lines (p = 0.1285 and p = 0.1835). In conclusion, the prevalence of optic disc drusen in IIH patients is similar to the reported prevalence in the general population. The high prevalence of hyperreflective lines and peripapillary hyperreflective ovoid mass-like structures in IIH patients suggest these structures be a result of crowding in the optic nerve head caused by papilledema.

Pseudotumor Cerebri with Blindness

Pseudotumor cerebri, or idiopathic intracranial hypertension (IIH), is a syndrome of elevated intracranial pressure (ICP) of unknown etiology that occurs predominantly in obese women of childbearing age. Pseudotumor cerebri literally means "false brain tumor". It is a "diagnosis of exclusion" therefore a complete work-up to rule out life-threatening causes for increased ICP must be performed through a comprehensive history, complete physical examination, diagnostic imaging, and cerebrospinal fluid (CSF) analysis before the diagnosis can be made. The authors present the case of a young woman with headache, and near blindness due to pseudotumor cerebri. The presentation, diagnosis, and treatment options are discussed.

Pseudotumor cerebri syndrome in a child with Alagille syndrome: intracranial pressure dynamics and treatment outcome after ventriculoperitoneal shunting

Alagille syndrome (AS) is a rare multisystem disease of the liver, heart, eyes, face, skeleton, kidneys, and vascular system. The occurrence of pseudotumor cerebri syndrome (PTCS) in patients with AS has been reported only exceptionally. Owning to its rarity and a mostly atypical presentation, the diagnosis and natural history of affected patients remain uncertain. We report an atypical case of PTCS in a 4-year-old boy with a known history of AS who presented with bilateral papilledema (PE) on a routine ophthalmological examination. Visual findings deteriorated after treatment with acetazolamide. Continuous intracranial pressure (ICP) monitoring was then utilized to investigate ICP dynamics. Successful treatment with resolution of PE was achieved after ventriculoperitoneal shunting but relapsed due to growth-related dislocation of the ventricular catheter. This report brings new insights into the ICP dynamics and the resulting treatment in this possibly underdiagnosed subgroup of PTCS patients. It also demonstrates that ventriculoperitoneal shunting can provide long-term improvement of symptoms for more than 10 years.

A Comparison Between the Clinical Features of Pseudotumor Cerebri Secondary to Tetracyclines and Idiopathic Intracranial Hypertension

PURPOSE

Comparisons between clinical features of tetracycline-induced pseudotumor cerebri (PTC-T) and those of idiopathic intracranial hypertension (IIH) are absent in the literature. We hypothesized that significant clinical differences between these etiologies exist and could be better understood by retrospective analysis.

DESIGN

Retrospective cohort study.

METHODS

We reviewed patients diagnosed with pseudotumor cerebri syndrome (PTCS) at our center and identified those who developed PTC-T after treatment with a tetracycline-class antibiotic and those with IIH. Groups were compared by demographics, body mass index, ophthalmic examination, treatment, clinical course, and visual outcomes.

RESULTS

We identified 52 cases of PTC-T and 302 cases of IIH. Obesity rates were significantly different (43.8% for PTC-T vs 79.2% for IIH, P < .001). The mean age at diagnosis was younger for PTC-T (19.8 years vs 28.1 years for IIH, P < .001). Diplopia was more common with PTC-T (40.4% vs 20.1% for IIH, P = .001). The mean illness duration was shorter for PTC-T (18.3 weeks vs 62.9 weeks for IIH, P <.0001). Recurrence rates were significantly different (4.0% for PTC-T vs 16.5% for IIH, P <.001). The frequency of surgical intervention was similar. Vision loss was uncommon but occurred with similar frequency.

CONCLUSION

We identified significant clinical differences but also identified important similarities between the 2 groups. There appear to be nonobese patients who develop PTC-T, discontinue the antibiotic, and never develop PTCS again. There are other patients who develop PTC-T, discontinue the antibiotic, and later develop IIH. We conclude that PTC-T represents a spectrum of disease in susceptible individuals.

The effect of intracerebral structure volumes on idiopathic intracranial hypertension

BACKGROUND

This aim of this study was to assess the effect of idiopathic intracranial hypertension (IIH) in the development of intracranial hypertension by measuring patients' cerebrospinal fluid (CSF), brain, and segment volumes. IIH is a disease of unknown cause characterized by chronic CSF pressure elevation and papillary edema. Under the Monro-Kellie doctrine, efforts have been made to explain the disease through an increase in the volumes of one or two of brain, blood or CSF in the intracranial cavity, although these have not been completely successful.

METHODS

Twelve IIH patients diagnosed based on the modified Dandy criteria and 15 age- and sex-compatible healthy controls were included in the study. Cases' 3D T1 sequence images were evaluated using the voxel-based volumetric analysis system (volBrain). Intracranial cavity extraction, macrostructures, and subcortical structure volumes were measured and compared.

RESULTS

No statistically significant differences were observed between control cases' and IIH patients' CSF, cerebrum, cerebellum, brainstem, and subcortical structure volumes.

CONCLUSION

IIH arises from a chronic cause that does not impair the volumetric balance between structures inside the intracerebral cavity.

Quantitative magnetic resonance image assessment of the optic nerve and surrounding sheath after spaceflight

A subset of long-duration spaceflight astronauts have experienced ophthalmic abnormalities, collectively termed spaceflight-associated neuro-ocular syndrome (SANS). Little is understood about the pathophysiology of SANS; however, microgravity-induced alterations in intracranial pressure (ICP) due to headward fluid shifts is the primary hypothesized contributor. In particular, potential changes in optic nerve (ON) tortuosity and ON sheath (ONS) distension may indicate altered cerebrospinal fluid dynamics during weightlessness. The present longitudinal study aims to provide a quantitative analysis of ON and ONS cross-sectional areas, and ON deviation, an indication of tortuosity, before and after spaceflight. Ten astronauts undergoing ~6-month missions on the International Space Station (ISS) underwent high-resolution magnetic resonance imaging (MRI) preflight and at five recovery time points extending to 1 year after return from the ISS. The mean changes in ON deviation, ON cross-sectional area, and ONS cross-sectional area immediately post flight were −0.14 mm (95% CI: −0.36 to 0.08, Bonferroni-adjusted P = 1.00), 0.13 mm² (95% CI −0.66 to 0.91, Bonferroni-adjusted P = 1.00), and −0.22 mm² (95% CI: −1.78 to 1.34, Bonferroni-adjusted P = 1.00), respectively, and remained consistent during the recovery period. Terrestrially, ONS distension is associated with increased ICP; therefore, these results suggest that, on average, ICP was not pathologically elevated immediately after spaceflight. However, a subject diagnosed with optic disc edema (Frisen Grade 1, right eye) displayed increased ONS area post flight, although this increase is relatively small compared to clinical populations with increased ICP. Advanced quantitative MRI-based assessment of the ON and ONS could help our understanding of SANS and the role of ICP.

Pseudotumor cerebri-Case report

An 46-year-old Caucasian woman was diagnosed with idiopathic intracranial hypertension (IIH) after presenting with papilledema and bilateral visual blurring. Lumbar puncture revealed an opening pressure of more than 550 mmH2O. Cerebral magnetic resonance imaging (MRI) showed bilateral flattening of the posterior sclera, enhancement of the prelaminar optic nerve, distension of the perioptic subarachnoid space, intraocular protrusion of the prelaminar optic nerve and empty sella. The main purpose of the treatment was to release the symptoms and preserve the vision. It was initiated the general treatment with Mannitol 20%, 250 ml/day, Acetazolamide 2x500 mg/day and B-vitamins. After discharge the patient followed a treatment with acetazolamide 2x250 mg/ daily doses and oral potassium supplements 30 mg bid/day. Key words: pseudotumor cerebri, idiopatic intracranial hypertension, papilledema,

Identification of a previously unreported co-crystal form of acetazolamide: a combination of multiple experimental and virtual screening methods

In this work, we demonstrate an approach of trying multiple methods in a more comprehensive search for co-crystals of acetazolamide.

Case Report: Intracranial Hypertension Secondary to Guillain-Barre Syndrome

Guillain-Barre Syndrome (GBS), a common cause of acute flaccid paralysis, is characterized by a rapidly progressive, usually symmetric weakness of the extremities. Headache and intracranial hypertension (ICHT) are very rare complications of GBS. Herein we report our current case of an obese girl with typical signs of GBS associated with autonomic dysfunction, cranial nerve deficits and increased intracranial pressure (ICP). We also perform a systematic study presenting and discussing previous case reports of GBS associated with ICHT, papilledema or hydrocephalus, highlighting the differences of the current case compared to previous studies. Although intracranial hypertension is a rare complication of pediatric GBS, clinicians should promptly detect it. Obesity may be a predisposing factor, given the strong association between idiopathic intracranial hypertension (IIH) and weight gain. Neurological evaluation, fundus examination and low threshold for intracranial imaging should be an integral part of medical practice in case of obesity, headache or visual changes in GBS patients.

Approach to Slitlike Ventricles: Parietal-Occipital versus Frontal Burr Catheter Entry Sites

BACKGROUND

Slit ventricles can be a challenging target during shunt catheter insertion. Traditionally, the frontal approach has been considered optimal for small ventricles. At this center, routine use of electromagnetic (EM) stereotactic guidance (Stealth, Medtronic, Dublin, Ireland) has enabled a parietooccipital (P-O) burr hole approach to the frontal horns. We compare shunt placement and revisions required for patients with slit ventricles who had shunts inserted via a P-O approach versus frontal shunt.

METHODS

We studied a retrospective cohort of patients with slit ventricles and a ventricular shunt inserted using EM guidance between 2012 and 2018. Slitlike ventricles were defined as the widest point of the lateral ventricle <3 mm. Outcome measures included placement accuracy and survival using the Kaplan-Meier curve. Optimal final catheter tip location was considered to be the frontal horn of the ipsilateral lateral ventricle.

RESULTS

Eighty-two patients (77 female, 5 male) aged 34.9 ± 10.8 years (mean ± standard deviation) had ventricular shunts inserted for idiopathic intracranial hypertension (n = 63), chiari/syrinx (n = 8), congenital (n = 10), and pseudomeningocele (n = 1). Of those identified, 35 had primary P-O shunts and 46 had frontal shunts. Overall, 94% of cases had the catheter tip sitting in the frontal horn. The P-O approach was just as accurate as the frontal approach. Eight P-O shunts and 9 frontal shunts required revision over a 60-month period. There was no significant different in shunt survival between the 2 approaches (P = 0.37).

CONCLUSIONS

EM-guided placement has enabled the P-O approach to be as safe and with equivalent survival to frontal approach. The accuracy of shunt placement between the 2 approaches was similar.

Asymptomatic Versus Symptomatic Idiopathic Intracranial Hypertension in Children

BACKGROUND

Idiopathic intracranial hypertension is a rare neurologic condition characterized by elevated intracranial pressure with normal cerebrospinal fluid analysis and neuroimaging. A subset of pediatric idiopathic intracranial hypertension patients are coincidentally found to have papilledema and elevated intracranial pressure without symptoms (eg, headache, visual blurring, tinnitus). This study aims to investigate the features of asymptomatic pediatric idiopathic intracranial hypertension.

METHODS

Retrospective case-control study of patients aged 0 to 18 years who received idiopathic intracranial hypertension diagnosis from 2005 to 2016. Subjects were included if they met established diagnostic criteria for idiopathic intracranial hypertension diagnosis. Subjects were classified as symptomatic if they presented with 1 symptom related to elevated intracranial pressure, and asymptomatic if no symptoms were present. Statistical analysis was performed to compare the 2 groups.

RESULTS

12 (22.6%) of 53 pediatric idiopathic intracranial hypertension subjects were asymptomatic. Compared to symptomatic idiopathic intracranial hypertension, asymptomatic idiopathic intracranial hypertension had younger age of onset, lower initial opening pressure on lumbar puncture, lower optic nerve edema grades bilaterally, lower likelihood of globe flattening on magnetic resonance imaging (MRI), and smaller required dose of acetazolamide for resolution of papilledema (all P < .05).

CONCLUSION

Asymptomatic idiopathic intracranial hypertension is common among pediatric patients with papilledema and is an important disease entity that requires special clinical management. It may exist as a milder version of idiopathic intracranial hypertension that occurs in younger children, or as a precursor state that later evolves into symptomatic disease.

Postoperative management of patients with spontaneous cerebrospinal fluid leak

PURPOSE OF REVIEW

To explore key management principles and outcomes following surgical intervention for spontaneous CSF leaks of the lateral skull base.

RECENT FINDINGS

Outcomes following surgery for spontaneous CSF leaks of the lateral skull base depend on the surgical approach utilized. The approach reported most frequently in the literature is currently the middle fossa approach. Mean leak recurrence rates, regardless of approach, were approximately 6%. The lowest leak recurrence rates were associated with the combined middle cranial fossa-transmastoid approach. A multilayer closure was employed in all of the reviewed investigations, but the choice of reconstructive material did not significantly affect outcomes. Direct surgical complications rates, overall, were low at less than 2%. Meningitis, intracranial hemorrhage, and perioperative seizure activity were only rarely encountered. A concomitant diagnosis of idiopathic intracranial hypertension was found to be associated with increased rates of leak recurrence and sequential leak development at other skull base sites.

SUMMARY

Postoperative management of patients with spontaneous CSF leaks of the lateral skull base has unique challenges. Observation of key treatment principles can lead to good outcomes and limit morbidity. A high index of suspicion should exist for concomitant idiopathic intracranial hypertension.

Lumbar puncture under fluoroscopy guidance: a technical review for radiologists

There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists. Even within the same institution, there are a variety of preferences among proceduralists with individual perspectives based on the literature, training, and/or experience. Our aim is to provide familiarity with various techniques involved in FG-LP and provide insight on how to improve patient outcomes. The pertinent anatomy and physiology, indications, contraindications, patient management, complications of the procedure, and procedural techniques for performing an FG-LP are reviewed in detail. Potentially controversial topics regarding FG-LP are also addressed. There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists (1). Even within the same institution, there are a variety of individual preferences among physicians with different perspectives based on a combination of literature familiarity, training, and personal experience. Our aim is to provide familiarity with various techniques involved in FG-LP, improve efficiency, and improve patient outcomes. We will also address possible controversial issues regarding FG-LPs using an evidence-based approach.

Idiopathic Intracranial Hypertension: Review of Clinical Syndrome, Imaging Findings, and Treatment

Idiopathic intracranial hypertension (IIH) is a syndrome of unknown cause that is increasing in frequency. Patients who are typically women of childbearing age and obese present with headaches and may also present with visual changes that may become chronic. The purpose of this review is to describe the possible mechanisms for this disease and also to illustrate the ever increasing role of imaging in the diagnosis of this disorder. In addition, the various methods of treatment including medical and surgical will be reviewed. The fact that idiopathic intracranial hypertension has undergone many name changes over the years serves as a reminder that the underlying mechanism is still not well understood. Although there are only several possible mechanisms that can cause increased intracranial pressure, it is still not certain which of these mechanisms is involved. The role of imaging has significantly changed in the evaluation of patients with possible IIH. First, it is involved in ruling out secondary causes of increased intracranial pressure. In addition, there is now ample evidence that the previously held belief that imaging of patients with IIH should be normal is incorrect but rather that there are several subtle findings that radiologists need to look for. These findings include a partially empty sella, flattening of the posterior globe, cupping of optic disks and distension of the optic nerve sheaths. In addition, the role of intracranial venography is playing an ever increasing role due to the finding that a very high percentage of patients have dural venous sinus stenoses. It is becoming clear that there is potentially true morbidity associated with idiopathic intracranial hypertension. The earlier the disease can be diagnosed, the earlier treatment can be started to minimalize permanent visual changes including blindness. Treatment varies from institution to institution due to the fact that multiple specialists with different perspectives treat these patients. Knowledge of subtle imaging features associated with idiopathic intracranial hypertension can help radiologists establish the diagnosis earlier and potentially prevent complications of this disorder. However imaging has not as of yet been shown to be beneficial in managing patients with idiopathic intracranial hypertension.

Idiopathic Intracranial Hypertension in a Mother and Pre-pubertal Twins

Idiopathic intracranial hypertension is a syndrome of elevated intracranial pressure without an identifiable cause. The majority of cases appear to be sporadic, and incidence is highest in obese women of childbearing age. The role of genetics in the pathophysiology of the disease is unclear, and familial cases are rare. We report a familial occurrence in a mother and her twin, 5-year-old sons.

Transverse venous stenting for the treatment of idiopathic intracranial hypertension, or pseudotumor cerebri

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a commonly occurring disease, particularly among young women of child-bearing age. The underlying pathophysiology for this disease has remained largely unclear; however, the recent literature suggests that focal outflow obstruction of the transverse sinus may be the cause. The purpose of this study was to report one group’s early experience with transverse venous sinus stenting in the treatment of IIH and assess its effectiveness.

METHODS

The authors performed a retrospective chart review to identify patients who had undergone stenting of an outflow-obstructed transverse venous sinus for the treatment of IIH at Gates Vascular Institute between January 2015 and November 2017. Patient demographic data of interest included age, sex, BMI, and history of smoking, hypertension, obstructive sleep apnea, hormonal contraceptive use, and acetazolamide therapy. Each patient’s presenting signs and symptoms and whether those symptoms improved with treatment were reviewed. The average opening lumbar puncture (LP) pressure preprocedure, average pressure gradient across the obstructed segment prior to stenting, treatment failure rate (need for shunt placement), and mean follow-up period were calculated.

RESULTS

Of the 18 patients who had undergone transverse venous stenting for IIH, 16 (88.9%) were women. The mean age of all the patients was 38.3 years (median 38 years). Mean BMI was 34.2 kg/m2 (median 33.9 kg/m2). Presenting symptoms were headache (16 patients [88.9%]), visual disturbances (13 patients [72.2%]), papilledema (8 patients [44.4%]), tinnitus (3 patients [16.7%]), and auditory bruit (3 patients [16.7%]). The mean opening LP pressure pre-procedure was 35.6 cm H2O (median 32 cm H2O). The mean pressure gradient measured proximally and distally to the area of focal obstruction within the transverse sinus was 16.5 cm H2O (median 15 cm H2O). Postprocedurally, 14 patients (77.8%) continued to have headaches; 6 (33.3%) continued to have visual disturbances. No patients continued to have auditory bruit (0%) or papilledema (0%). One patient (5.6%) had new-onset tinnitus postprocedure. Overall improvement of symptoms was noted in 16 patients (88.9%) postprocedure, with 1 patient (5.6%) requiring shunt placement and 2 other patients (11.1%) requiring postprocedural LP to monitor intracranial pressure to determine candidacy for further surgical interventions to treat residual symptoms. The mean duration of follow-up was 194.2 days.

CONCLUSIONS

Transverse sinus stenting is a rapidly developing technique that has shown good effectiveness and safety in the literature. Authors of the present study found that stenting a flow-obstructed transverse sinus in patients with IIH was a safe and effective way to treat the condition.

Papilledema: Point-of-Care Ultrasound Diagnosis in the Emergency Department

Point-of-care ultrasound (POCUS) has the potential to diagnose papilledema, a sign of increased intracranial pressure, through optic disc elevation as well as optic nerve sheath diameter measurements. Idiopathic intracranial hypertension (IIH) is a syndrome resulting in increased intracranial pressure. We present a case of IIH where the emergency physician diagnosed papilledema by POCUS via presence of both optic disc elevation and a widened optic nerve sheath diameter.

Venous sinus stenting for reduction of intracranial pressure in IIH: a prospective pilot study

OBJECTIVE

Idiopathic intracranial hypertension (IIH) may cause blindness due to elevated intracranial pressure (ICP). Venous sinus stenosis has been identified in select patients, leading to stenting as a potential treatment, but its effects on global ICP have not been completely defined. The purpose of this pilot study was to assess the effects of venous sinus stenting on ICP in a small group of patients with IIH.

METHODS

Ten patients for whom medical therapy had failed were prospectively followed. Ophthalmological examinations were assessed, and patients with venous sinus stenosis on MR angiography proceeded to catheter angiography, venography with assessment of pressure gradient, and ICP monitoring. Patients with elevated ICP measurements and an elevated pressure gradient across the stenosis were treated with stent placement.

RESULTS

All patients had elevated venous pressure (mean 39.5 ± 14.9 mm Hg), an elevated gradient across the venous sinus stenosis (30.0 ± 13.2 mm Hg), and elevated ICP (42.2 ± 15.9 mm Hg). Following stent placement, all patients had resolution of the stenosis and gradient (1 ± 1 mm Hg). The ICP values showed an immediate decrease (to a mean of 17.0 ± 8.3 mm Hg), and further decreased overnight (to a mean of 8 ± 4.2 mm Hg). All patients had subjective and objective improvement, and all but one improved during follow-up (median 23.4 months; range 15.7–31.6 months). Two patients developed stent-adjacent stenosis; retreatment abolished the stenosis and gradient in both cases. Patients presenting with papilledema had resolution on follow-up funduscopic imaging and optical coherence tomography (OCT) and improvement on visual field testing. Patients presenting with optic atrophy had optic nerve thinning on follow-up OCT, but improved visual fields.

CONCLUSIONS

For selected patients with IIH and venous sinus stenosis with an elevated pressure gradient and elevated ICP, venous sinus stenting results in resolution of the venous pressure gradient, reduction in ICP, and functional, neurological, and ophthalmological improvement. As patients are at risk for stent-adjacent stenosis, further follow-up is necessary to determine long-term outcomes and gain an understanding of venous sinus stenosis as a primary or secondary pathological process behind elevated ICP.

Intracranial Perishunt Catheter Fluid Collections with Edema, a Sign of Shunt Malfunction: Correlation of CT/MRI and Nuclear Medicine Findings

Fluid collections with edema along the intracranial tract of ventriculoperitoneal shunt catheters in adults are rare and are more frequently seen in children. The imaging appearance of these fluid collections is frequently confusing and presents a diagnostic dilemma. We present 6 cases of adult patients noted to have collections with edema along the tract of ventriculoperitoneal shunt catheters. To our knowledge, there are no previous studies correlating the CT/MR imaging findings with nuclear medicine scans in this entity. We hypothesized that when seen in adults, the imaging findings of a CSF-like fluid collection around the intracranial ventriculoperitoneal shunt catheter on CT/MR imaging may suggest areas of CSF accumulation with interstitial edema. It is important to recognize this rare ventriculoperitoneal shunt complication in adults to prevent misdiagnosis of an abscess or cystic tumor.

Efficacy and safety of optic nerve sheath fenestration in patients with raised intracranial pressure

Objective:

To evaluate the efficacy and safety of Optic Nerve Sheath Fenestration (ONSF) in patients with raised intracranial pressure (ICP).

Methods:

This Quasi Experimental Study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi from July 2013 to July 2015. Thirty one eyes of 18 patients who underwent ONSF for raised ICP were followed up for one year to ascertain efficacy and safety of ONSF procedure.

Results:

Thirteen (72.22%) patients underwent ONSF bilaterally, while five (27.78%) underwent unilateral ONSF. Best corrected visual acuity (BCVA) improved in 24 (77.4%), remained stable in four (12.9%) and deteriorated in three (9.7%) patients. Papilledema improved in 27 (87.1%) while remained stable in four (12.9%) according to Frisénscale of Papilledema. Change in BCVA and papilledema from pre-operative values was statistically significant (p<0.001). There was significant negative correlation (r= -0.434, p=.017) between duration of symptoms before presentation and improvement in BCVA. Common complications were a tonic pupil, subconjunctival haemorrhage, chemosis, weakness of recti and diplopia.

Conclusion:

ONSF is an effective procedure with statistically significant improvement in BCVA and reduction in severity of papilledema.

Idiopathic intracranial hypertension: Contemporary review and implications for the otolaryngologist

OBJECTIVES

1) Review controversies pertaining to the pathophysiology, diagnosis, and treatment of idiopathic intracranial hypertension. 2) Discuss the evolving role of otolaryngologists in managing this disease and related disorders.

DATA SOURCES

Primary literature review, Centers for Disease Control and Prevention website, International Classification of Headache Disorders, Second Edition.

METHODS

A comprehensive review of the primary literature was performed from 1990 to 2016 utilizing keywords idiopathic intracranial hypertension, pseudotumor cerebri, benign intracranial hypertension, spontaneous cerebrospinal fluid leak, and encephalocele. Articles were included at the discretion of the authors based on novel and/or historical contributions to the literature.

RESULTS

The incidence of idiopathic intracranial hypertension is increasing along with the obesity epidemic. Undiagnosed patients may present to otolaryngologists with pulsatile tinnitus, dizziness, sleep apnea, and spontaneous cerebrospinal fluid leaks. Although diagnosis is predicated upon imaging findings and lumbar puncture, radiographic signs including empty sella, optic nerve dilation, and globe flattening may suggest the diagnosis. The most effective intervention is weight loss combined with acetazolamide. Surgery is reserved for severe or refractory symptoms and can be highly morbid. Otolaryngologists are increasingly responsible for managing a number of secondary disorders including cerebrospinal fluid rhinorrhea and otorrhea. Failure to manage intracranial hypertension may lead to adverse surgical outcomes.

CONCLUSIONS

The knowledge base for idiopathic intracranial hypertension has greatly expanded over the past 25 years. This disease is associated with a number of conditions directly relevant to otolaryngologists. A keen understanding of this disorder and its management may optimize outcomes in a growing number of patients. Laryngoscope, 128:248-256, 2018.

Idiopathic Intracranial Hypertension in Monozygotic Female Twins: Intracranial Pressure Dynamics and Treatment Outcome

BACKGROUND

Familial cases of idiopathic intracranial hypertension (IIH) are exceedingly rare, and its occurrence in monozygotic twins has not been reported previously.

CASE DESCRIPTION

We report monozygotic female twins who developed IIH, one at age 25 years and the other at age 28 years. Continuous intracranial pressure (ICP) monitoring confirmed elevated ICP as measured initially by lumbar puncture. In both cases, successful treatment with resolution of papilledema and symptoms relief was achieved after ventriculoperitoneal shunting.

CONCLUSIONS

This report documents the first case of IIH in monozygotic twins and the associated changes in ICP dynamics. Interestingly, almost equivalent alterations in ICP dynamics were found in the 2 patients.

Spontaneous cerebrospinal fluid leaks in the anterior skull base secondary to idiopathic intracranial hypertension

Spontaneous cerebrospinal fluid (CSF) leaks represent a clinical entity in which CSF rhinorrhea occurs in the absence of any inciting event. Spontaneous CSF leaks are associated with elevated intracranial pressure (ICP) or have underlying idiopathic intracranial hypertension (IIH). We report a cohort of patients who have undergone nasal endoscopic repair for spontaneous CSF leaks. We review our perioperative complications and the effectiveness of the nasal endoscopic approach to repair spontaneous CSF leaks. Also, we examine the evidence correlating spontaneous CSF leaks and IIH and the role of decreasing ICP in the treatment of nasal spontaneous CSF leaks. A retrospective analysis of patients with nasal spontaneous cerebrospinal fluid leaks was performed. Data on the nature of presentation, patient body mass index, defect location and size, ICP, clinical follow-up, and complications were collected. Thirty-five patients had nasal spontaneous cerebrospinal fluid leaks with evidence of IIH's symptoms. The most common sites were the cribriform plate, the ethmoid roof, and sphenoid lateral pterygoid recess. All patients underwent endonasal endoscopic surgery to repair the defect. Postoperatively, all patients underwent lumbar drainage and acetazolamide therapy. Nasal spontaneous cerebrospinal fluid leaks represent a surgical challenge because of their high recurrence rates. The most important factor for obtaining a successful repair in these patients is reducing their intracranial pressure through nutritional, medical, or surgical means.

Venous sinus stenting in idiopathic intracranial hypertension: a safer surgical approach?

PURPOSE OF REVIEW

The purpose is to summarize treatment strategies in idiopathic intracranial hypertension (IIH), a potentially sight-threatening disease, with a focus on the most current outcome data for venous sinus stenting.

RECENT FINDINGS

Historically, the primary treatment options for medically refractory IIH consisted of either optic nerve sheath fenestration or cerebrospinal fluid diversion procedures. The visual outcomes of these procedures are favorable, though they tend to be associated with a high rate of complication and failure. Recent trials suggest that venous sinus stenting offers both comparable rates of efficacy - with improved papilledema in 97% of patients, resolved headache in 83%, and improved visual acuity in 78% - and improved safety and reliability relative to older surgical techniques.

SUMMARY

Patients whose sight is threatened by medically refractory IIH must often consider invasive procedures to control their disease. Venous sinus stenting may offer equal efficacy and lower failure and complication rates than traditional surgical approaches such as optic nerve sheath fenestration and cerebrospinal fluid diversion.