What Do Transgender Patients Teach Us About Idiopathic Intracranial Hypertension?

The Pseudotumor Cerebri Syndrome

Pseudotumor cerebri syndrome is a syndrome of increased cerebrospinal fluid pressure without ventriculomegaly, mass lesion, or meningeal abnormality. It is either primary (idiopathic intracranial hypertension, IIH) or secondary. A secondary cause is unlikely when adhering to the diagnostic criteria. Permanent visual loss occurs if undetected or untreated, and the associated headaches may be debilitating. Fulminant disease may result in blindness despite aggressive treatment. This study addresses the diagnosis and management of IIH including new insights into the pathobiology of IIH, updates in therapeutics and causes of overdiagnosis.

Understanding the pathophysiology of idiopathic intracranial hypertension (IIH): a review of recent developments

Idiopathic intracranial hypertension (IIH) is a condition of significant morbidity and rising prevalence. It typically affects young people living with obesity, mostly women of reproductive age, and can present with headaches, visual abnormalities, tinnitus and cognitive dysfunction. Raised intracranial pressure without a secondary identified cause remains a key diagnostic feature of this condition, however, the underlying pathophysiological mechanisms that drive this increase are poorly understood. Previous theories have focused on cerebrospinal fluid (CSF) hypersecretion or impaired reabsorption, however, the recent characterisation of the glymphatic system in many other neurological conditions necessitates a re-evaluation of these hypotheses. Further, the impact of metabolic dysfunction and hormonal dysregulation in this population group must also be considered. Given the emerging evidence, it is likely that IIH is triggered by the interaction of multiple aetiological factors that ultimately results in the disruption of CSF dynamics. This review aims to provide a comprehensive update on the current theories regarding the pathogenesis of IIH.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Idiopathic intracranial hypertension: a step change in understanding the disease mechanisms

The understanding of idiopathic intracranial hypertension (IIH) has evolved over the past few years. Previously, IIH was considered a disease exclusively affecting the neuro-ophthalmic axis, characterized by raised intracranial pressure, headache and papilloedema, and resulting in the risk of severe and permanent visual loss and life-changing disabling headaches. Recent advances have begun to redefine IIH as a probable metabolic disease involving a range of systemic manifestations. More than 95% of individuals affected by the disease are women of reproductive age with obesity. The incidence is rapidly rising and parallels the escalating worldwide obesity rates. Contemporary insights identify associations with insulin resistance, type 2 diabetes and a twofold increased risk of cardiovascular disease in excess of that driven by obesity alone. Adipose distribution in people with IIH, like that in other metabolic diseases, is preferentially centripetal and is associated with changes in intracranial pressure. Evidence now demonstrates adipose tissue dysfunction in people with IIH, involving transcriptional and metabolic priming for lipogenesis and weight gain. Hormonal perturbations are also observed, including a unique phenotype of androgen excess that promotes cerebrospinal fluid secretion. Knowledge of these additional disease features is driving research into novel therapeutic targets and altering the approach to multidisciplinary care.

Idiopathic Intracranial Hypertension in Female-to-Male Transgender Patients on Exogenous Testosterone Therapy

PURPOSE

To present four female-to-male (FTM) transgender patients on testosterone therapy diagnosed with idiopathic intracranial hypertension (IIH).

METHODS

The authors report 4 consecutive FTM transgender patients on exogenous testosterone diagnosed with IIH at a single institution.

RESULTS

Patient 1 presented with progressive blurred vision and a central scotoma 10 weeks after starting testosterone cypionate injections for hormonal gender transition. Bilateral grade 5 papilledema was present; the patient underwent bilateral optic nerve sheath fenestration with improved vision and resolution of edema. Patient 2 presented with transient vision loss, pulsatile tinnitus, and blurred vision 13 months after starting testosterone cypionate injections. The patient had grade 4 and 3 disc edema of the right and left eyes, respectively. Patient 3 presented with headaches and pulsatile tinnitus and was on testosterone injections at an unknown dose. The examination revealed grade 1 and 2 disc edema of the right and left eyes, respectively. Patient 4 presented with decreased vision, transient visual obscurations, and daily migraines while using topical testosterone gel every other day. Color vision was reduced, and lumbar puncture revealed elevated intracranial pressure. All patients had neuroimaging findings consistent with increased intracranial pressure.

CONCLUSIONS

Testosterone therapy plays an essential role in FTM hormonal transitioning and may play a role in IIH. Patients undergoing testosterone therapy for gender transition should be informed of the possibility of developing IIH while on treatment, with obesity possibly increasing this risk. Comprehensive eye examinations should be considered in these patients before initiating hormone therapy.

Guidelines of the International Headache Society for Controlled Clinical Trials in Idiopathic Intracranial Hypertension

The quality of clinical trials is essential to advance treatment, inform regulatory decisions and meta-analysis. With the increased incidence of idiopathic intracranial hypertension and the emergence of clinical trials for novel therapies in this condition, the International Headache Society Guidelines for Controlled Clinical Trials in Idiopathic Intracranial Hypertension aims to establish guidelines for designing state-of-the-art controlled clinical trials for idiopathic intracranial hypertension.

Current and emerging diagnostic and management approaches for idiopathic intracranial hypertension

INTRODUCTION

Idiopathic intracranial hypertension is characterized by raised intracranial pressure that triggers disabling headaches and can cause permanent visual loss. There is an increased incidence and prevalence of the condition linked to location-specific obesity rates. There are no licensed treatments for the condition. The majority of approaches to managing the disease prioritize resolution of papilledema. However, evidence is emerging that idiopathic intracranial hypertension is a systemic metabolic disease.

AREAS COVERED

The aim of this review is to present the emerging pathophysiology evidence which is leading to novel targeted therapeutics. The diagnostic pathway is outlined. The current and potential management approaches for idiopathic intracranial hypertension are also discussed.

EXPERT OPINION

Idiopathic intracranial hypertension is a condition with metabolic dysregulation with systemic manifestations that are present over and above what can be expl.ained by obesity alone. While most of the current management of this condition focuses on the eyes, future management needs to address the disabling headaches and the systemic risks of preeclampsia, gestational diabetes, and major cardiovascular events.

Intracranial Hypertension Associated With Testosterone Therapy In Female-To-Male Transgender Patients: A Case Report And Literature Review

We highlight a case of intracranial hypertension secondary to exogenous testosterone in a female-to-male transgender patient and present a systematic review of similar cases. Our review identified 19 female-to-male transgender individuals with intracranial hypertension. The mean age was 24.2 years and most common presenting symptom was headache (78.9% of patients). The most frequently associated ocular symptoms were transient visual obscurations (42.1%) and blurred vision (21.1%). Onset of symptoms occurred concurrently with exogenous testosterone therapy in 89.5% of the patients. The most common treatments were acetazolamide (89.5%), topiramate (31.6%), and alteration in hormone regimen (21.1%); four cases required surgery. These findings aid clinicians treating intracranial hypertension in patients undergoing gender affirmation therapy in a conscientious, patient-centered manner.

Association of Amount of Weight Lost After Bariatric Surgery With Intracranial Pressure in Women With Idiopathic Intracranial Hypertension

BACKGROUND AND OBJECTIVES

The idiopathic intracranial hypertension randomized controlled weight trial (IIH:WT) established that weight loss through bariatric surgery significantly reduced intracranial pressure when compared with a community weight management intervention. This substudy aimed to evaluate the amount of weight loss required to reduce intracranial pressure and to explore the effect of different bariatric surgical approaches.

METHODS

IIH:WT was a multicenter randomized controlled trial. Adult women with active idiopathic intracranial hypertension and a body mass index ≥35 kg/m2 were randomized to bariatric surgery or a community weight management intervention (1:1). This per-protocol analysis evaluated the relationship between intracranial pressure, weight loss, and the weight loss methods. A linear hierarchical regression model was used to fit the trial outcomes, adjusted for time, treatment arm, and weight.

RESULTS

Sixty-six women were included, of whom 23 had received bariatric surgery by 12 months; the mean age was 31 (SD 8.7) years in the bariatric surgery group and 33.2 (SD 7.4) years in the dietary group. Baseline weight and intracranial pressure were similar in both groups with a mean weight of 119.5 (SD 24.1) and 117.9 (SD 19.5) kg and mean lumbar puncture opening pressure of 34.4 (SD 6.3) and 34.9 (SD 5.3) cmCSF in the bariatric surgery and dietary groups, respectively. Weight loss was significantly associated with reduction in intracranial pressure (R2 = 0.4734, p ≤ 0.0001). Twenty-four percentage of weight loss (weight loss of 13.3 kg [SD 1.76]) was associated with disease remission (intracranial pressure [ICP] ≤ 25 cmCSF). Roux-en-Y gastric bypass achieved greater, more rapid, and sustained ICP reduction compared with other methods.

DISCUSSION

The greater the weight loss, the greater the reduction in ICP was documented. Twenty four percentage of weight loss was associated with disease remission. Such magnitude of weight loss was unlikely to be achieved without bariatric surgery, and hence, consideration of referral to a bariatric surgery program early for those with active idiopathic intracranial hypertension may be appropriate.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02124486; ISRCTN registry number ISRCTN40152829; doi.org/10.1186/ISRCTN40152829.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that weight loss after bariatric surgery results in reduction in intracranial pressure in adult women with idiopathic intracranial hypertension. This study is Class II because of the use of a per-protocol analysis.

Hypogonadism and Intracranial Hypertension: A Case Report and Brief Review

Intracranial hypertension is rare and there are few cases in men in the literature that report an association between hypogonadism and intracranial hypertension. Herein, we review a diagnosis of hypergonadotropic hypogonadism in the setting of intracranial hypertension. The patient was a 40-year-old male with morbid obesity, hypertension, and prediabetes, with symptoms of hypogonadism, who on further workup was found to have intracranial hypertension. This case report serves to raise awareness of the association between idiopathic intracranial hypertension and hypogonadism in men.

Depression and generalized anxiety symptoms in idiopathic intracranial hypertension: Prevalence, under-reporting and effect on visual outcome

BACKGROUND

Patients with idiopathic intracranial hypertension (IIH) have been reported to have high prevalence of co-existent mood disorders. We investigated the frequency of symptoms of depression and anxiety in a large cohort of patients with IIH without a known psychiatric diagnosis and compared it with the age- and gender-matched control group. We also studied whether the presence and severity of co-existing mood disorder was related to visual outcome in patients with IIH.

METHODS

The Patient Health Questionnaire-8 (PHQ-8) for depression symptoms and the Generalized Anxiety Disorder-7 (GAD-7) questionnaire for symptoms of generalized anxiety were administered via telephone survey to 100 patients with known diagnosis of IIH and 100 control subjects (matched for age and gender) who did not report a history of anxiety or depression during their prior in-person consultations. All participants were also asked whether they had ever been previously diagnosed with a mood disorder during this telephone assessment. Administered questionnaire results were correlated with final visual outcome in IIH cohort.

RESULTS

34 IIH patients and 36 controls self-reported anxiety and/or depression when specifically asked if they had ever been diagnosed with these conditions although this was not reported on clinic intake questionnaires. Mean PHQ-8 depression scale score was 6.5 ± 0.6 in control group and 7.6 ± 0.6 in IIH group (p = 0.18). Mean GAD-7 score was 6.3 ± 0.5 in control group and 7.7 ± 0.6 in the IIH group (p = 0.06). In multivariable regression, scores on both scales were correlated with higher body mass index (BMI), younger age and presence of headache, but not with IIH diagnosis. In the IIH cohort, visual outcomes were not related to GAD-7 or PHQ-8 scores but were predicted by mean deviation on visual fields at presentation.

CONCLUSIONS

Pre-existing diagnosis of anxiety and depression are highly under-reported. Symptoms of anxiety and depression are very common in young women with elevated BMI and headache, however, there was no statistical difference in frequency of these symptoms between IIH and control groups. Presence and severity of mood disorder symptoms did not correlate with the final visual outcome in patients with IIH.

Asymptomatic idiopathic intracranial hypertension post female to male gender transition

A 23- year-man post female to male (FTM) gender transition was found to have bilateral papilloedema at a routine optician visit. The patient was referred on for formal ophthalmological and neurological assessments. Optical coherence tomography (OCT) confirmed the presence of bilateral papilloedema. The patient was entirely asymptomatic and had no medical history. He took testosterone intramuscularly once per month. Neurological examination was otherwise normal. Investigations including routine blood panels, CT brain, MRI brain and cerebral MR venogram were all normal. Lumbar puncture yielded cerebrospinal fluid (CSF) normal in appearance but demonstrated raised intracranial pressure. In the absence of other causative aetiologies a diagnosis of idiopathic intracranial hypertension (IIH) was made. Treatment was commenced with acetazolamide and the patient was discharged with outpatient ophthalmological and neurological follow-up.

Subclinical Signs of Retinal Involvement in Hereditary Angioedema

To explore retinal abnormalities using spectral domain optical coherence tomography (SD-OCT) and OCT-angiography (OCT-A) in a highly selective cohort of patients with type I hereditary angioedema (HAE). This prospective case-control study included 40 type I HAE patients and 40 age-/sex-matched healthy subjects (HC). All participants underwent SD-OCT-scanning of retinal posterior pole (PP), peripapillary retinal nerve fiber layer (pRNFL), and optic nerve head (ONH). Superficial/deep capillary density was analyzed by OCT-A. A total of 80 eyes from 40 HAE and 40 eyes from HC were evaluated. The pRNFL was thicker in HAE than in HC in nasal superior (p < 0.0001) and temporal quadrants (p = 0.0005 left, p = 0.003 right). The ONH thickness in HAE patients was greater than in HC in the nasal (p = 0.008 left, p = 0.01 right), temporal (p = 0.0005 left, p = 0.003 right), temporal inferior (p = 0.007 left, p = 0.0008 right), and global (p = 0.005 left, p = 0.007 right) scans. Compared to HC, HAE showed a lower capillary density in both superficial (p = 0.001 left, p = 0.006 right) and deep (p = 0.008 left, p = 0.004 right) whole images, and superficial (p = 0.03 left) and deep parafoveal (p = 0.007 left, p = 0.005 right) areas. Our findings documented subclinical retinal abnormalities in type I HAE, supporting a potential role of the retinal assessment by SD-OCT/OCT-A as a useful tool in the comprehensive care of HAE patients.

Idiopathic intracranial hypertension in a pediatric transgender patient

Purpose

Androgens given for gender affirmation have been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH) in transgender patients. 10 cases of transgender adults with IIH have been published but this association has not been described in younger patients. Herein we describe the first case of IIH in an adolescent transgender patient.

Observations

A 17-year-old non-obese female-to-male transgender patient on subcutaneous testosterone since age 13 presented with a two-month history of transient visual obscuration and frontal headaches. Ophthalmological examination revealed Frisen grade 2 papilledema with preserved visual function. Lumbar puncture confirmed elevated opening pressure. Papilledema resolved with oral acetazolamide and reduction of testosterone therapy.

Conclusions and Importance

The use of cross-sex hormone therapy (CSH) for gender affirmation may increase the risk of IIH. Awareness of this association is important as the number of younger transgender patients seeking CSH is increasing significantly.

Headache in transgender and gender-diverse patients: A narrative review

OBJECTIVE

To summarize the unique aspects of managing headache in gender minorities and current research in this area including the potential relationship between gender-affirming hormone therapy (GAHT) and headache.

BACKGROUND

The study of headache in gender minorities is intrinsically important. Gender minorities are medically underserved, and their medical care to date has been limited by socioeconomic disadvantages including stigma and an unsupportive clinical environment. Despite the rising population of transgender and gender-diverse adults and youth, headache research has also been limited. Knowledge of hormonal effects on headache in cisgender patients raises the question of possible effects of GAHT on transgender patients.

METHODS/RESULTS

The manuscript is a narrative review of current best practices in treating transgender patients, including the use of appropriate terminology and ways to create a supportive environment. It also contains current guidelines on GAHT and reviews drug-drug interactions and secondary headache related to hormone therapy. We also review transgender headache research and related research on hormonal effects on headache in cisgender individuals.

CONCLUSION

Creating a supportive environment for transgender and gender-diverse patients and being knowledgeable about GAHT are key to providing quality headache care. This review identifies further research needs for this population including the epidemiology of headache disorders in sexual minorities and the potential effects of GAHT on headache disorders in transgender patients.

Sexual and Gender Minority Health in Neurology: A Scoping Review

Importance

Little is known about the neurologic health needs of sexual and gender minority (SGM) individuals, and existing research indicates health care disparities for this group.

Objective

To describe the current state of science in SGM neurology and highlight areas of knowledge and gaps to guide future research.

Evidence Review

All articles published before April 12, 2020, in PubMed, Embase, Web of Science, PsycInfo, CINAHL, and BIOSIS Previews were searched using a search string encompassing SGM descriptors and neurologic disorders. A total of 8359 items were found and entered into EndNote, and 2921 duplicates were removed. A blind title and abstract review was performed followed by full-text review in duplicate, with conflicts settled through consensus, to identify 348 articles eligible for data abstraction. Articles presenting primary data about an identified adult SGM population addressing a clinical neurology topic were included. Descriptive statistics were used for abstracted variables.

Findings

Of 348 studies, 205 (58.9%) were case reports or series, 252 (72.4%) included sexual minority cisgender men, and 247 (70.9%) focused on HIV. An association was found between autism spectrum disorder and gender dysphoria in 9 of 16 studies (56.3%), and a higher risk of ischemic stroke in transgender women was shown in other studies. Literature in neuroinfectious disease, the most common topic, largely focused on HIV (173 of 200 studies [86.5%]). Findings in other neurologic topics were limited by lack of data.

Conclusions and Relevance

In this rigorous compendium of SGM neurology literature, several deficiencies were found: most studies focused on a limited breadth of neurologic pathology, included only a portion of the overall SGM community, and did not assess other aspects of sociodemographic diversity that may contribute to disparities in health care access and outcomes among SGM individuals. Expanding neurologic research to include broader representation of SGM individuals and incorporating sociodemographic factors, like race/ethnicity and socioeconomic status, are essential steps toward providing equitable neurologic care for this community.

Elevated Intracranial Pressure Associated With Exogenous Hormonal Therapy Used for Gender Affirmation

BACKGROUND

Addison disease, corticosteroid withdrawal, and taking synthetic growth hormone have been linked with development of intracranial hypertension, but there is still debate on whether administration of other exogenous hormones plays a role in precipitating elevated pressure. The growing use of hormonal therapy for gender affirmation provides an opportunity to explore this possibility.

METHODS

All transgender patients taking exogenous hormones for female-to-male (FTM) and male-to-female (MTF) transitions who were diagnosed with intracranial hypertension at Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital and Beth Israel Deaconess Medical Center between August 2014 and November 2018 were included in a retrospective review. Visual acuity, type, and dose of exogenous hormone, visual field testing, clinical exam, results of neuroimaging and lumbar puncture, and treatment modalities were catalogued and analyzed.

RESULTS

Six transgender individuals were identified. Five were FTM, with an average hormone treatment time of 18.4 months, and one was MTF who had been treated with hormones for 4 years. The average age of all patients was 23.5 years. The average time between onset of symptoms and presentation was 5 months. Fifty percent of the patients reported pulse-synchronous tinnitus, 83% reported positional headache, 33% reported transient visual obscurations, and 16% reported diplopia. Lumbar punctures performed on 4 of the patients revealed elevated opening pressures and normal cerebrospinal fluid constituents. MRI findings consistent with elevated intracranial pressure (ICP) were present in the other 2 patients in whom lumbar puncture was unsuccessful. Four patients were treated with acetazolamide and one was treated with topiramate, with an average follow-up time of 15.7 months. All patients demonstrated bilateral optic disc swelling, and all maintained normal acuity and color vision. Performance on visual field testing was not significantly affected in any patient.

CONCLUSIONS

This is the largest reported series to date of gender-transitioning patients with intracranial hypertension, including one novel MTF conversion. These observations warrant further investigation into the possible link of exogenous hormonal therapy and elevated ICP and any mechanisms or confounders underlying this potential association.

New horizons for idiopathic intracranial hypertension: advances and challenges

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is becoming a recognized condition due to the increasing incidence linked to a global obesity epidemic.

SOURCES OF DATA

All English papers on PubMed, Cochrane and Scholar between inception until 1 March 2020 were considered.

AREAS OF AGREEMENT

Studies suggest central adiposity has a pathogenic role. Recent weight gain is a risk factor and weight loss has a key role in management.

AREAS OF CONTROVERSY

Interpretation of abnormal lumbar puncture opening pressure is debated. There is an increasing recognition of obesity stigma and how this should be approached.

GROWING POINTS

Further evidence is required for the choice of surgical intervention for fulminant IIH. Education regarding IIH should be evidence based.

AREAS TIMELY FOR DEVELOPING RESEARCH

Novel research of the pathology of IIH is influencing development of therapies such as glucagon-like peptide-1 receptor agonists and targeting unique androgen signatures. The newly discovered cardiovascular risk requires further attention.

Reviewing the Recent Developments in Idiopathic Intracranial Hypertension

There is increasing evidence and appreciation of idiopathic intracranial hypertension (IIH) in medicine. The pathological processes underlying raised intracranial pressure are being studied, with new insights found in both hormonal dysregulation and the metabolic neuroendocrine axis. These will potentially lead to novel therapeutic targets for IIH. The first consensus guidelines have been published on the investigation and management of adult IIH, and the International Headache Society criteria for headache attributable to IIH have been modified to reflect our evolving understanding of IIH. Randomized clinical trials have been published, and a number of studies in this disease area are ongoing.

Guide to preclinical models used to study the pathophysiology of idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is characterised by raised intracranial pressure (ICP) and papilloedema in the absence of an identifiable secondary cause typically occurring in young women with obesity. The impact is considerable with the potential for blindness, chronic disabling headaches, future risk of cardiovascular disease and marked healthcare utilisation. There have been marked advances in our understanding the pathophysiology of IIH including the role of androgen excess. Insight into pathophysiological underpinnings has arisen from astute clinical observations, studies, and an array of preclinical models. This article summarises the current literature pertaining to the pathophysiology of IIH. The current preclinical models relevant to gaining mechanistic insights into IIH are then discussed. In vitro and in vivo models which study CSF secretion and the effect of potentially pathogenic molecules have started to glean important mechanistic insights. These models are also useful to evaluate novel therapeutic targets to abrogate CSF secretion. Importantly, in vitro CSF secretion assays translate into relevant changes in ICP in vivo. Models of CSF absorption pertinent to IIH, are less well established but highly relevant and of future interest. There is no fully developed in vivo model of IIH but this remains an area of importance. Progress is being made to improve our understanding of the underlying aetiology in IIH including the characterisation of disease biomarkers and their mechanistic role in driving disease pathology. Preclinical models, used to evaluate IIH mechanisms are yielding important mechanistic insights. Further work to refine these techniques will provide translatable insights into disease aetiology.

Emerging themes in idiopathic intracranial hypertension

Purpose

Idiopathic intracranial hypertension (IIH) is a rare disorder characterised by raised intracranial pressure. The underlying pathophysiology is mostly unknown and effective treatment is an unmet clinical need in this disease. This review evaluates key emerging themes regarding disease characteristics, mechanisms contributing to raised intracranial pressure and advances in potential therapeutic targets.

Findings

IIH is becoming more common, with the incidence rising in parallel with the global obesity epidemic. Current medical management remains centred around weight management, which is challenging. Metabolic investigations of patients have identified specific androgen profiles in cerebrospinal fluid (CSF), which suggest an endocrine dysfunction impacting CSF secretion in IIH. Glucagon-like peptide-1 (GLP-1) and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) have been found to play a role in CSF dynamics in IIH and have formed the basis of the first clinical trials looking at new treatments.

Conclusions

Identification of novel molecular targets thought to underlie IIH pathology is now being translated to clinical trials.

Metabolic Concepts in Idiopathic Intracranial Hypertension and Their Potential for Therapeutic Intervention

BACKGROUND

Traditional risk factors associated with idiopathic intracranial hypertension (IIH) include obesity, weight gain, and female sex. The incidence of IIH is increasing and yet the underlying trigger and the fueling pathological mechanisms are still poorly understood.

EVIDENCE ACQUISITION

Review of ophthalmology, neurology, general surgery, obesity, endocrinology, nutrition, and neurosurgery literature was made.

RESULTS

The facts that implicate sex and obesity in IIH and headache are examined. The role of fat distribution in IIH is questioned, and the concept of adipose tissue functioning as an endocrine organ driving IIH is discussed. The impact of androgen metabolism in IIH is reviewed as is the emerging role of glucagon-like-peptide-1 analogues in modulating intracranial pressure. This introduces the concept of developing targeted disease-modifying therapeutic strategies for IIH.

CONCLUSIONS

This review will discuss the possible role of the adipose/gut/brain metabolism axis in IIH and speculate how this may impact the pathogenesis of IIH and therapeutic opportunities.

Eye Conditions in Women

Changes in vision can have significant impact on health and quality of life. Differences between women and men have been identified in the incidence of several eye conditions. Some of these differences are a result of the greater longevity of women. However, the eye, like other organs, is susceptible to the impacts of inflammation and sex steroids. Conditions, such as thyroid eye disease, optic neuritis, and dry eye disease are related to autoimmune or inflammatory conditions and are, thus, more common among women. Idiopathic intracranial hypertension occurs disproportionately in women of childbearing age; the etiology of this condition appears to be related to both inflammatory and sex hormone fluctuations.