New horizons for idiopathic intracranial hypertension: advances and challenges

Risk factors and disease associations in people living with idiopathic intracranial hypertension

INTRODUCTION

Idiopathic intracranial hypertension is a neurological condition characterized by a raised intracranial pressure and papilledema, leading to chronic headaches and visual disturbances. By recognizing modifiable risk factors and deploying evidence-based interventions, healthcare providers have the potential to mitigate the burden of the disease and improve patient outcomes.

AREAS COVERED

It is well known that the condition occurs in predominantly pre-menopausal females who live with obesity particularly in the context of recent weight gain. This review discusses what risk factors may contribute to the metabolic underpinnings of cerebrospinal fluid dysregulation. There are a number of disease associations that are important to screen for as they can alter management.

EXPERT OPINION

There is emerging evidence to suggest that idiopathic intracranial hypertension is a systemic metabolic disease and it is unknown what are all the risk factors are that precipitate the condition. Targeting certain hardwired risk factors is unachievable. However, as recent weight gain has been identified as a predominant risk factor for the development of the disease and relapse, modification of body weight should be the primary aim of management. Insightful research into the involvement of the neuroendocrine axis driving cerebrospinal fluid dysregulation now has the potential for the development of therapeutic targets.

Navigating the Enigma: A Comprehensive Review of Idiopathic Intracranial Hypertension

An unidentified source of increased intracranial pressure is a hallmark of idiopathic intracranial hypertension (IIH), also referred to as pseudotumor cerebri. It mainly affects young, obese women, yet it can happen to anyone, regardless of age, gender, or weight. IIH presents with symptoms such as headaches, visual disturbances, and pulsatile tinnitus and can lead to severe complications, including vision loss, if left untreated. Diagnosis involves clinical evaluation, neuroimaging, and lumbar puncture, while management options include medical interventions and surgical procedures. This review provides a comprehensive overview of IIH, including its etiology, clinical presentation, epidemiology, complications, management approaches, and challenges. Increased awareness among healthcare professionals, standardized diagnostic criteria, and further research efforts are essential for improving outcomes and quality of life for individuals with IIH.

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

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

Weight management communications in idiopathic intracranial hypertension: challenges and recommendations from the patients' perspective

Background

Idiopathic intracranial hypertension (IIH) is a neurometabolic condition severely impacting the quality of life of people living with IIH (PwIIH). Most PwIIH are overweight or live with obesity, and weight loss is recommended by healthcare professionals (HCPs) as it is central to disease management. There is currently no research evaluating patient-clinician interactions when discussing weight management in IIH. The aim of this study was to evaluate the patient experience of communication with HCPs regarding weight management from the perspective of PwIIH.

Methods

A cross-sectional online survey was developed and distributed by the IIH UK charity via their mailing list and social media network. Eligible participants were adults with IIH who have been recommended to lose weight by their HCP. Descriptive statistics were used to summarise quantitative responses and content analysis was used to inductively draw out themes from open-ended free-text responses.

Results

There were 625 respondents. One-fifth of PwIIH (n=127/603, 21%) felt that HCPs were supportive and empathetic about weight management. Five themes were identified on how experiences regarding weight management for IIH can be improved, with PwIIH recommending for HCPs to: (1) detail the relationship between IIH and weight, (2) individualise care, (3) give advice, (4) provide support and (5) adapt communication.

Conclusion

The majority of PwIIH recalled a poor experience and negative emotions when engaged in discussions regarding weight management with their HCPs. Further research should explore the HCPs perspective and evaluate interventions aiming to improve the quality of patient-HCPs communication in IIH.

Longitudinal prospective cohort study evaluating prognosis in idiopathic intracranial hypertension patients with and without comorbid polycystic ovarian syndrome

INTRODUCTION

Idiopathic intracranial hypertension (IIH) and polycystic ovary syndrome (PCOS) are hyperandrogenic metabolic disorders that affect women of reproductive age living with obesity. The previously reported prevalence of comorbid PCOS in IIH patients is highly variable and the longitudinal impact on visual and headache outcomes are unknown.

METHODS

In this prospective longitudinal cohort study patients were identified from the IIH: Life database over a nine-year period (2012-2021). Data collected included demographics and PCOS questionnaire data. Key visual and detailed headache outcomes were recorded. We analysed the key variables for influential outcomes of vision and headache. Logistical regression methods were used to model long term visual and headache outcomes.

RESULTS

Overall 398 women with IIH and documented PCOS questionnaires were followed up for a median of 10 months (range 0-87). Prevalence of PCOS in IIH was 20% (78/398) diagnosed by the Rotterdam criteria. Patients with IIH and comorbid PCOS reported higher self-reported fertility problems (3.2-fold increased risk) and increased need for medical help in becoming pregnant (4.4-fold increased risk). Comorbid PCOS in IIH patients does not adversely impact long-term vision or headache outcomes. The headache burden was high in both cohorts studied.

CONCLUSIONS

The study demonstrated that comorbid PCOS in IIH is common (20%). Diagnosing comorbid PCOS is important as it can impact on fertility and is known to have long-term adverse cardiovascular risks. Our data suggest that a diagnosis of PCOS in those with IIH does not significantly exacerbate long-term vision or headache prognosis.

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.

The Impact of Valsalva Manoeuvres and Exercise on Intracranial Pressure and Cerebrovascular Dynamics in Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a disease characterised by elevated intracranial pressure (ICP). The impact of straining and exercise on ICP regulation is poorly understood yet clinically relevant to IIH patient care. We sought to investigate the impact of Valsalva manoeuvres (VMs) and exercise on ICP and cerebrovascular haemodynamics in IIH. People with IIH were prospectively enrolled and had an intraparenchymal telemetric ICP sensor inserted. Three participants (age [mean ± standard deviation]: 40.3 ± 13.9 years) underwent continuous real-time ICP monitoring coupled with cerebrovascular haemodynamic assessments during VMs and moderate exercise. Participants had IIH with supine ICP measuring 15.3 ± 8.7 mmHg (20.8 ± 11.8 cm cerebrospinal fluid (CSF)) and sitting ICP measuring -4.2 ± 7.9 mmHg (-5.7 ± 10.7 cmCSF). During phase I of a VM ICP increased by 29.4 ± 13.5 mmHg (40.0 ± 18.4 cmCSF) but returned to baseline within 16 seconds from VM onset. The pattern of ICP changes during the VM phases was associated to that of changes in blood pressure, the middle cerebral artery blood velocity and prefrontal cortex haemodynamics. Exercise led to minimal effects on ICP. In conclusion, VM-induced changes in ICP were coupled to cerebrovascular haemodynamics and showed no sustained impact on ICP. Exercise did not lead to prolonged elevation of ICP. Those with IIH experiencing VMs (for example, during exercise and labour) may be reassured at the brief nature of the changes. Future research must look to corroborate the findings in a larger IIH cohort.

Asymptomatic idiopathic intracranial hypertension: Prevalence and prognosis

BACKGROUND

Little is known about the presentation and prognosis of asymptomatic idiopathic intracranial hypertension (IIH). Papilloedema can be found incidentally on routine fundus examination, with many of these patients actually having symptoms on direct questioning. The aim was to evaluate visual and headache outcomes in people with IIH who present with or without symptoms.

METHODS

Prospective observational cohort study, between 2012 and 2021, 343 people with confirmed IIH diagnosis were enrolled in the IIH:Life database. Outcomes such as vision (LogMAR); Humphrey visual field perimetric mean deviation (PMD) and optical coherence tomography (OCT) and headache were evaluated using LOESS (locally weighted scatterplot smoothing) graphs and regression analysis.

RESULTS

One hundred and twenty-one people had incidentally found papilloedema, with 36 people with completely asymptomatic presentations. Those with asymptomatic IIH at diagnosis had similar visual prognosis compared to those with symptomatic disease. Sixty-six percent of the asymptomatic cohort became symptomatic during follow-up, and of these the predominant symptom was headache (96%). Headache frequency during follow-up was lower in the asymptomatic cohort.

CONCLUSIONS

The prognosis of those with IIH who present with or without symptoms is similar.

Defining the Phenotype and Prognosis of People With Idiopathic Intracranial Hypertension After Cerebrospinal Fluid Diversion Surgery

PURPOSE

To characterize the phenotype of patients with idiopathic intracranial hypertension (IIH) who received cerebrospinal (CSF) diversion surgery and to detail the trajectory of recovery.

DESIGN

Prospective cohort registry study.

METHODS

Patients with IIH with sight-threatening papilledema presenting to a single United Kingdom neuroscience center between 2019 and 2021 were included. Outcomes consisted of perimetric mean deviation (PMD) and optical coherence tomography measures of papilledema (retinal nerve fiber layer [RNFL]) and macular ganglion cell layer (GCL) in both eyes. Headache outcomes included monthly headache days (MHD). Logistic regression methods were used to model long-term outcomes.

RESULTS

Fifty-one patients without previous surgical interventions were included (92% female, mean age 28.1 years [SD 8.4], body mass index 37.4 kg/m2 [SD 9.7], mean days of follow-up 330 [SD 209]). Measurements before surgery showed mean PMD -11.4 dB (SD 9.7), RNFL 364 µm (SD 128), Frisén grade papilledema 4.3 (SD 0.9). and MHD 23 (SD 10.6). At 1 month postoperatively, RNFL and PMD had improved by 38% and 4%, respectively. At 4 months postoperatively, papilledema had resolved. GCL declined by 13% over 12 months. MHD reduced by 75% 3 months postoperatively before returning to baseline levels by 12 months. Five patients (9.8%) required revision surgeries.

CONCLUSIONS

Detailed characteristics of patients with sight-threatening IIH who received CSF diversion surgery and their typical postoperative recovery are presented. These parameters should guide physicians as to when patients with IIH may require surgery and enable the early identification of outliers who fail to respond. Papilledema and PMD recovered but GCL atrophy continued for 12 months. The implication of this delayed atrophy is unknown.

The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial

Therapeutics to reduce intracranial pressure are an unmet need. Preclinical data have demonstrated a novel strategy to lower intracranial pressure using glucagon-like peptide-1 (GLP-1) receptor signalling. Here, we translate these findings into patients by conducting a randomized, placebo-controlled, double-blind trial to assess the effect of exenatide, a GLP-1 receptor agonist, on intracranial pressure in idiopathic intracranial hypertension. Telemetric intracranial pressure catheters enabled long-term intracranial pressure monitoring. The trial enrolled adult women with active idiopathic intracranial hypertension (intracranial pressure >25 cmCSF and papilloedema) who receive subcutaneous exenatide or placebo. The three primary outcome measures were intracranial pressure at 2.5 h, 24 h and 12 weeks and alpha set a priori at less than 0.1. Among the 16 women recruited, 15 completed the study (mean age 28 ± 9, body mass index 38.1 ± 6.2 kg/m2, intracranial pressure 30.6 ± 5.1 cmCSF). Exenatide significantly and meaningfully lowered intracranial pressure at 2.5 h -5.7 ± 2.9 cmCSF (P = 0.048); 24 h -6.4 ± 2.9 cmCSF (P = 0.030); and 12 weeks -5.6 ± 3.0 cmCSF (P = 0.058). No serious safety signals were noted. These data provide confidence to proceed to a phase 3 trial in idiopathic intracranial hypertension and highlight the potential to utilize GLP-1 receptor agonist in other conditions characterized by raised intracranial pressure.

Visual Field Pointwise Analysis of the Idiopathic Intracranial Hypertension Weight Trial (IIH:WT)

Purpose

This study was designed to determine if point analysis of the Humphrey visual field (HVF) is an effective outcome measure for people with idiopathic intracranial hypertension (IIH) compared with mean deviation (MD).

Methods

Using the IIH Weight Trial data, we performed a pointwise analysis of the numerical retinal sensitivity. We then defined a medically treated cohort as having MDs between -2 dB and -7 dB and calculated the number of points that would have the ability to change by 7 dB.

Results

The HVF 24-2 mean ± SD MD in the worse eye was -3.5 ± 1.1 dB (range, -2.0 to -6.4 dB). Total deviation demonstrated a preference for the peripheral and blind spot locations to be affected. Points between 0 dB and -10 dB demonstrated negligible ability to improve, compared with those between -10 dB and -25 dB. For the evaluation of the feasibility for a potential medical intervention trial, only 346 points were available for analysis between -10 dB and -25 dB bilaterally, compared with 4123 points in baseline sensitivities of 0 to -10 dB.

Conclusions

Patients with IIH have mildly affected baseline sensitivities in the visual field based on HVF analyzer findings, and the majority of points do not show substantial change over 24 months in the setting of a randomized clinical trial. Most patients with IIH who are eligible for a medical treatment trial generally have the mildest affected baseline sensitivities. In such patients, pointwise analysis offers no advantage over MD in detection of visual field change.

Disease Course and Long-term Outcomes in Pregnant Women With Idiopathic Intracranial Hypertension: The IIH Prospective Maternal Health Study

BACKGROUND AND OBJECTIVES

Idiopathic intracranial hypertension (IIH) most typically occurs in women of childbearing age with increased weight as a key risk factor for development or exacerbation of the disease. Pregnancy is common in this group of patients. The longer-term effect of pregnancy on IIH has not been established and was the aim of this study.

METHODS

A prospective cohort study (IIH Life) recruited consecutive patients with IIH between 2012 and 2021 and evaluated outcomes including vision (logarithm of the minimum angle of resolution visual acuity, Humphrey visual field perimetric mean deviation, and optical coherence tomography [OCT] imaging) and headache. Four cohorts were evaluated: those with IIH diagnosed for the first time while pregnant, those with established IIH who became pregnant, those with a pregnancy prior to their diagnosis of IIH, and those with IIH who never became pregnant.

RESULTS

Three hundred seventy-seven people with IIH agreed to participate in the IIH Life maternal health study. Mean follow-up was 17.5 months (SD 20.5). IIH diagnosed in pregnancy was rare. Patients diagnosed with IIH while pregnant had greater papilledema (mean OCT total retinal thickness +11.59 µm/mo [95% CI 1.25-21.93]), although they had comparable visual field and acuity measures compared with those with established IIH who became pregnant during their disease course (-1.2 µm/mo [95% CI -2.6 to 0.21]). In those with established IIH, pregnancy did not adversely affect visual or headache outcomes over time, and the trajectory was akin to those with IIH who never had a pregnancy. Headache outcomes showed variability reflecting the IIH cohort as a whole.

DISCUSSION

A diagnosis of IIH while pregnant was rare but associated with more severe papilledema. Long-term visual outcomes in IIH were analogous irrespective of the timing of the pregnancy. These data are reassuring; however, close vigilance of IIH clinical features during pregnancy is recommended.

The idiopathic intracranial hypertension prospective cohort study: evaluation of prognostic factors and outcomes

BACKGROUND

There are limited longitudinal data evaluating outcomes in idiopathic intracranial hypertension (IIH). We aimed to evaluate the long-term outcomes in a real-world cohort of patients with IIH and sought to establish the prognostic factors.

METHODS

A longitudinal prospective cohort study was conducted over 9 years (2012-2021). Data included demographics and disease status. All consenting patients with IIH were recruited. Visual outcomes included visual acuity, Humphrey visual field and optical coherence tomography (OCT) imaging measurements. Headache frequency, severity, and impact were noted. We analysed the key variables impacting visual and headache outcomes.

RESULTS

The cohort contained 490 patients with a confirmed IIH diagnosis. 98% were female with a mean body mass index (BMI) of 38 kg/m². Those with the highest OCT retinal nerve fibre layer had the worst visual outcomes. We noted a delayed decline, in the visual field and OCT ganglion cell layer after 12 months. In the medically managed cohort (n = 426), we found that disease duration and change in BMI had the greatest influence on visual outcomes. There was a high burden of headache, with a daily headache at presentation and prior migraine history influencing long-term headache prognosis.

CONCLUSIONS

There is a delayed decline in visual outcomes in those with the most severe papilloedema. Disease duration and change in BMI were the key visual prognostic factors, therefore those with the more acute disease may require closer monitoring. Improving prognosis in IIH should focus on the potentially modifiable factor of weight management.

Depression and anxiety in women with idiopathic intracranial hypertension compared to migraine: A matched controlled cohort study

OBJECTIVE

To evaluate mental health burden in women with idiopathic intracranial hypertension (IIH) compared to matched women with migraine and population controls.

BACKGROUND

Depression and anxiety are recognized comorbid conditions in those with IIH and lead to worse predicted medical outcomes. The mental health burden in IIH has not been previously evaluated in a large, matched cohort study.

METHODS

We performed a population-based matched, retrospective cohort study to explore mental health outcomes (depression and anxiety). We used data from IQVIA Medical Research Data, an anonymized, nationally representative primary care electronic medical records database in the United Kingdom, from January 1, 1995, to September 25, 2019. Women aged ≥16 years were eligible for inclusion. Women with IIH (exposure) were matched by age and body mass index with up to 10 control women without IIH but with migraine (migraine controls), and without IIH or migraine (population controls).

RESULTS

A total of 3411 women with IIH, 30,879 migraine controls and 33,495 population controls were included. Of these, 237, 2372 and 1695 women with IIH, migraine controls and population controls, respectively, developed depression during follow-up, and 179, 1826 and 1197, respectively, developed anxiety. There was a greater hazard of depression and anxiety in IIH compared to population controls (adjusted hazard ratio [aHR] 1.38, 95% confidence interval [CI] 1.20-1.58; and aHR 1.40, 95% CI 1.19-1.64, respectively), while hazards were similar to migraine controls (aHR 0.98, 95% CI 0.86-1.13; and aHR 0.98, 95% CI 0.83-1.14, respectively).

CONCLUSION

Depression and anxiety burden in women with IIH is higher than in the general population, and comparable to that in matched women with migraine. This may indicate that presence of headache is a potential driver for comorbid depression and anxiety in IIH.

Co-morbid Polycystic Ovarian Syndrome with Idiopathic Intracranial Hypertension

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

Idiopathic intracranial hypertension: Evaluation of births and fertility through the Hospital Episode Statistics dataset

OBJECTIVE

Idiopathic intracranial hypertension (IIH) predominantly affects women of reproductive age with obesity, and these women have a distinct profile of hyperandrogenism and insulin resistance. Polycystic ovary syndrome (PCOS) has an established adverse fertility phenotype that typically affects obese women. As IIH may impact reproductive health, we sought to evaluate fertility, gestational complications and pregnancy outcome in IIH.

DESIGN

Prospective cohort study from English Hospital Episode Statistics dataset.

SETTING

English hospitals, UK.

POPULATION

Women aged 18-45 years seen in English hospitals between 1 April 2002 and 31 March 2019. Patients were required to have an IIH diagnosis and were compared with those with PCOS and general population female controls.

MAIN OUTCOME MEASURES

Pregnancies resulting in live births, complications of gestational diabetes and pre-eclampsia, and method of delivery.

RESULTS

Data was collected from 17 587 IIH, 199633 PCOS and 10 947 012 women in the general population. The live birth rate, adjusted for age, was significantly lower among women with IIH (54.1%) than PCOS (67.9%), p < 0.0001 and the general population (57.7%), p < 0.0001. Pre-eclampsia and gestational diabetes risks were higher following a diagnosis of IIH (5.3-fold and 2.7-fold, respectively, p < 0.0001) compared with the general population controls. Following a diagnosis of IIH, elective caesarean section rates were more than twice that of general population (odds ratio [OR] 2.4) and prior to a diagnosis of IIH (OR 2.2).

CONCLUSIONS

These data indicate there are lower age-adjusted total pregnancy rates, increased risk of pre-eclampsia and gestational diabetes, and a doubling of elective caesarean section rates in those with a diagnosis of IIH.

Evaluation of diurnal and postural intracranial pressure employing telemetric monitoring in idiopathic intracranial hypertension

OBJECTIVES

Intracranial pressure (ICP) has been thought to vary diurnally. This study evaluates diurnal ICP measurements and quantifies changes in ICP occurring with changes in body posture in active idiopathic intracranial hypertension (IIH).

METHODS

This prospective observational study utilized telemetric ICP monitoring in people with active IIH. Participants had the Raumedic p-Tel ICP intraparenchymal device (Raumedic, Hembrechts, Germany) surgically inserted. Changes in ICP in the supine position were evaluated. Then, the ICP was measured in the standing, sitting, supine, left lateral decubitus positions and with coughing and bending. Ultimately, changes in ICP over the course of 24 h were recorded. ISRCTN registration number 12678718.

RESULTS

15 women were included, mean (standard deviation) age 29.5 (9.5) years, body mass index 38.1 (6.2) kg/m², and baseline mean ICP of 21.2 (4.8) mmHg (equivalent to 28.8 (6.5) cmCSF). Mean ICP rose with the duration in the supine position 1.2 (3.3) mmHg over 5-minutes (p = 0.175), 3.5 (2.8) mmHg over 30-minutes (p = 0.0002) and by a further 2.1 (2.2) mmHg over 3 h (p = 0.042). Mean ICP decreased by 51% when moving from the supine position to standing (21.2 (4.8) mmHg to 10.3 (3.7) mmHg respectively, p = 0.0001). Mean ICP increased by 13% moving from supine to the left lateral decubitus position (21.2 (4.8) mmHg to 24.0 (3.8) mmHg, p = 0.028). There was no significant difference in ICP measurements at any point during the daytime, or between 5-minute standing or supine recordings and prolonged ambulatory daytime and end of night supine recordings respectively. ICP, following an initial drop, increased progressively in conjunction with lying supine position from 23:00 h to 07:00 h by 34% (5.2 (1.9) mmHg, p = 0.026).

CONCLUSION

This analysis demonstrated that ICP does not appear to have a diurnal variation in IIH, but varies by position and duration in the supine position. ICP rose at night whilst the patient was continuously supine. Furthermore, brief standing and supine ICP measures in the day predicted daytime prolonged ambulatory measures and end of night peak ICP respectively. This knowledge gives reassurance that ICP can be accurately measured and compared at any time of day in an ambulant IIH patient. These are useful findings to inform clinical measurements and in the interpretation of ICP analyses in IIH.

TRIAL REGISTRATION

ISTCRN (12678718).

Nuclear Magnetic Resonance Spectroscopy Metabolomics in Idiopathic Intracranial Hypertension to Identify Markers of Disease and Headache

BACKGROUND AND OBJECTIVE

We evaluated the metabolomic profile in the CSF, serum, and urine of participants with idiopathic intracranial hypertension (IIH) compared with that in controls and measured changes in metabolism associated with clinical markers of disease activity and treatment.

METHODS

A case-control study compared women aged 18-55 years with active IIH (Friedman diagnostic criteria) with a sex-matched, age-matched, and body mass index-matched control group. IIH participants were identified from neurology and ophthalmology clinics from National Health Service hospitals and underwent a prospective intervention to induce disease remission through weight loss with reevaluation at 12 months. Clinical assessments included lumbar puncture, headache, papilledema, and visual measurements. Spectra of the CSF, serum, and urine metabolites were acquired using proton nuclear magnetic resonance spectroscopy.

RESULTS

Urea was lower in IIH participants (CSF, controls median ± IQR 0.196 ± 0.008, IIH 0.058 ± 0.059, p < 0.001; urine, controls 5971.370 ± 3021.831, IIH 4691.363 ± 1955.774, p = 0.009), correlated with ICP (urine p = 0.019) and headache severity (CSF p = 0.031), and increased by 12 months (CSF 12 months; 0.175 ± 0.043, p = 0.004, urine; 5210.874 ± 1825.302, p = 0.043). The lactate:pyruvate ratio was increased in IIH participants compared with that in controls (CSF, controls 49.739 ± 19.523, IIH 113.114 ± 117.298, p = 0.023; serum, controls 38.187 ± 13.392, IIH 54.547 ± 18.471, p = 0.004) and decreased at 12 months (CSF, 113.114 ± 117.298, p < 0.001). Baseline acetate was higher in IIH participants (CSF, controls 0.128 ± 0.041, IIH 0.192 ± 0.151, p = 0.008), correlated with headache severity (p = 0.030) and headache disability (p = 0.003), and was reduced at 12 months (0.160 ± 0.060, p = 0.007). Ketones, 3-hydroxybutyrate and acetoacetate, were altered in the CSF at baseline in IIH participants (3-hydroxybutyrate, controls 0.074 ± 0.063, IIH 0.049 ± 0.055, p = 0.019; acetoacetate, controls 0.013 ± 0.007, IIH 0.017 ± 0.010, p = 0.013) and normalized at 12 months (0.112 ± 0.114, p = 0.019, 0.029 ± 0.017, p = 0.015, respectively).

DISCUSSION

We observed metabolic disturbances that are evident in the CSF, serum, and urine of IIH participants, suggesting global metabolic dysregulation. Altered ketone body metabolites normalized after therapeutic weight loss. CSF:serum urea ratio was altered, which may influence ICP dynamics and headache. Elevated CSF acetate, known to stimulate trigeminal sensitization, was associated with headache morbidity. These alterations of metabolic pathways specific to IIH provide biological insight and warrant mechanistic evaluation.

TRIAL REGISTRATION INFORMATION

Registered on ClinicalTrials.gov, NCT02124486 (submitted April 22, 2014) and NCT02017444 (submitted December 16, 2013).

Increased systemic and adipose 11β-HSD1 activity in idiopathic intracranial hypertension

Context

Idiopathic intracranial hypertension (IIH) is a disease of raised intracranial pressure (ICP) of unknown etiology. Reductions in glucocorticoid metabolism are associated with improvements in IIH disease activity. The basal IIH glucocorticoid metabolism is yet to be assessed.

Objective

The objective of this study was to determine the basal glucocorticoid phenotype in IIH and assess the effects of weight loss on the IIH glucocorticoid phenotype.

Design

A retrospective case-control study and a separate exploratory analysis of a prospective randomized intervention study were carried out.

Methods

The case-control study compared female IIH patients to BMI, age, and sex-matched controls. In the randomized intervention study, different IIH patients were randomized to either a community weight management intervention or bariatric surgery, with patients assessed at baseline and 12 months. Glucocorticoid levels were determined utilizing 24-h urinary steroid profiles alongside the measurement of adipose tissue 11β-HSD1 activity.

Results

Compared to control subjects, patients with active IIH had increased systemic 11β-hydroxysteroid dehydrogenase (11β-HSD1) and 5α-reductase activity. The intervention study demonstrated that weight loss following bariatric surgery reduced systemic 11β-HSD1 and 5α-reductase activity. Reductions in these were associated with reduced ICP. Subcutaneous adipose tissue explants demonstrated elevated 11β-HSD1 activity compared to samples from matched controls.

Conclusion

The study demonstrates that in IIH, there is a phenotype of elevated systemic and adipose 11β-HSD1 activity in excess to that mediated by obesity. Bariatric surgery to induce weight loss was associated with reductions in 11β-HSD1 activity and decreased ICP. These data reflect new insights into the IIH phenotype and further point toward metabolic dysregulation as a feature of IIH.

Cost-effectiveness of bariatric surgery versus community weight management to treat obesity-related idiopathic intracranial hypertension: evidence from a single-payer healthcare system

BACKGROUND

Idiopathic intracranial hypertension (IIH) is associated with significant morbidity, predominantly affecting women of childbearing age living with obesity. Weight loss has demonstrated successful disease-modifying effects; however, the long-term cost-effectiveness of weight loss interventions for the treatment of IIH has not yet been established.

OBJECTIVES

To estimate the cost-effectiveness of weight-loss treatments for IIH.

SETTING

Single-payer healthcare system (National Health Service, England).

METHODS

A Markov model was developed comparing bariatric surgery with a community weight management intervention over 5-, 10-, and 20-year time horizons. Transition probabilities, utilities, and resource use were informed by the IIH Weight Trial (IIH:WT), alongside the published literature. A probabilistic sensitivity analysis was conducted to characterize uncertainty within the model.

RESULTS

In the base case analysis, over a 20-year time horizon, bariatric surgery was "dominant," led to cost savings of £49,500, and generated an additional 1.16 quality-adjusted life years in comparison to the community weight management intervention. The probabilistic sensitivity analysis indicated a probability of 98% that bariatric surgery is the dominant option in terms of cost-effectiveness.

CONCLUSION

This economic modeling study has shown that when compared to community weight management, bariatric surgery is a highly cost-effective treatment option for IIH in women living with obesity. The model shows that surgery leads to long-term cost savings and health benefits, but that these do not occur until after 5 years post surgery, and then gradually increase over time.

Headache attributed to idiopathic intracranial hypertension and persistent post-idiopathic intracranial hypertension headache: A narrative review

OBJECTIVE

Headache is a near-universal sequela of idiopathic intracranial hypertension (IIH). The aim of this paper is to report current knowledge of headache in IIH and to identify therapeutic options.

BACKGROUND

Disability in IIH is predominantly driven by headache; thus, headache management is an urgent and unmet clinical need. At present, there is currently no scientific evidence for the directed use of abortive or preventative headache therapy.

METHODS

A detailed search of the scientific literature and narrative review was performed.

RESULTS

Headache in IIH is driven by raised intracranial pressure (ICP) and reduction of ICP has been reported in some studies to reduce headache. Despite resolution of papilledema and normalization of raised ICP, a majority suffer persistent post-IIH headache. The lack of evidence-based management approaches leaves many untreated. Where clinicians attempt to manage IIH headache, they use off-label therapies to target the prevailing headache phenotype. A recent prospective open-label study demonstrated the effective use of a calcitonin gene-related peptide monoclonal antibody therapy in IIH for persistent post-IIH headache.

CONCLUSIONS

There is overwhelming evidence of the headache burden in IIH. Studies are required to investigate the biological foundations of headache related to ICP and to develop treatments specifically directed to manage headache in IIH.

The Health Economic Evaluation of Bariatric Surgery Versus a Community Weight Management Intervention Analysis from the Idiopathic Intracranial Hypertension Weight Trial (IIH:WT)

BACKGROUND

The Idiopathic Intracranial Hypertension Weight Trial (IIH:WT) established the efficacy of bariatric surgery as compared to a community weight management intervention in reducing intracranial pressure in active IIH. The aim of this cost-effectiveness analysis was to evaluate the economic impact of these weight loss treatments for IIH.

METHODS

IIH:WT was a five-year randomised, controlled, parallel group, multicentre trial in the United Kingdom, where participants with active IIH and a body mass index ≥35 kg/m2 were randomly assigned (1:1) to receive access to bariatric surgery or a community weight management intervention. All clinical and quality of life data was recorded at baseline, 12 and 24 months. Economic evaluation was performed to assess health-care costs and cost-effectiveness. Evaluations were established on an intention to treat principle, followed by a sensitivity analysis using a per protocol analysis.

RESULTS

The mean total health care costs were GBP 1353 for the community weight management arm and GBP 5400 for the bariatric surgery arm over 24 months. The majority of costs for the bariatric surgery arm relate to the surgical procedure itself. The 85% who underwent bariatric surgery achieved a 12.5% reduction in intracranial pressure at 24 months as compared to 39% in the community weight management arm; a mean difference of 45% in favour of bariatric surgery. The cost effectiveness of bariatric surgery improved over time.

CONCLUSIONS

The IIH:WT was the first to compare the efficacy and cost-effectiveness of bariatric surgery with community weight management interventions in the setting of a randomised control trial. The cost-effectiveness of bariatric surgery improved over time and therefore the incremental cost of surgery when offset against the incremental reduction of intracranial pressure improved after 24 months, as compared with 12 months follow up.