Concordance between venous sinus pressure and intracranial pressure in patients investigated for idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a cause of chronic headaches that are probably driven by raised intracranial pressure (ICP). Cerebral venous sinus pressure is thought to play a role in the underlying pathology, but its relation with intracranial pressure requires further investigation. We aimed to evaluate the concordance between lumbar puncture opening pressure (LPOP) as indicator of the ICP and cerebral venous sinus pressure in patients investigated for IIH. METHODS: In this case-series replication study, all patients with IIH suspicion and who underwent cerebral venous sinus pressure measurement followed immediately by LP opening pressure (LPOP) measurement were retrospectively included. Pearson's correlation and measurement agreement (Bland-Altman plots) between venous pressure and LPOP were analyzed. RESULTS: 52 consecutive patients (46 women; median age, 31 years [IQR = 25-42]) were included. The mean pressure in the superior sagittal sinus (SSS) and in the torcular were 20.9mmHg (SD ± 7.3) and 20.8 mmHg (SD ± 6.8), respectively. The mean LPOP was 22mmHg (SD ± 6.4). Pressure measured in the transverse venous sinus, the torcular, and the SSS correlated with LPOP (p < 0.001). Bland-Altman plots showed that torcular pressure strongly agreed with LPOP (mean difference of 1.7mmHg). The limit of agreement (LOA) (mean difference ± 1.96SD) contained 98.1% of the differences between the two methods, confirming the concordance between the two measures. Torcular pressure and LPOP were consistent in patients with a trans-stenotic pressure gradient ≥ or < to 8 mmHg (mean difference: 1mmHg and 2.4mmHg, respectively), and for those with a LP OP ≥ or < to 18mmHg (mean difference: 1.8mmHg and 1.95mmHg, respectively). CONCLUSIONS: In patients investigated for IIH, the ICP measured at the LP is correlated and concordant with the torcular pressure. These results confirm previous findings and further corroborate the hypothesis that cerebral venous system plays a major role in CSF dynamics and ICP.

Idiopathic intracranial hypertension in Asians: a retrospective dual-center study.

BACKGROUND: There have been limited data on idiopathic intracranial hypertension (IIH) in Asians and there remain uncertainties whether a cerebrospinal fluid (CSF) pressure of 250 mm CSF is an optimum diagnostic cutoff. The aims of the present study included (1) characterization of IIH patients in Taiwan, (2) comparisons among different diagnostic criteria for IIH, and (3) comparisons between patients with CSF pressures of > 250 and 200-250 mm CSF. METHODS: This retrospective study involved IIH patients based on the modified Dandy criteria from two tertiary medical centers in Taiwan. Clinical manifestations were retrieved from electronic medical records, and findings on ophthalmologic examination and magnetic resonance images (MRIs) were reviewed. RESULTS: A total of 102 patients (71 F/31 M, mean age 33.4 ± 12.2 years, mean CSF pressure 282.5 ± 74.5 mm CSF) were identified, including 46 (45.1%) with obesity (body-mass index ≥ 27.5), and 57 (62.6%) with papilledema. Overall, 80 (78.4%), 55 (53.9%), 51 (50.0%), and 58 (56.9%) patients met the Second and Third Edition of International Classification of Headache Disorders, Friedman, and Korsbæk criteria, respectively. Patients in the 200-250 mm CSF group (n = 40) were less likely to have papilledema (48.5% vs. 70.7%, p = 0.035), transient visual obscuration (12.5% vs. 33.9%, p = 0.005), and horizontal diplopia (10.0% vs. 30.6%, p = 0.006), and had fewer signs on MRIs (2.2 ± 1.3 vs. 2.8 ± 1.0, p = 0.021) when compared with those with CSF pressures > 250 mm CSF (n = 62). However, the percentages of patients with headache (95.0% vs. 87.1%, p = 0.109) at baseline, chronic migraine at six months (31.6% vs. 25.0%, p = 0.578), and visual field defect (86.7% vs. 90.3%, p = 0.709) were similar. CONCLUSIONS: It was found that obesity and papilledema were less common in Asian IIH patients when compared with Caucasian patients. Although patients with CSF pressures of 200-250 mm CSF had a less severe phenotype, the risks of having headache or visual loss were comparable to those in the > 250 mm CSF group. It is possible that a diagnostic cutoff of > 200 mm CSF could be more suitable for Asians, although further studies are still needed.

Progress and recognition of idiopathic intracranial hypertension: A narrative review.

BACKGROUND: Idiopathic intracranial hypertension (IIH) mainly affects obese young women, causing elevated intracranial pressure, headaches, and papilledema, risking vision loss and severe headaches. Despite weight loss as the primary treatment, the underlying mechanisms remain unclear. Recent research explores novel therapeutic targets. AIMS: This review aimed to provide a comprehensive understanding of IIH's pathophysiology and clinical features to inform pathogenesis and improve treatment strategies. METHODS: Recent publications on IIH were searched and summarized using PubMed, Web of Science, and MEDLINE. RESULTS: The review highlights potential pathomechanisms and therapeutic advances in IIH. CONCLUSION: IIH incidence is rising, with growing evidence linking it to metabolic and hormonal disturbances. Early diagnosis and treatment remain challenging.

Unilateral Papilledema with Bilateral Optic Nerve Sheath Distension: A Case Report.

Bilateral edematous optic disc swelling from papilledema is caused by elevated intracranial pressure (ICP). Idiopathic intracranial hypertension (IIH), a clinical syndrome with elevated ICP of unclear etiology, is a frequent cause of this condition. IIH typically affects obese middle-aged females. Papilledema usually has a fairly symmetrical bilateral pattern. Unilateral papilledema is a rare disorder that must be detected early to avoid optic nerve damage. However, the etiology of unilateral papilledema remains unclear. Based on bilateral optic nerve sheath diameter measurements, we aimed to find an explanation for the unilaterality in this rare case.

[Idiopathic intracranial hypertension. Review of our experience in the last eight years (2016-2023)]. / Hipertensión intracraneal idiopática. Revisión de nuestra experiencia en los últimos ocho años (2016-2023).

INTRODUCTION: Idiopathic intracranial hypertension (IIH) or benign intracranial hypertension is a rare disease in childhood. The clinical presentation in pediatric patients can be very variable, being more unespecific in younger patients. PATIENTS AND METHODS: A retrospective descriptive study was carried out on patients diagnosed of IIH in the last eight years (2016-2023) in the neuropediatrics unit of a tertiary hospital. In the present study, the clinical-epidemiological characteristics and the diagnostic-therapeutic procedure carried out in each case were analyzed. RESULTS: We studied 14 patients, 57% were women. The average age at diagnosis was 9 years, headache was the most common reason for consultation. In all patients, papilledema was found in the fundus and neuroimaging didn´t find alterations. Optical coherence tomography has been carried out in 78.5% of the sample, > 80% of patients showed thickening of the retinal nerve fiber layer. All patients had a high cerebrospinal fluid opening pressure (>25 cmH2O). 57% of patients required treatment with acetazolamide, a carbonic anhydrase inhibito. In all patients the resolution was complete, however almost 30% of them have presented recurrences during follow-up. CONCLUSIONS: In recent years there has been an increase in the incidence of this entity, making early diagnosis and treatment essential to avoid possible irreversible damage.

TITLE: Hipertensión intracraneal idiopática. Revisión de nuestra experiencia en los últimos ocho años (2016-2023).Introducción. La hipertensión intracraneal idiopática (HII), o hipertensión intracraneal benigna, es una enfermedad poco frecuente en la infancia. La presentación clínica en pacientes pediátricos puede ser muy variable, y es más inespecífica a menor edad. Pacientes y métodos. Se ha realizado un estudio descriptivo retrospectivo de los pacientes diagnosticados de HII en los últimos ocho años (2016-2023) en la consulta de neuropediatría de un hospital de tercer nivel. En el presente estudio se analizaron las características clinicoepidemiológicas y el procedimiento diagnosticoterapéutico llevado a cabo en cada caso. Resultados. Se estudió a 14 pacientes, de los cuales el 57% eran mujeres. La edad media en el momento del diagnóstico fue de 9 años, y la cefalea fue el motivo de consulta más habitual. En todos los pacientes se constató papiledema en el fondo de ojo y una prueba de neuroimagen sin alteraciones. Se llevó a cabo una tomografía de coherencia óptica en el 78,5% de la muestra, y >80% de los pacientes presentaba engrosamiento de la capa de fibras nerviosas retiniana. La totalidad de los pacientes presentaba una presión de apertura de líquido cefalorraquídeo elevada (> 25 cmH2O). El 57% de los pacientes precisó como tratamiento acetazolamida, un inhibidor de la anhidrasa carbónica. En todos los pacientes la resolución fue completa; sin embargo, casi el 30% de ellos presentó recurrencias durante el seguimiento. Conclusiones. En los últimos años se ha mostrado un aumento en la incidencia de esta entidad, y es fundamental un diagnóstico y un tratamiento precoces para evitar posibles secuelas irreversibles.

Clinical profile and treatment outcomes of idiopathic intracranial hypertension: a multicenter study from Korea.

BACKGROUND: Currently, there is a relative lack of detailed reports regarding clinical presentation and outcome of idiopathic intracranial hypertension in Asians. This study aims to describe the clinical features and treatment outcomes of Korean patients with idiopathic intracranial hypertension. METHODS: We prospectively recruited patients with idiopathic intracranial hypertension from one hospital and retrospectively analyzed the medical records of 11 hospitals in Korea. We collected data regarding preceding medical conditions or suspected medication exposure, headache phenotypes, other associated symptoms, detailed neuroimaging findings, treatments, and outcomes after 1-2 and 3-6 months of treatment. RESULTS: Fifty-nine (83.1% women) patients were included. The mean body mass index was 29.11 (standard deviation, 5.87) kg/m2; only 27 patients (45.8%) had a body mass index of ≥ 30 kg/m2. Fifty-one (86.4%) patients experienced headaches, patterns of which included chronic migraine (15/51 [29.4%]), episodic migraine (8/51 [15.7%]), probable migraine (4/51 [7.8%]), chronic tension-type headache (3/51 [5.9%]), episodic tension-type headache (2/51 [3.9%]), probable tension-type headache (2/51 [3.9%]), and unclassified (17/51 [33.3%]). Medication overuse headache was diagnosed in 4/51 (7.8%) patients. After 3-6 months of treatment, the intracranial pressure normalized in 8/32 (25.0%), improved in 17/32 (53.1%), no changed in 7/32 (21.9%), and worsened in none. Over the same period, headaches remitted or significantly improved by more than 50% in 24/39 patients (61.5%), improved less than 50% in 9/39 (23.1%), and persisted or worsened in 6/39 (15.4%) patients. CONCLUSION: Our findings suggest that the features of Asian patients with idiopathic intracranial hypertension may be atypical (i.e., less likely obese, less female predominance). A wide spectrum of headache phenotypes was observed. Medical treatment resulted in overall favorable short-term outcomes; however, the headaches did not improve in a small proportion of patients.

Managing idiopathic intracranial hypertension in the eye clinic.

Idiopathic intracranial hypertension (IIH) is a neuro-ophthalmological condition characterised by a raised intracranial pressure and papilloedema that causes disabling headaches. The main risk factors of female sex and living with obesity have been known for some time, however the knowledge of the underlying pathophysiology is evolving. Papilloedema can impact the visual function, and the majority of people are offered acetazolamide. Those with sight threatening disease need urgent management, though there is little high quality evidence to recommend any particular surgical intervention. Headache treatment is an unmet clinical need and simple medication overuse advice has the potential to reduce the chronification of migraine-like headaches. IIH is emerging as a systemic metabolic disease distinct from people living with obesity alone. While weight loss is the main stay of disease modifying therapy this is challenging to access and many healthcare professionals that manage the condition have no formal training or accessible pathways for weight management. The aim of this "how to do it" article is to present the latest advances in knowledge of IIH that we pragmatically included in routine clinical care for people living with the condition.

The additive value of complementing diagnostic idiopathic intracranial hypertension criteria by MRI - an external validation study.

BACKGROUND: Recently, diagnostic criteria including a standardized MRI criterion were presented to identify patients suffering from idiopathic intracranial hypertension (IIH) proposing that IIH might be defined by two out of three objective findings (papilledema, ≥ 25 cm cerebrospinal fluid opening pressure (CSF-OP) and ≥ 3/4 neuroimaging signs). METHODS: To provide independent external validation, we retrospectively applied the proposed diagnostic criteria to our cohort of patients with clinical suspicion of IIH from the Vienna IIH database. Neuroimaging was reevaluated for IIH signs according to standardized definitions by a blinded expert neuroradiologist. We determined isolated diagnostic accuracy of the neuroimaging criterion (≥ 3/4 signs) as well as overall accuracy of the new proposed criteria. RESULTS: We included patients with IIH (n = 102) and patients without IIH (no-IIH, n = 23). Baseline characteristics were balanced between IIH and no-IIH groups, but papilledema and CSF-OP were significantly higher in IIH. For the presence of ≥ 3/4 MRI signs, sensitivity was 39.2% and specificity was 91.3% with positive predictive value (PPV) of 95.2% and negative predictive value (NPV) 25.3%. Reclassifying our cohort according to the 2/3 IIH definition correctly identified 100% of patients without IIH, with definite IIH and suggested to have IIH without papilledema by Friedman criteria, respectively. CONCLUSION: The standardized neuroimaging criteria are easily applicable in clinical routine and provide moderate sensitivity and excellent specificity to identify patients with IIH. Defining IIH by 2/3 criteria significantly simplifies diagnosis without compromising accuracy.

Consensus recommendations for the assessment and management of idiopathic intracranial hypertension in children and young people.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a potentially disabling condition. There is a lack of evidence and national guidance on how to diagnose and treat paediatric IIH, leading to variation in clinical practice. We conducted a national Delphi consensus via the Children's Headache Network to propose a best-practice diagnostic and therapeutic pathway. METHODS: The Delphi process was selected as the most appropriate methodology for examining current opinion among experts in the UK. 104 questions were considered by 66 healthcare professionals, addressing important aspects of IIH care: assessment, diagnosis, treatment, follow-up and surveillance. General paediatricians, paediatric neurologists, ophthalmologists, opticians, neuroradiologists and neurosurgeons with a clinical interest or experience in IIH, were invited to take part. RESULTS: The Delphi process consisted of three rounds comprising 104 questions (round 1, 67; round 2, 24; round 3 (ophthalmological), 13) and was completed between March 2019 and August 2021. There were 54 and 65 responders in the first and second rounds, respectively. The Delphi was endorsed by the Royal College of Ophthalmologists, which engaged 59 ophthalmologists for round 3. CONCLUSIONS: This UK-based Delphi consensus process reached agreement for the management of paediatric IIH and has been endorsed by the Children's Headache Network and more broadly, the British Paediatric Neurology Association. It provides a basis for a pragmatic clinical approach. The recommendations will help to improve clinical care while minimising under and over diagnosis.

Is increased activator protein 1 in cerebrospinal fluid as a potential biomarker that distinguishes idiopathic intracranial hypertension from multiple sclerosis?

OBJECTIVES: To distinguish whether idiopathic intracranial hypertension (IIH) is a condition predisposing to multiple sclerosis (MS) or an isolated disease, the current gene transcription factor Activator Protein-1 (AP-1) was evaluated with its potential to differentiate both diseases. BACKGROUND: The aim of this study was to investigate the use of AP-1 as biomarkers for the discrimination of IIH and MS. METHODS: AP-1, TNF-α, and IL-6 protein values in the CSF of the cases were evaluated by the ELISA method. The numerical measures of the groups and the ability of AP-1 to distinguish the groups were analyzed with the ROC curve. RESULTS: There was no difference between the groups in CSF TNF-α, IL-6, CSF, and serum biochemistry analyses. However, it was determined that the AP-1 concentration (pg/ml) was significantly higher in the IIH group, the sensitivity of AP-1 in separating those with IIH was 75%, and the specificity in separating those with MS was 60% in those with an AP-1 concentration of 606.5 and above. CONCLUSION: According to our results, the fact that CSF TNF-α and IL-6 values did not differ in IIH compared to MS revealed that IIH could not methodologically control MS, and AP-1 was a supportive parameter in differentiating both diseases (Tab. 2, Fig. 1, Ref. 31).

Neurofilament light chain is elevated in patients with newly diagnosed idiopathic intracranial hypertension: A prospective study.

BACKGROUND: Idiopathic intracranial hypertension is a secondary headache disorder potentially causing visual loss. Neurofilament light chain is a candidate, prognostic biomarker, but further studies of neuronal biomarkers are needed. Our objective was to investigate neurofilament light chain in cerebrospinal fluid (cNfL) and plasma (pNfL), amyloid-beta 42 (Aß-42), total-tau and phosphorylated-tau in cerebrospinal fluid in new-onset idiopathic intracranial hypertension. METHODS: Prospective case-control study including new-onset idiopathic intracranial hypertension and age, sex and BMI matched controls. Biomarkers were compared between patients and controls and related to papilledema, visual fields and opening pressure. RESULTS: We included 37 patients and 35 controls. Patients had higher age-adjusted cNfL (1.4 vs. 0.6 pg/mL, p-adjusted < 0.001), pNfL (0.5 vs. 0.3 pg/mL, p-adjusted < 0.001) and total-tau/Aß-42 (0.12 vs. 0.11, p-adjusted = 0.039). Significant, positive linear correlations were found between cNfL, pNfL, total-tau/Aß-42 and opening pressure. Patients with severe papilledema had elevated cNfL compared to mild-moderate papilledema (median cNfL: 4.3 pg/mL (3.7) versus 1.0 pg/mL (1.4), p-adjusted = 0.009). cNFL was inversely associated with perimetric mean deviation (r = -0.47, p-adjusted < 0.001). CONCLUSIONS: cNfL, pNfL and total-tau/Aß-42 were elevated in new-onset idiopathic intracranial hypertension. cNfL was associated with severity of papilledema and visual field defects at diagnosis. This indicates early axonal damage. Neurofilament light chain is a candidate biomarker for disease severity.

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.

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus.

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

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.

Are the ICHD-3 criteria for headache attributed to idiopathic intracranial hypertension valid? Headache phenotyping and field-testing in newly diagnosed idiopathic intracranial hypertension.

BACKGROUND: Headache burden is substantial in idiopathic intracranial hypertension. The classification of idiopathic intracranial hypertension headache by the International Classification of Headache Disorders (ICHD) is an important tool for research and clinical purposes. METHODS: We phenotyped headaches and tested sensitivity and specificity of the ICHD-3 criteria for idiopathic intracranial hypertension headache in a prospective cohort of patients suspected of idiopathic intracranial hypertension at two tertiary headache centers. RESULTS: Sensitivity was 93% and specificity was 100% of ICHD-3 criteria for idiopathic intracranial hypertension-related headache validated in idiopathic intracranial hypertension (n = 140) and patients in whom idiopathic intracranial hypertension was suspected but disproven (n = 103). The phenotype of new/worsened headaches related to idiopathic intracranial hypertension suspicion was equally migraine-like (p = 0.76) and tension-type-like (p = 0.08). Lumbar puncture opening pressure was higher (p < 0.0001) and pulsatile tinnitus more frequent (p < 0.0001) in idiopathic intracranial hypertension patients, but neither improved the applicability of the headache criteria, nor did papilledema. CONCLUSION: Headache phenotype is not distinct in idiopathic intracranial hypertension. ICHD-3 criteria for idiopathic intracranial hypertension headache are sensitive and specific, but simplicity can be improved without compromising accuracy. We propose that a new or worsened headache temporally related to active idiopathic intracranial hypertension is a sufficient criterion for idiopathic intracranial hypertension headache regardless of headache phenotype or accompanying symptoms, and that elements of idiopathic intracranial hypertension diagnostics (papilledema and opening pressure) be segregated from headache criteria.Trial Registration: ClinicalTrials.gov Identifier: NCT04032379.

Idiopathic intracranial hypertension associated with SARS-CoV-2 infection in an adult male patient: a case report and review of the literature.

BACKGROUND: Headache is a frequent symptom in coronavirus disease 2019 (COVID-19) patients, and idiopathic intracranial hypertension (pseudotumor cerebri) has been reported among patients who underwent lumbar puncture for persistent headaches. CASE PRESENTATION: A 45-year-old black man presented with dyspnea, cough, fever and headache for 05 days followed by blurring of vision associated with worsening of the headache. Physical examination was significant for tachypnea and oxygen desaturation and there were no abnormal neurologic findings. He tested positive for SARS-CoV-2 with nasopharyngeal swab PCR. His CSF opening pressure appeared high with normal CSF analysis and brain magnetic resonance imaging (MRI) revealed prominent subarachnoid space around the optic nerves and bilateral papilledema. He had significant improvement with medical therapy alone. CONCLUSION: Idiopathic intracranial hypertension (IIH) may occur in association with SARS-CoV-2 infection and should be considered when making a differential diagnosis for headache and blurring of vision. COVID-19 may play a role in the development of intracranial hypertension, even in the absence of known risk factors. Early diagnosis and treatment of IIH has paramount importance to prevent vision loss and other morbidities.

The impact of eating disorders on idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) occurs more frequently in obese females of childbearing age. A link between eating disorders and poor outcome has been suggested but remains unproven. METHODS: This prospective field study at two tertiary headache centers included patients with clinically suspected IIH after standardized diagnostic work-up. Eating disorders were evaluated using validated questionnaires (EDQs). Primary outcome was the impact of eating disorders on IIH severity and outcome, secondary outcome was the prevalence and type of eating disorders in IIH compared to controls. RESULTS: We screened 326 patients; 143 patients replied to the EDQs and were classified as 'IIH' or 'non-IIH' patients. The demographic profile of EDQ-respondents and non-respondents was similar. Presence of an eating disorder did not impact IIH severity (lumbar puncture opening pressure (p = 0.63), perimetric mean deviation (p = 0.18), papilledema (Frisén grad 1-3; p = 0.53)) nor IIH outcome (optic nerve atrophy (p = 0.6), impaired visual fields (p = 0.18)). Moreover, we found no differences in the prevalence and type of eating disorders when comparing IIH with non-IIH patients (p = 0.09). CONCLUSION: Eating disorders did not affect IIH severity or outcome. We found the same prevalence and distribution pattern of eating disorders in IIH and non-IIH patients advocating against a direct link between IIH and eating disorders.

Assessment of the relationship between structural and functional tests in patients with idiopathic intracranial hypertension.

PURPOSE: To assess the relationship between structural and functional tests in mild and moderate idiopathic intracranial hypertension (IIH). METHODS: Patients with mild and moderate IIH and a control group were enrolled. Best-corrected visual acuity (BCVA), macular ganglion cell layer (MGCL) thickness, peripapillary retinal nerve fiber layer (pp RNFL) thickness, perimetric mean deviation (MD), and photopic negative responses (PhNR) of the electroretinogram were recorded. The associations between structural (pp RNFL and MGCL thickness) and functional (PhNR amplitude, MD and BCVA) parameters were assessed. RESULTS: 154 eyes from 78 subjects (74 eyes from IIH patients and 80 eyes from healthy subjects) were included in this comparative observational study. The MGCL thickness, VA, pp RNFL, and PhNR base-to-trough (BT) amplitude were significantly worse in moderate IIH. The BCVA and MD were associated with MGCL thickness only in moderate IIH. The relationship between MD and MGCL thickness started when MD fell below -5.7 dB. CONCLUSIONS: The association between functional and structural parameters varies between mild and moderate IIH. The MD and MGCL thickness outperformed in assessing disease severity in mild and moderate IIH, respectively. The association between MD and MGCL thickness could be considered in IIH severity categorization.