Metabolic Dysfunction in New-Onset Idiopathic Intracranial Hypertension: Identification of Novel Biomarkers.

OBJECTIVE: Idiopathic intracranial hypertension (IIH) is a neurometabolic disease with an increasing incidence. The pathophysiology is unknown, but improvement of diagnosis and management requires discovery of novel biomarkers. Our objective was to identify such candidate biomarkers in IIH, and secondarily, test for associations between identified metabolites and disease severity. METHODS: This is a prospective case-control study with collection of cerebrospinal fluid (CSF), serum, and clinical data from new-onset, treatment-naïve patients with IIH (n = 60). Patients were included consecutively from 2 tertiary headache centers in Denmark, and age, sex, and body mass index (BMI) -matched healthy controls (n = 35) were recruited. Clinical data were retrieved at ocular remission (n = 55). Samples were analyzed using non-targeted mass spectrometry. RESULTS: Serum sphingosine 1-phosphate (S1P), adenosine, and glutamate were 0.46-fold (q < 0.0001), 0.25-fold (q = 0.0048), and 0.44-fold (q < 0.0001) lower, respectively, in IIH. CSF stearoyl-lysophosphatidylcholine (LysoPC-18) and 2-palmitoyl-lysophosphatidylcholine (LysoPC-16) were 0.42 (q = 0.0025) and 0.37 (q < 0.001) -fold lower. LysoPC-18 was higher in patients with moderate-severe versus mild papilledema (p = 0.022). LysoPC-18 correlated positively with retinal nerve fiber layer thickness (p = 0.0012, r = 0.42) and inversely with mean deviation on automated perimetry (p = 0.01, r = -0.35). Higher baseline serum S1P (p = 0.018) and lower CSF LysoPC-16 (p = 0.003) were associated with optic nerve atrophy at ocular remission. Pathway analysis suggests dysregulated lipid metabolism and redox disturbances in new-onset IIH. INTERPRETATION: We identify perturbed metabolism in new-onset IIH. S1P and LysoPC-16 demonstrate potential prognostic value due to association with subsequent optic nerve atrophy. This association between specific, differential metabolites and outcome provides substantial evidence for novel biomarkers of clinical significance that should be the focus of further targeted studies. ANN NEUROL 2024;96:595-607.

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.

Differentiation Between the Low and High Trans-Stenotic Pressure Gradient in Patients With Idiopathic Intracranial Hypertension Using 4D Flow MRI-Derived Hemodynamic Parameters.

BACKGROUND: Trans-stenotic pressure gradient (TPG) measurement is essential for idiopathic intracranial hypertension (IIH) patients with transverse sinus (TS) stenosis. Four-D flow MRI may provide a noninvasive imaging method for differentiation of IIH patients with different TPG. PURPOSE: To investigate the associations between 4D flow parameters and TPG, and to evaluate the diagnostic performance of 4D flow parameters in differentiating patients with high TPG (GroupHP) from low TPG (GroupLP). STUDY TYPE: Prospective. POPULATION: 31 IIH patients with TS stenosis (age, 38 ± 12 years; 23 females) and 5 healthy volunteers (age, 25 ± 1 years; 2 females). FIELD STRENGTH/SEQUENCE: 3T, 3D phase contrast MR venography, and gradient recalled echo 4D flow sequences. ASSESSMENT: Scan-rescan reproducibility of 4D flow parameters were performed. The correlation between TPG and flow parameters was analyzed. The netflow and velocity difference between inflow plane, outflow plane, and the stenosis plane were calculated and compared between GroupHP and GroupLP. STATISTICAL TESTS: Pearson's correlation or Spearman's rank correlation coefficient, Independent samples t-test or Wilcoxon rank-sum test, Intra-class correlation coefficient (ICC), Bland-Altman analyses, Receiver operating characteristic curves. A P value <0.05 was considered significant. RESULTS: Significant correlations were found between TPG and netflow parameters including Favg,out-s, Favg,in-s, Fmax,out-s, and Fmax,in-s (r = 0.525-0.565). Significant differences were found in Favg,out-s, Fmax,out-s, Favg,in-s, and Fmax,in-s between GroupHP and GroupLP. Using the cut-off value of 2.19 mL/sec, the Favg,out-s showed good estimate performance in distinguishing GroupHP from GroupLP (AUC = 0.856). The ICC (ranged 0.905-0.948) and Bland-Altman plots indicated good scan-rescan reproducibility. DATA CONCLUSIONS: 4D flow MRI derived flow parameters showed good correlations with TPG in IIH patients with TS stenosis. Netflow difference between outflow and stenosis location at TS shows the good performance in differentiating GroupHP and GroupLP cases. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

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.

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.

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 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.

Idiopathic intracranial hypertension secondary to fluoroquinolone therapy: French pharmacovigilance data review.

We investigate spontaneous reports of IIH related to fluoroquinolones recorded in the French national pharmacovigilance database in order to detect a possible pharmacovigilance signal. The association between IIH risk and fluoroquinolone exposure was assessed using a case/non-case study. Between 1985 and July 2023, 17 reports of IIH after fluoroquinolone exposure were recorded. No specific fluoroquinolone was predominant. IIH led to death in one case and blindness in one case. The Reporting Odds Ratio was 2.58 (95% confidence interval 1.59-4.19). We highlight statistically significant disproportionality, which constitutes a pharmacovigilance signal. IIH risk after fluoroquinolone exposure is a class effect.

Arachnoid granulations in idiopathic intracranial hypertension: Do they have an influence?

OBJECTIVE: The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with idiopathic intracranial hypertension (IIH) compared to healthy controls. BACKGROUND: IIH is characterized by increased intracranial pressure, which is associated with symptoms such as headache and visual disturbances. The role of cerebral venous drainage obstruction in IIH is the subject of ongoing research. MATERIALS AND METHODS: In this retrospective case-control study, 3D contrast-enhanced magnetic resonance images of a cohort of 43 patients with IIH were evaluated for (1) the number of AGs per venous sinus and (2) the diameters of the dural venous sinuses at the site of an AG and at standardized measurement points. In addition, the minimum width of the transverse/sigmoid sinus was measured. All data were compared to the same data from a cohort of 43 control participants. RESULTS: Patients with IIH showed less relative sinus narrowing by AG compared to controls (median: 7%, interquartile range [IQR] 10% vs. 11%, IQR 9% in controls; p = 0.009). In patients with IIH, sinus diameter was larger at the site of an AG (70 ± 25 mm2) compared to its diameter at the standardized measurement point (48 ± 23 mm2; p = 0.010). In the superior sagittal sinus (SSS), patients with IIH had smaller AGs (median: 3 mm2, IQR 2 mm2 vs. 5 mm2, IQR 3 mm2 in controls; p = 0.023) while the respective sinus segment was larger (median: 69 mm2; IQR 21 mm2 vs. 52 mm2, IQR 26 mm2 in controls; p = 0.002). The right transverse sinus was narrower in patients with IIH (41 ± 21 mm vs. 57 ± 20 mm in controls; p < 0.001). CONCLUSIONS: In contrast to our hypothesis, patients with IIH showed less pronounced relative sinus narrowing by AG compared to controls, especially within the SSS, where AGs were smaller and the corresponding sinus segment wider. Smaller AGs could result in lower cerebrospinal fluid resorption, favoring the development of IIH. Conversely, the smaller AGs could also be a consequence of IIH due to backpressure in the SSS because of the narrower transverse/sigmoid sinus, which widens the SSS and compresses the AG.

Impact of Ramadan fasting on vision and headache-related quality of life in women with idiopathic intracranial hypertension: A prospective observational study.

BACKGROUND: Ramadan fasting is an obligatory religious practice for Muslims. However, research data on the effect of Ramadan on idiopathic intracranial hypertension (IIH) symptoms are lacking. This study aimed to study the effect of Ramadan fasting on the severity of headache and visual symptoms and related quality-of-life activities. METHODS: This prospective cohort study targeted females diagnosed with IIH (n = 102) who were eligible to fast for Ramadan in 2023. The patients were recruited from the Neurology Clinic in Beni-Suef University Hospital, Egypt. Body mass index (BMI), monthly headache days and intensity of headache attacks, six-item Headache Impact Test (HIT-6), and the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) scores during Ramadan were compared to those during the (non-fasting) month of Shaaban, the preceding month to Ramadan. RESULTS: There was a significant increase in the BMI of patients with IIH in Ramadan compared to the (non-fasting) month of Shaaban, at a median (interquartile range [IQR]) of 30.5 (26.6-35.8) kg/m2 and 30.1 (26.6-35.2) kg/m2, respectively (p = 0.002). The median (IQR) value of monthly headache days was significantly increased during Ramadan in comparison to the (non-fasting) month of Shaaban, at 20 (11.5-30) vs. 15 (10-25) (p < 0.001). There was a statistically significant worsening in the visual analog scale (VAS) scores (median [IQR] 7 [5-8] vs. 6.5 [5-8]), HIT-6 scores (median [IQR] 61 [58-67] vs. 59 [53-61.5]), and NEI-VFQ-25 total scores (median [IQR] 1312.5 [1238.8-1435] vs 1290 [1165-1417.5]) during Ramadan in comparison to the (non-fasting) month of Shaaban (p < 0.001 for all comparisons). The change in BMI in Ramadan was positively correlated with the change in monthly headache days (r = 0.24, p = 0.014), VAS (r = 0.20, p = 0.043), HIT-6 (r = 0.25, p = 0.010) and NEI-VFQ-25 scores (r = 0.24, p = 0.016). CONCLUSION: Ramadan fasting had an aggravating effect on headache, visual symptoms, and related quality-of-life activities, which might be attributed to weight gain during this month. Whether proper nutritional management to prevent weight gain during Ramadan may help mitigate this worsening effect is a mission of future studies.

Novel Approaches to the Treatment of Idiopathic Intracranial Hypertension.

PURPOSE OF REVIEW: Idiopathic intracranial hypertension (IIH) typically affects women of childbearing age, is associated with recent weight gain, and can result in debilitating headache as well as papilledema that can cause vision loss. There have been advances in the medical and surgical treatment of affected patients with IIH that can improve outcomes and tolerability of therapy. RECENT FINDINGS: Medical treatment with agents that lower intracranial pressure through pathways other than carbonic anhydrase inhibition are being developed, and medically-directed weight loss as well as bariatric surgery now may be considered as primary therapy. New surgical options including venous sinus stenting have shown efficacy even with cases of severe vision loss. Our treatment options for IIH patients are becoming more diverse, and individualized treatment decisions are now possible to address specific components of the patient's disease manifestations and to lead to IIH remission.

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.

Occipital emissary vein existence and its impact on the diagnosis of idiopathic intracranial hypertension in pediatric patients.

PURPOSE: This study aimed to investigate the efficacy of occipital emissary vein (OEV) detection in the diagnosis of idiopathic intracranial hypertension (IHH) in the pediatric age group, and to compare the prevalence and luminal diameter of OEV in patients with IHH and in healthy control subjects. METHODS: Conventional magnetic resonance imaging findings were assessed in the patients with IHH and in healthy control subjects who were under the age of 18, by two observers. The presence and luminal dimension of OEV and transverse sinus stenosis were also evaluated and compared between these two groups with magnetic resonance venography techniques. RESULTS: The rate of OEV existence was 7 times higher in the IIH group compared to the control group based on the second observer outcome (p = 0.010, OR = 7.0), with a very good interobserver agreement (Ƙ = 0.85). The dimension of OEV ranged between 0.6 and 2.5 mm. There was no correlation found between the opening pressure and the dimension of OEV (p = 0.834). CONCLUSION: In conclusion, OEV existence could be an additional radiological finding for diagnosing IHH among pediatric patients, alongside other conventional findings.

Endovascular stenting for cerebral venous sinus stenosis secondary to meningioma invasion.

INTRODUCTION: Symptomatic intracranial hypertension (IH) due to venous outflow obstruction secondary to dural venous sinus (DVS) tumoral invasion affects up to 3% of intracranial meningioma patients. The literature regarding endovascular therapies of such patients is limited to a few case reports and a recent single-centre case series. PURPOSE: We describe our single-centre experience of endovascular therapy in patients with clinically symptomatic IH secondary to DVS meningioma invasion. METHODS: We performed a retrospective review of clinical and radiological data of all patients with refractory IH and meningiomas invading the DVS who were referred for possible DVS venoplasty and stenting. Seven endovascular procedures in six female patients were done. Presumed secondarily induced lateral transverse sinus stenosis was also stented in four patients as part of the primary intervention. RESULTS: All patients experienced complete symptomatic resolution at 6-month follow-up. Five patients had no symptom recurrence over a mean follow-up period of 3.5 years. One patient with multiple meningiomas developed recurrent IH 2 years following stenting secondary to in-stent tumour re-invasion. This was re-stented with consequent 6 months post-retreatment symptomatic relief at the time of writing. No procedure-related complications occurred. CONCLUSION: In the setting of DVS stenosis secondary to meningioma invasion, endovascular therapy is a safe and successful therapeutic option with promising mid-term results. The procedure should be considered in cases where complete surgical tumour resection is unlikely or carries a significant risk. If present, secondarily induced stenoses at the lateral ends of the transverse sinuses should also be considered for treatment.

Pituitary Dysfunction in Idiopathic Intracranial Hypertension: An Analysis of 80 Patients.

BACKGROUND: Empty sella is a commonly described imaging entity in patients with idiopathic intracranial hypertension (IIH). Though menstrual and hormonal disturbances have been associated with IIH, available literature lacks systematic analysis of pituitary hormonal disturbances in IIH. More so, the contribution of empty sella in causing pituitary hormonal abnormalities in patients of IIH has not been described. We carried out this study to systematically assess the pituitary hormonal abnormalities in patients with IIH and its relation to empty sella. METHODS: Eighty treatment naïve patients of IIH were recruited as per a predefined criterion. Magnetic resonance imaging (MRI) brain with detailed sella imaging and pituitary hormonal profile were done in all patients. RESULTS: Partial empty sella was seen in 55 patients (68.8%). Hormonal abnormalities were detected in 30 patients (37.5%), reduced cortisol levels in 20%, raised prolactin levels in 13.8%, low thyroid-stimulating hormone (TSH) levels in 3.8%, hypogonadism in 1.25%, and elevated levels of gonadotropins were found in 6.25% of participants. Hormonal disturbances were independent and were not associated with the presence of empty sella (p = 0.493). CONCLUSION: Hormonal abnormalities were observed in 37.5% patients with IIH. These abnormalities did not correlate with the presence or absence of empty sella. Pituitary dysfunction appears to be subclinical in IIH and responds to intracranial pressure reduction, not requiring specific hormonal therapies.

Myelin oligodendrocyte glycoprotein (MOG) associated optic neuritis in a patient with idiopathic intracranial hypertension (IIH) and compressive optic neuropathy case report.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disease (MOGAD) has a wide phenotypic expression and should be considered in a differential diagnosis of patients with optic disc edema and increased intracranial pressure because MOGAD can mimic IIH and compressive optic neuropathy. CASE PRESENTATION: A 53-year-old woman with a history of presumed idiopathic intracranial hypertension ("IIH") presented with new headache and visual loss. She had a BMI of 35.44 kg/m2 and a past medical history significant for depression, hepatitis C, hyperlipidemia, and uterine cancer post-hysterectomy. She had undergone multiple lumboperitoneal shunts for presumed IIH and had a prior pituitary adenoma resection. Her visual acuity was no light perception OD and counting fingers OS. After neuro-ophthalmic consultation, a repeat cranial MRI showed symmetric thin peripheral optic nerve sheath enhancement of the intra-orbital optic nerves OU. Serum MOG antibody was positive at 1:100 and she was treated with intravenous steroids followed by plasma exchange and rituximab. CONCLUSIONS: This case highlights the importance of considering MOGAD in the differential diagnosis of optic neuropathy. Although likely multifactorial, we believe that the lack of improvement in our case from presumed IIH and despite adequate neurosurgical decompression of a pituitary adenoma with compression of the optic apparatus reflected underlying unrecognized MOGAD. Clinicians should consider repeat imaging of the orbit (in addition to the head) in cases of atypical IIH or compressive optic neuropathy especially when the clinical course or response to therapy is poor or progressive.

Rebound Intracranial Hypertension.

PURPOSE OF REVIEW: Rebound intracranial hypertension (RIH) is a post-procedural treatment complication in patients with spontaneous intracranial hypotension (SIH) characterized by transient high-pressure headache symptoms. This article reviews the epidemiology, clinical features, risk factors, and treatment options for RIH. RECENT FINDINGS: This article discusses how changes in underlying venous pressure and craniospinal elastance can explain symptoms of RIH, idiopathic intracranial hypertension (IIH), and SIH. The pathophysiology of RIH provides a clue for how high and low intracranial pressure disorders, such as IIH and SIH, are connected on a shared spectrum.

Idiopathic Intracranial Hypertension After Abrupt Cessation of Medication: A Case Report of Abrupt Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist Cessation and Review of the Literature.

PURPOSE OF REVIEW: The purpose of this review is two-fold: (1) to discuss a case report of idiopathic intracranial hypertension (IIH) after abrupt cessation of a glucagon-like peptide-1 (GLP-1) receptor agonist with resultant rapid weight gain and (2) to review the literature regarding the potential role of GLP-1 receptor agonists in the treatment of IIH as well as potential pitfalls. RECENT FINDINGS: GLP-1 receptor agonists have become widely used to treat obesity. Obesity is a known risk factor for the development of IIH, though the precise pathophysiology is unclear. GLP-1 receptor agonists may help treat IIH by promoting weight loss, lipolysis of adipose tissue, and potentially decreasing the secretion of CSF, as was seen in rat models. Abrupt cessation of GLP-1 receptor agonists can result in regaining lost weight rapidly. In the case that we present, the patient stopped duraglutide abruptly due to lack of insurance coverage and regained the weight she had lost within a month. She subsequently developed IIH. GLP-1 receptor agonists have the potential to help treat IIH; however, this class of medication needs to be used carefully, as cessation of the medication and resultant rapid weight gain can result in IIH.

Undiagnosed sagittal synostosis as cause of "idiopathic" intracranial hypertension.

PURPOSE: Idiopathic intracranial hypertension (IIH) is a rare condition in children, but if diagnosed needs to be promptly treated to avoid clinical sequalae. The main purpose of this paper was to test our clinical experience with a cohort of normocephalic children with craniosynostosis who do not present in the routine way to craniofacial services, due to the normal head shape and age, diagnosed with IIH. METHODS: We retrospectively reviewed all children who were referred to neurosurgery from 2012 to 2022 for management of IIH on our prospectively kept database. We determined what treatments were offered and if there was an associated craniosynostosis. RESULTS: In total, 19 children were identified with an average age at referral of 11.5 years (st dev 4.0 years) with 11 male and 8 female. The most common presenting symptoms and signs were papilloedema (18/19), headaches (15/19), visual deterioration (9/19), nausea and vomiting (7/19) and diplopia (4/19). Five out of 19 children (26.3%) had a sagittal suture fused that was not identified at the time of treatment and all children were normocephalic. CONCLUSION: There is a cohort of children with IIH who will have concomitant craniosynostosis and ideally would benefit from cranial vault expansion as primary surgery rather than cerebrospinal fluid (CSF) diversion. We suggest all children with IIH requiring neurosurgical intervention have cross-sectional imaging to look for occult craniosynostosis prior to intervention.

The diagnostic value of MRI findings in pediatric idiopathic intracranial hypertension: a case-control study.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a rare medical condition in children. Based on the different radiological findings reported in various studies in pediatric IIH, this study was conducted to determine the diagnostic value of MRI findings in diagnosing IIH in children. METHODS: In this retrospective study, the medical records of all children aged 1 to 18 years who visited Ghaem Hospital in Mashhad, Iran, between 2012 and 2022 and were diagnosed with IIH were gathered. Forty-nine cases of children with IIH and 48 control cases of children with the first unprovoked seizure with no indications of increased intracranial pressure for comparison were selected. Patient demographic information and MRI findings were extracted. The comparison between different MRI findings in the case and control groups was conducted using statistical tests. RESULTS: In the case group, the mean diameter of the subarachnoid space expansion around the optic nerve was 5.96 ± 1.21, compared to 4.79 ± 0.33 in the control group, with statistically significant difference (P < 0.001). All the patients with flattening of the posterior globe or transverse sinus stenosis were in the case group, and the frequency of these findings in the case group was significantly higher than in the control group (P < 0.001). The majority of patients (95.5%) classified under category 3 and 4 of empty sella were part of the case group, and the statistical test results indicated a significant difference between the two groups (P < 0.001). The optic nerve sheath diameter cut-off of 5.35 mm, when used for expansion of the subarachnoid space around the optic nerve, with a sensitivity of 82% and a specificity of 100% in diagnosing IIH. CONCLUSION: The most reliable diagnostic indicators for diagnosing IIH in children are perioptic subarachnoid space expansion with high sensitivity, and posterior globe flattening and transverse sinus stenosis with high specificity.