An update on idiopathic intracranial hypertension in adults: a look at pathophysiology, diagnostic approach and management

Sedentary behavior from television watching elevates GlycA levels: A bidirectional Mendelian randomization study

BACKGROUND

Current evidence linking sedentary behavior (SB), physical activity (PA), and inflammation raises questions about their causal relationships, prompting concerns about potential residual confounding or reverse causation.

METHODS

A bidirectional Mendelian randomization (MR) analysis was conducted. SB data (n = 408,815) from "computer use," "television watching," and "driving" were included. The PA data encompassed nine types of PA (n = 460,376) over the last four weeks and included data on the frequency of vigorous PA (n = 440,512) and moderate PA (n = 440,266) for over 10 min. Additionally, three genome-wide association study datasets (n = 64,949) on light, moderate, and vigorous exercise were included to minimize potential bias from changes in exercise intensity. Inflammation data included levels of C-reactive protein (CRP) (n = 575,531), glycoprotein acetyl (GlycA) (n = 115,082), interleukin (IL)-8, IL-6, IL-6 receptor (IL-6R), and soluble IL-6R (sIL-6R) (n = 35,278). All datasets represented participants of European ancestry.

RESULTS

Television watching as an SB showed significant positive causal effects on GlycA and CRP (inverse variance weighted (IVW), odds ratios (OR): 1.34, 95% confidence intervals (CI): 1.25-1.44, p = 3.570 × 10-17; IVW, OR: 1.21, 95% CI: 1.16-1.26, p = 1.500 × 10-19, respectively), with more robust evidence for GlycA. In the direction from inflammation to PA, a negative causal relationship between CRP and"number of days/week of moderate PA 10+ minutes"was observed (IVW, OR: 0.92, 95% CI: 0.89-0.96, p = 3.260 × 10-5). Sensitivity analyses were used to verify the robustness and reliability of the results. However, other initially observed associations ceased to be significant after controlling for obesity-related confounders.

CONCLUSION

Our MR analysis suggested a potential causal relationship between television watching and chronic low-grade inflammation, with more substantial evidence for GlycA. Additionally, different types of SB may have varying effects on inflammation. Obesity-related traits could partly or entirely influence the relationship between SB, PA, and inflammatory markers. Furthermore, Our findings indicate that SB is an independent risk factor for inflammation, separate from PA, and highlight the different mechanisms by which SB and PA affect disease.

An interdisciplinary integrated specialized one-stop outpatient clinic for idiopathic intracranial hypertension - a comprehensive assessment of patient satisfaction

BACKGROUND

Management of idiopathic intracranial hypertension (IIH) is complex requiring contributions from multiple specialized disciplines. In practice, this creates considerable organizational and communicational challenges. To meet those challenges, we established an interdisciplinary integrated outpatient clinic for IIH with a central coordination and a one-stop concept. Here, we aimed to evaluate effects of this one-stop concept on subjective patient satisfaction and economic outcome in patients with IIH.

METHODS

In a retrospective cohort study, we compared the one-stop era with integrated care (IC, 1-JUL-2021 to 31-DEC-2022) to a reference group receiving standard care (SC, 1-JUL-2018 to 31-DEC-2019) regarding subjective patient satisfaction (assessed by the Vienna Patient Inventory). Multivariable binary linear regression models were used to adjust for confounders.

RESULTS

Baseline characteristics of the IC group (n = 85) and SC group (n = 81) were comparable (female: 90.6% vs. 90.1%; mean age: 33.6 vs. 32.8 years, educational level: ≥9 years of education 60.0% vs. 59.3%; located in Vienna 75.3% vs. 76.5%). Compared to SC, management within IC concept was associated with statistically significantly higher subjective patient satisfaction (beta = 0.93; p < 0.001) with the strongest effects observed in satisfaction with treatment accessibility and availability (beta = 2.05; p < 0.001). Subgroup analyses of patients with migration background and language barrier consistently indicated stronger effects of IC in these groups.

CONCLUSIONS

Interdisciplinary integrated management of IIH statistically significantly and clinically meaningfully improves patient satisfaction - particularly in socioeconomically underprivileged patient groups. Providing structured central coordination to facilitate and improve access to interdisciplinary management provides means to further improve outcome.

Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Management of Idiopathic Intracranial Hypertension: A Case Report

ABSTRACT

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a neurological disorder characterized by elevated intracranial pressure, affecting predominantly obese women of childbearing age. Early recognition and comprehensive management are vital for preventing severe complications, particularly vision loss. METHODS: This study reports a case of a 27-year-old woman who presented with chronic headaches and blurred vision. Notable findings included headaches that were intensified upon waking and exacerbated by activities that elevated intracranial pressure. The patient also reported nausea, vomiting, transient visual obscurations, and pulsatile tinnitus. After a clinical examination, she was given a diagnosis of IIH. RESULTS: The patient underwent a lumbar-peritoneal shunt procedure to alleviate her symptoms in conjunction with medication treatment. This case study highlights the importance of a multidisciplinary approach in diagnosing and treating IIH. In particular, weight management emerged as a crucial preventive measure against IIH recurrence. CONCLUSION: A multidisciplinary team strategy can enhance outcomes and quality of life, accentuating the need for continued research into IIH recurrence, treatments, and wider implications.

Tortuous occipital emissary vein combined with dural venous sinus stenosis in contrast-enhanced MRV for evaluation of idiopathic intracranial hypertension

PURPOSE

Venous outflow impediment is increasingly recognized in idiopathic intracranial hypertension (IIH). We aim to search for the value of tortuous occipital emissary vein (OEV) in IIH by integrating measurable transverse sinus (TS) stenosis in contrast-enhanced MR venography (CE-MRV).

METHODS

Twenty-one IIH patients were evaluated with CE-MRV. Each patient had high LP opening pressure (> 25 cm.H2O), and presented papilledema. Age- and sex-matched 21 control subjects who underwent cranial CE-MRV were selected. The OEV and the following features: intraosseous diameter of more than 3 mm, twisted course, and continuous with prominent sub-occipital extracranial veins were named tortuous OEV. TS stenosis was measured by utilizing the coronal T1-VIBE series to calculate quantitative metrics such as TS max./min.. The tortuous OEV and TS max./min. were registered to create a bivariate logistic regression model to assess the performance of tortuous OEV for IIH when accompanied by TS stenosis.

RESULTS

Six (29%) tortuous OEVs were observed in the IIH group, while no tortuous OEV was identified in the control group (p = 0.021). The mean TSmax./min. was 2.48 ± 1.19 in patients with IIH and 1.23 ± 0.33 in the control group (p < 0.001). According to regression analysis, tortuous OEV is not predictive of IIH (p = 0.999), while the higher TSmax./min. (> 1.69) is predictive of IIH (p = 0.022, OR: 8.9; %95 CI; 1.4-59.0) when accompanied together.

CONCLUSION

Tortuous occipital emissary vein is more frequently seen in patients with IIH. However, the tortuous appearance alone does not predict idiopathic intracranial hypertension unless associated with measurable transverse sinus narrowing in CE-MRV.

An interdisciplinary integrated specialized one-stop outpatient clinic for idiopathic intracranial hypertension - an assessment of sick leave, presenteeism, and health care utilization

BACKGROUND

Management of idiopathic intracranial hypertension (IIH) is complex requiring contributions from multiple specialized disciplines. In practice, this creates considerable organizational and communicational challenges. To meet those challenges, we established an interdisciplinary integrated outpatient clinic for IIH with a central coordination and a one-stop- concept. Here, we aimed to evaluate effects of this concept on sick leave, presenteeism, and health care utilization.

METHODS

In a retrospective cohort study, we compared the one-stop era with integrated care (IC, 1-JUL-2021 to 31-DEC-2022) to a reference group receiving standard care (SC, 1-JUL-2018 to 31-DEC-2019) regarding economic outcome parameters assessed over 6 months. Multivariate binary logistic regression models were used to adjust for confounders.

RESULTS

Baseline characteristics of the IC group (n = 85) and SC group (n = 81) were comparable (female: 90.6% vs. 90.1%; mean age: 33.6 vs. 32.8 years, educational level: ≥9 years of education 60.0% vs. 59.3%; located in Vienna 75.3% vs. 76.5%). Compared to SC, the IC group showed significantly fewer days with sick leave or presenteeism (-5 days/month), fewer unscheduled contacts for IIH-specific problems (-2.3/month), and fewer physician or hospital contacts in general (-4.1 contacts/month). Subgroup analyses of patients with migration background and language barrier consistently indicated stronger effects of the IC concept in these groups.

CONCLUSIONS

Interdisciplinary integrated management significantly improves the burden of IIH in terms of sick leave, presenteeism and healthcare consultations - particularly in socioeconomically underprivileged patient groups.

Longitudinal optical coherence tomography indices in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) may result in optic nerve fiber loss and even atrophy. The timing of the optical coherence tomography (OCT) indices reaching the lowest point (nadir) and the factors that predict the patient's anatomical outcome are not known. We aimed to determine the timing and the factors that affect nadir retinal nerve fiber layer (RNFL) thickness. The medical records of 99 IIH patients who were treated from December 2009 to January 2020 were retrospectively reviewed. The mean RNFL thickness at presentation was 263.5 ± 106.4 µm. The mean time to nadir was 7.9 ± 6.3 months. The average RNFL and ganglion cell complex (GCC) thickness at the nadir were 92.6 ± 14.5 µm (47% showed thinning) and 77.9 ± 27.8 µm (70% showed thinning), respectively. The Frisén disc edema stage and average RNFL thickness at baseline correlated with a longer time to nadir, (r = 0.28 P = 0.003 and r = 0.24, P = 0.012, respectively). The nadir average RNFL thickness and the nadir average GCC thickness (r = 0.32, P = 0.001, r = 0.29, P = 0.002, respectively) correlated with the baseline visual field mean deviation. The final anatomical outcome of IIH episodes in this study resulted in RNFL and GCC thinning. The time to RNFL nadir and its values correlated with IIH severity at presentation.

Diagnosis and treatment of disorders of intracranial pressure: consensus statement of the Spanish Society of Neurology's Headache Study Group

Primary intracranial pressure disorders include idiopathic intracranial hypertension and spontaneous intracranial hypotension. Remarkable advances have been made in the diagnosis and treatment of these 2entities in recent years. Therefore, the Spanish Society of Neurology's Headache Study Group (GECSEN) deemed it necessary to prepare this consensus statement, including diagnostic and therapeutic algorithms to facilitate and improve the management of these disorders in clinical practice. This document was created by a committee of experts belonging to GECSEN, and is based on a systematic review of the literature, incorporating the experience of the participants, and establishes practical recommendations with levels of evidence and grades of recommendation.

MRI signs of intracranial hypertension in morbidly obese and normal-weight individuals

PURPOSE

 Idiopathic intracranial hypertension (IIH) is associated with intracranial abnormalities, although not obligatory, which can be detected with cranial MRI. Obesity is an important risk factor for IIH and a pathogenetic link is suspected but the extent to which these MRI signs are already related to obesity has not yet been examined. We investigated whether IIH-MRI signs are present more often in obese individuals with a BMI > 30 kg/m² than in individuals of normal weight.

MATERIALS AND METHODS

 Brain MRI of 32 obese and 53 normal-weight participants from the Food-Chain-Plus cohort were analyzed for three main signs of IIH: (I) stenosis of the transverse sinus, (II) increased width of the optic nerve sheath, and (III) reduction of pituitary height. In addition, a scoring system for the MRI signs was applied. Furthermore, tortuosity of the optic nerve and flattening of the posterior globe were considered as additional MRI signs.

RESULTS

 Obese participants had a significantly higher MRI score (p < 0.001) than those in the normal-weight cohort, with significant differences in quantitative measurements of cerebral venous sinus stenosis (p < 0.001), widening of the optic nerve sheath (p < 0.05), and flattening of the pituitary gland (p < 0.05) also always being observed more frequently and in a more pronounced manner in the obese group. Furthermore, our findings correlated significantly with BMI and proportionately with hip and waist circumference.

CONCLUSION

 Obese individuals show a significantly higher prevalence of cerebral MRI signs related to IIH. This supports the hypothesis that obesity is a risk factor for possible intracranial hypertension and reinforces the suspicion that obesity is involved in the pathomechanism of IIH.

KEY POINTS

  · Obesity is associated with changes such as those seen in IIH.. · BMI, weight, and body measurements correlate with the expression of MRI signs of IIH.. · To prevent IIH symptoms in obesity, the pathomechanism must be further clarified..

Optic Nerve Head and Retinal Changes in Idiopathic Intracranial Hypertension: Correlation with Short-Term Cerebrospinal Fluid Pressure Monitoring

BACKGROUND

We aimed to assess the status of the optic nerve and retina by optical coherence tomography (OCT) in a group of patients with idiopathic intracranial hypertension (IIH) on the basis of dynamic changes in intracranial pressure.

METHODS

This observational and cross-sectional study included patients affected by idiopathic intracranial hypertension with papilledema (IIHWP) and patients with idiopathic intracranial hypertension without papilledema (IIHWOP). All participants underwent an OCT examination of the macula and optic nerve head. Parameters related to intracranial pressure, including cerebrospinal fluid (CSF) opening pressure (oCSFp), CSF mean pressure (mCSFp), and pulse wave amplitude (PWA), were included in the analysis.

RESULTS

Out of the 22 subjects enlisted for the study, a total of 16 patients suggestive of IIH were finally enrolled. Papilledema was detected in nine subjects (56.2%) and seven patients were affected by IIHWOP (43.7%). The OCT examination showed a higher mean RNFL thickness in IIHWP patients in comparison to IIHWOP in both eyes (p < 0.05 and p < 0.01, respectively). Intracranial pressure (ICP) measurements showed that IIHWP had higher values of oCSFp, mCSFp, and PWA compared to IIHWOP (p = 0.0001, p = 0.0001, and p = 0.0001, respectively). In addition, ICP parameters significantly correlated with RNFL.

CONCLUSIONS

Clinical parameters suggestive of idiopathic intracranial hypertension are associated with retina and optic nerve OCT parameters. OCT is a useful tool to detect these alterations in a non-invasive fashion.

What Are the Predictors for and Psychosocial Correlates of Chronic Headache After Moderate to Severe Traumatic Brain Injury?

OBJECTIVE

Although headache (HA) is a common sequela of traumatic brain injury (TBI), early predictors of chronic HA after moderate to severe TBI are not well established, and the relationship chronic HA has with psychosocial functioning is understudied. Thus, we sought to (1) determine demographic and injury predictors of chronic HA 1 or more years after moderate to severe TBI and (2) examine associations between chronic HA and psychosocial outcomes.

SETTING

Community.

PARTICIPANTS

Participants in the TBI Model System (TBIMS) with moderate to severe TBI who consented for additional chronic pain questionnaires at the time of TBIMS follow-up.

DESIGN

Multisite, observational cohort study using LASSO (least absolute shrinkage and selection operator) regression for prediction modeling and independent t tests for psychosocial associations.

MAIN OUTCOME MEASURES

Chronic HA after TBI at year 1 or 2 postinjury and more remotely (5 or more years).

RESULTS

The LASSO model for chronic HA at 1 to 2 years achieved acceptable predictability (cross-validated area under the curve [AUC] = 0.70). At 5 or more years, predictability was nearly acceptable (cross-validated AUC = 0.68), but much more complex, with more than twice as many variables contributing. Injury characteristics had stronger predictive value at postinjury years 1 to 2 versus 5 or more years, especially sustained intracranial pressure elevation (odds ratio [OR] = 3.8) and skull fragments on head computed tomography (CT) (OR = 2.5). Additional TBI(s) was a risk factor at both time frames, as were multiple socioeconomic characteristics, including lower education level, younger age, female gender, and Black race. Lower education level was a particularly strong predictor at 5 or more years (OR up to 3.5). Emotional and participation outcomes were broadly poorer among persons with chronic HA after moderate to severe TBI.

CONCLUSIONS

Among people with moderate to severe TBI, chronic HA is associated with significant psychosocial burden. The identified risk factors will enable targeted clinical screening and monitoring strategies to enhance clinical care pathways that could lead to better outcomes. They may also be useful as stratification or covariates in future clinical trial research on treatments.

Optic Nerve Head Changes Measured by Swept Source Optical Coherence Tomography and Angiography in Patients with Intracranial Hypertension

INTRODUCTION

This study explored the structural and microvascular changes in the optic nerve head (ONH) of patients with intracranial hypertension (IH) by using swept-source optical coherence tomography (SS-OCT)/OCT angiography (OCTA) and evaluated their association with clinical features.

METHODS

The optic disc morphology, peripapillary retinal nerve fiber layer (pRNFL), ganglion cell-inner plexiform layer (GCIPL), and microvascular densities of the nerve fiber layer plexus (NFLP), superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were measured by the SS-OCT/OCTA tool. Frisen score, visual acuity, and intracranial pressure were assessed and recorded in patients with IH.

RESULTS

Sixty-one patients with IH and 65 controls were included in this study. Patients with IH showed thicker pRNFL and GCIPL thickness with larger ONH rim area when compared to controls (P < 0.001). Microvascular densities were increased in NFLP while densities were reduced in SVP, ICP, and DCP when compared to controls (P < 0.001). Structural thickness and microvascular densities were significantly correlated with Frisen scores (P < 0.05) and intracranial pressure (P < 0.05) in patients with IH.

CONCLUSION

Structural and microvasculature variations of the ONH were found in patients with IH compared to controls. Importantly, we showed that structural and microvascular changes in the ONH were correlated with their Frisen score and intracranial pressure in patients with IH.

Stenting versus medical treatment for idiopathic intracranial hypertension: a matched-control study

BACKGROUND

This prospective cohort study compared the outcomes of stenting and medical treatment for patients with idiopathic intracranial hypertension (IIH) and venous sinus stenosis (VSS).

METHODS

In this single-center cohort study, patients with IIH and VSS were evaluated between January 2014 and December 2019 with follow-up periods of 1, 3, and 6 months. The patients received either stenting or medical treatment. The two groups underwent 1:1 matching using propensity score analysis, and the clinical outcomes were compared.

RESULTS

Following 1:1 matching, 36 patients who underwent stenting and 36 who underwent medical treatment were matched. The median improvements in the papilledema Frisén grade were greater in the stenting group at 1 month (-2 vs 0), 3 months (-3 vs -1), and 6 months (-3 vs -1) than in the medical treatment group. Patients who received stenting treatment had a significantly higher prevalence of complete resolution of their respective symptoms (headache, tinnitus, or visual disturbances) at 3 months (58.3% vs 13.9%, OR 8.68, 95% CI 2.74 to 27.52) and 6 months (80.6% vs 22.2%, OR 14.50, 95% CI 4.64 to 45.32) than those receiving medical treatment.

CONCLUSIONS

This matched-control study shows that stenting has a greater efficacy rate and rapid resolution of papilledema and its respective symptoms compared with medical treatment.

Debilitating trigeminal neuralgia secondary to idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is characterized by raised intracranial pressure with unknown etiology. The most common neurological manifestations are headache and visual loss. Often, other cranial nerve impairments are also found, most commonly in the VI nerve. Trigeminal neuralgia (TN) is a debilitating condition that is most frequently caused by neurovascular pathology, but TN secondary to IIH is a rare and poorly described topic. Possible explanations of TN in these patients include the distortion of the local anatomy at CN entry zones and fluid displacement causing distortion of the Meckel's cave. In the case below we describe the clinical course of an obese female patient with TN-like pain who underwent a ventriculoperitoneal shunt to treat IIH and experienced complete resolution of both conditions.

Long-term safety and efficacy of stenting on correcting internal jugular vein and cerebral venous sinus stenosis

OBJECTIVES

To compare the long-term safety and efficacy of stenting in correcting cerebral venous sinus stenosis (CVSS) and internal jugular venous stenosis (IJVS).

METHODS

Patients confirmed with CVSS or IJVS by imaging were enrolled in this real-world study from 2014 through 2021. Clinical characteristics and long-term outcomes of these two diseases entities post-stenting were followed up and compared.

RESULTS

Three hundred and nineteen patients were enrolled in this study, with a mean age of 48.83 years and a BMI of 25.08 on average. In which, 144 patients underwent stenting, the stenotic segments were corrected and the venous blood flow was restored immediately post-stenting. At 6.15 ± 1.67 days follow-up, significant improvement was observed in headache, tinnitus, insomnia, ICP, and mean pressure gradient in both groups (all p < 0.05). At 30.53 ± 4.41 months follow-up post-stenting, the headache, tinnitus, visual loss, papilledema, and insomnia were attenuated remarkably or even completely disappeared. The Frisen papilledema grade scores declined from 2 (0-4) to 1 (0-3) in IJVS group and from 4 (1-5) to 1 (0-4) in CVSS group compared to the baseline. One hundred and twenty-seven out of the 144 patients (95.5%) maintained sufficient blood flow verified by followed up computed tomographic venography or contrast-enhanced magnetic resonance angiography. Adverse events related to stenting included three cases of intraluminal restenosis and three cases of in-stent thrombosis, no intracranial hemorrhage, venous thromboembolisms, stent-adjacent stenosis, and stent displacement occurred.

INTERPRETATION

Using stents to correct IH and related neurological issues has shown to be a safe and effective approach for both IJVS and CVSS.

Current and emerging diagnostic and management approaches for idiopathic intracranial hypertension

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Higher cerebrospinal fluid (CSF) opening pressure in patients with idiopatic intracranial hypertension (IIH) with permanent visual impairment

Objective The aim of this study was to identify potential visual prognostic markers in patients with idiopathic intracranial hypertension (IIH).  Methods Patients with IIH of an outpatient headache clinic in São Paulo, Brazil, were retrospectively evaluated and divided in two groups with and without the presence of permanent visual deficit attributed to IIH. Body mass index (BMI), opening CSF pressure, and the frequency of IIH related MRI abnormalities were compared between these two groups.  Results Twenty-nine patients, with 35,39±9,93 years, being twenty-eight female (96.55%) were included in the study. Reduced visual acuity attributed to IIH was registered in 16 (55.17%). According to BMI 17.4% had overweight and 82.6% were obese. Brain MRI was normal in 6 (20.69%). BMI, obesity, and the presence of MRI abnormalities were not associated with visual impairment. Initial CSF opening pressure was significantly higher in the group of patients with reduced visual acuity (40.4±13.14 x 30.5±3.41, P=0,015).  Conclusion Higher CSF opening pressure at onset was significantly associated with a higher percentage of visual impairment in patients with IIH suggesting this measure as a potential prognostic marker for patients with IIH.  

Cerebrospinal fluid (CSF) and idiopatic intracranial hypertension (IIH): a critical review

Pseudotumor cerebri is a syndrome that results from increased intracranial pressure. The main symptoms are headache, vision disturbances, and pulsatile tinnitus. Definitive diagnosis requires the presence of clinical and/or radiological signs of intracranial hypertension, high opening pressure on lumbar puncture (LP), and normal CSF constitution. Several studies have evaluated new contributions of CSF in the clinical evaluation and the in understanding of the pathophysiology of pseudotumor cerebri. Such studies have included the analysis of inflammatory biomarkers, adipokines, proteomic analysis, and CSF flow studies. In this review, we present the main results obtained so far and critically discuss the present status and the potential role of research involving the CSF in this condition. Based on current knowledge, it is possible to conclude that CSF research with new biomarkers has not yet provided information that can be employed in clinical practice at this moment. However, a better understanding of the constitution and dynamics of CSF circulation in patients with pseudotumor cerebri has brought some information about this condition and can potentially improve our knowledge about this condition in the future.

Intracranial pressure and veins

Summary: This review summarizes the relationship between intracranial pressure and the venous system as far as ultrasound methods are concerned. Although the pressure in cortical veins is tightly and linearly coupled to the intracranial pressure, venous flow velocities in the basal veins are not. However, venous flow velocities reflect better the local cerebral blood flow than measurements in arteries. Therefore, they correlate better with clinical outcome in head trauma and subarachnoid hemorrhage. Transorbital sonography with measurement of the optic nerve sheath diameter and optic disk elevation has evolved to a valuable point of care diagnostic tool in idiopathic intracranial hypertension. In cerebral vein and sinus thrombosis ultrasound is at best a supplementary diagnostic tool, which may have a value in patient follow-up.

Why don't ventricles dilate in pseudotumor cerebri? A circuit model of the cerebral windkessel

OBJECTIVE

Pseudotumor cerebri is a disorder of intracranial dynamics characterized by elevated intracranial pressure (ICP) and chronic cerebral venous hypertension without structural abnormalities. A perplexing feature of pseudotumor is the absence of the ventriculomegaly found in obstructive hydrocephalus, although both diseases are associated with increased resistance to cerebrospinal fluid (CSF) resorption. Traditionally, the pathophysiology of ventricular dilation and obstructive hydrocephalus has been attributed to the backup of CSF due to impaired absorption, and it is unclear why backup of CSF with resulting ventriculomegaly would not occur in pseudotumor. In this study, the authors used an electrical circuit model to simulate the cerebral windkessel effect and explain the presence of ventriculomegaly in obstructive hydrocephalus but not in pseudotumor cerebri.

METHODS

The cerebral windkessel is a band-stop filter that dampens the arterial blood pressure pulse in the cranium. The authors used a tank circuit with parallel inductance and capacitance to model the windkessel. The authors distinguished the smooth flow of blood and CSF and the pulsatile flow of blood and CSF by using direct current (DC) and alternating current (AC) sources, respectively. The authors measured the dampening notch from ABP to ICP as the band-stop filter of the windkessel.

RESULTS

In obstructive hydrocephalus, loss of CSF pathway volume impaired the flow of AC power in the cranium and caused windkessel impairment, to which ventriculomegaly is an adaptation. In pseudotumor, venous hypertension affected DC power flow in the capillaries but did not affect AC power or the windkessel, therefore obviating the need for adaptive ventriculomegaly.

CONCLUSIONS

In pseudotumor, the CSF spaces are unaffected and the windkessel remains effective. Therefore, ventricles remain normal in size. In hydrocephalus, the windkessel, which depends on the flow of AC power in patent CSF spaces, is impaired, and the ventricles dilate as an adaptive process to restore CSF pathway volume. The windkessel model explains both ventriculomegaly in obstructive hydrocephalus and the lack of ventriculomegaly in pseudotumor. This model provides a novel understanding of the pathophysiology of disorders of CSF dynamics and has significant implications in clinical management.

Intracranial hypertension and empty Sella from adrenal adenoma and excessive and prolonged steroid usage: a case report

BACKGROUND

There is only one documented case of intracranial hypertension (IH) and empty sella from cortisol-producing adrenal adenoma so far. And IH and empty sella caused by long-term exogenous hypercortisolism has never been reported before. The purpose of this case report is to alert clinicians to glucocorticoid-induced IH.

CASE PRESENTATION

We present retrospectively a 50-year-old woman with cortisol-secreting adrenal adenoma, who progressed to intractable intracranial hypertension and a markedly expanded empty sella due to improper treatment. In 2011, the patient presented with hypertension, lack of cortisol circadian rhythm, low ACTH, a left adrenal adenoma and a partial empty sella, but did not receive low-dose dexamethasone suppression test (LDDST) and 24-h urinary cortisol. In 2014, she exhibited truncal obesity, raised cortisol, LDDST non-suppression, high urinary free cortisol and low ACTH, proving her cortisol-producing adrenal adenoma. She was simultaneously diagnosed with unexplained IH because of papilledema and elevated intracranial pressure, and her partial empty sella changed to a complete empty sella. In 2015, she underwent adrenal adenoma resection. From 2015 to 2018, she kept taking dexamethasone at least 2 mg daily without her doctors' consent. During this period, she developed transient cerebrospinal fluid rhinorrhea, and her empty sella further worsened. After switching to low dose hydrocortisone, her papilledema disappeared completely, but optic atrophy has become irreversible.

CONCLUSIONS

The patient seems to be just an extreme case, but it may reveal and illustrate a general phenomenon: Both cortisol-producing adrenal adenoma and long-term exogenous hypercortisolism could cause varying degrees of elevated intracranial pressure and empty sella. Clinicians should remain vigilant for this phenomenon in patients with cortisol-producing adrenal adenoma or excessive and prolonged steroid usage and give them corresponding examinations to identify this complication.

Idiopathic intracranial hypertension: an illustrated guide for the trainee radiologist

Idiopathic intracranial hypertension is characterized by increased intracranial pressure, headache, and visual perturbations. Although the pathophysiology of idiopathic intracranial hypertension is obscure, several mechanisms have been proposed, such as increased cerebral blood volume, excessive cerebrospinal fluid volume (due to high production or impaired resorption), and inflammatory mechanisms as a likely cause of or contributor to impaired cerebrospinal fluid circulation. It predominantly affects women of reproductive age who are overweight or obese. The most common symptoms are daily headache, synchronous pulsatile tinnitus, transient visual perturbations, and papilledema with visual loss. The main neuroimaging findings are a partially empty sella turcica; flattening of the posterior sclera; transverse sinus stenosis (bilateral or in the dominant sinus); a prominent perioptic subarachnoid space, with or without optic nerve tortuosity; and intraocular protrusion of the optic nerve head. The main complication of idiopathic intracranial hypertension is visual loss. Within this context, neuroimaging is a crucial diagnostic tool, because the pathology can be reversed if properly recognized and treated early.

Anatomic Variation of the Lateral Sinus in Patients With Idiopathic Intracranial Hypertension: Delineation With Black-Blood Contrast-Enhanced MRI

Objectives: The purpose of this study was to describe the peculiar anatomic variations in the lateral sinus and analyze the patterns of cerebrospinal fluid (CSF) drainage by using high-resolution (HR) black-blood (BB) contrast-enhanced magnetic resonance imaging (MRI) in patients with idiopathic intracranial hypertension (IIH).

Methods: Total 33 IIH patients who were found cerebral venous sinus stenosis (CVSS) by MR venography (MRV) were enrolled in this study. HR-BB contrast-enhanced MRI was used to assess the features of anatomical variations in transverse sinus and sigmoid sinus. The development of bilateral sinuses was firstly evaluated, including unilateral hypoplasia with contralateral dominance or bilateral balanced development. Then, four kinds of anatomical variations were eventually recorded, including circumscribed stenosis, arachnoid granulation (AG), fibrous septum (FS), and brain herniation (BH) into dural venous sinus (DVS).

Results: Bilateral venous drainage dysfunction was found in 30(90.9%) patients, whereas only 3(9.1%) patients presented unilateral venous drainage dysfunction. There was no difference in clinical symptoms between the two groups. The most common case is hypoplasia in unilateral sinus combined with anatomic variation in the contralateral dominant transverse sinus such as AG and BH into DVS. Total of 52 anatomic variations were finally found in bilateral sinuses in 33 enrolled patients, including 19(36.5%)AGs, 12(23.1%)FS, 7(13.5%) BH into DVS and 14(26.9%) circumscribed stenoses. Moreover, 41(62.1%) lateral sinuses showed enhancement in T1-weight-enhanced MRI.

Conclusions: Patients with CVSS almost had CSF outflow disorders, whatever bilateral equalization or unilateral hypoplasia with contralateral dominance. Four types of main anatomic variations, including circumscribed stenosis, AG, FS, and BH into DVS, caused venous reflux obstruction by elevating the intracranial press (ICP).

Diagnostic value of brain MR imaging and its correlation with clinical presentation and cognitive functions in idiopathic intracranial hypertension patients

Background

Idiopathic intracranial hypertension (IIH) is a neurological disorder of unknown etiology and ambiguous pathophysiology due to cerebrospinal fluid dysregulation. This study is designed to evaluate the role of brain magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) in diagnosis of IIH, to clarify the nature and extent of cognitive deficits, and to detect if there is a correlation between radiology, clinical findings, and cognitive dysfunctions in those patients.

Results

The study included 34 patients and 34 age-, sex-, body mass index (BMI)-, and education-matched healthy control subjects. MR brain imaging and Montreal cognitive assessment (MoCA) test were used for both groups. MRI and MRV sensitivity for IIH diagnosis were 85.2% and 85.3% with 100% and 94.1% specificity respectively. 44.1% had cognitive impairment, memory was the most affected domain, followed by attention, abstraction, and orientation with statistically significantly lower total MoCA score (p < 0.005). Domain comparisons reveal a statistically significantly lower memory/delayed recall (p < 0.001) and abstract scores (p < 0.007) in IIH cases versus control subjects. In comparing patients with cognitive impairment (CI) versus those without CI, there were statistically significantly higher CI in low education level, presence of diplopia, hormonal contraceptive use, abnormal MRI brain, papilledema grades, BMI, and opening pressure.

Conclusions

Presence of more than or equal 3 MR imaging findings, bilateral transverse sinus stenosis, and less than or equal 4 combined conduit score increase the specificity and sensitivity of MRI and MRV for IIH diagnosis. IIH had detrimental effect on different cognitive domains especially when patient have low education level, diplopia, papilledema ≥ grade III, high OP ≥ 61.5 cm H2O, and BMI ≥ 34 Kg/m2 with abnormal MRI and MRV findings.

Evaluation of the signs and symptoms of pseudotumor cerebri syndrome in pediatric population

PURPOSE

Pseudotumor cerebri syndrome (PTC) is characterized by increased intracranial pressure without a space-occupying lesion and a normal cerebrospinal fluid (CSF) composition without evidence of CSF infection. In this study, we aimed to compare the symptoms, signs, and clinical characteristics of patients presenting with a preliminary diagnosis of pseudotumor cerebri syndrome (PTC) who were diagnosed and not diagnosed with PTC.

METHOD

We conducted a retrospective study of patients who were referred to our clinic with signs and symptoms of PTC. We compared the patients' symptoms, signs, and clinical characteristics who were diagnosed with PTC with those who were not diagnosed with PTC using modified Dandy criteria.

RESULTS

Ninety-four patients with the pre-diagnosis of PTC were included in the study. LP procedure was done in all patients. After LP, 75.3% of the patients were diagnosed with PTC, but 24.7% did not meet the criteria for PTC. A statistically significant relationship was found between the increase in headache complaints when leaning forward, headache that keeps the child from playing, and the CSF pressure level (p = 0.014, p = 0.019; p < 0.05). There was no statistically significant correlation between papilledema and CSF pressure level (p > 0.05). A statistically significant relationship was found between papilledema grade and CSF pressure level (p = 0.038; p < 0.05), and the rate of high CSF pressure in the groups with Grades 2-3 and Grade 4 papilledema was higher than that in the group with Grade 1 papilledema. Cranial nerve 6 palsy (CN6) (p = 0.048) and flattening of the posterior aspect of the globe (FPS) are found independent risk factors (p = 0.004 p < 0.05).

CONCLUSIONS

PTC signs and symptoms show variability among pediatric population.

Increased GFAP concentrations in the cerebrospinal fluid of patients with unipolar depression

Inflammatory processes involving altered microglial activity may play a relevant role in the pathophysiology of depressive disorders. Glial fibrillary acidic protein (GFAP) and calcium-binding protein S100B are considered microglial markers. To date, their role has been studied in the serum and tissue material of patients with unipolar depression but not in the cerebrospinal fluid (CSF). Therefore, the aim of the current study was to examine GFAP and S100B levels in the CSF of patients with major depression to better understand their role in affective disorders. In this retrospective study, 102 patients with unipolar depression and 39 mentally healthy controls with idiopathic intracranial hypertension were investigated. GFAP and S100B levels were measured using commercially available ELISA kits. CSF routine parameters were collected during routine clinical care. The mean values of GFAP and S100B were compared using age (and sex) corrected ANOVAs. Matched subgroups were analyzed by using an independent sample t-test. In addition, correlation analyses between GFAP/S100B levels and CSF routine parameters were performed within the patient group. Patients with unipolar depression had significantly higher levels of GFAP than controls (733.22 pg/ml vs. 245.56 pg/ml, p < 0.001). These results remained significant in a sub-analysis in which all controls were compared with patients suffering from depression matched 1:1 by age and sex (632.26 pg/ml vs. 245.56 pg/ml, p < 0.001). Levels of S100B did not differ significantly between patients and controls (1.06 ng/ml vs. 1.17 ng/ml, p = 0.385). GFAP levels correlated positively with albumin quotients (p < 0.050), S100B levels correlated positively with white blood cell counts (p = 0.001), total protein concentrations (p < 0.001), and albumin quotients (p = 0.001) in the CSF. The significance of the study is limited by its retrospective and open design, methodological aspects, and the control group with idiopathic intracranial hypertension. In conclusion, higher GFAP levels in patients with depression may be indicative of altered microglia activity, especially in astrocytes, in patients with unipolar depression. In addition, correlation analyses support the idea that S100B levels could be related to the integrity of the blood-brain/CSF barrier. Further multimodal and longitudinal studies are necessary to validate these findings and clarify the underlying biological processes.

Pseudotumor Cerebri with Blindness

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

Dural Venous Sinus Stenosis: Why Distinguishing Intrinsic-versus-Extrinsic Stenosis Matters

BACKGROUND AND PURPOSE

Dural venous sinus stenosis has been associated with idiopathic intracranial hypertension and isolated venous pulsatile tinnitus. However, the utility of characterizing stenosis as intrinsic or extrinsic remains indeterminate. The aim of this retrospective study was to review preprocedural imaging of patients with symptomatic idiopathic intracranial hypertension and pulsatile tinnitus, classify the stenosis, and assess a trend between stenosis type and clinical presentation while reviewing the frequencies of other frequently seen imaging findings in these conditions.

MATERIALS AND METHODS

MRVs of 115 patients with idiopathic intracranial hypertension and 43 patients with pulsatile tinnitus before venous sinus stent placement were reviewed. Parameters recorded included the following: intrinsic or extrinsic stenosis, prominent emissary veins, optic nerve tortuosity, cephalocele, sella appearance, poststenotic fusiform enlargement versus saccular venous aneurysm, and internal jugular bulb diverticula. χ² cross-tabulation statistics were calculated and recorded for all data.

RESULTS

Most patients with idiopathic intracranial hypertension (75 of 115 sinuses, 65%) had extrinsic stenosis, and most patients with pulsatile tinnitus (37 of 45 sinuses, 82%) had intrinsic stenosis. Marked optic nerve tortuosity was more common in idiopathic intracranial hypertension. Cephaloceles were rare in both cohorts, with an increased trend toward the presence in idiopathic intracranial hypertension. Empty sellas were more common in idiopathic intracranial hypertension. Cerebellar tonsils were similarly located at the foramen magnum level in both cohorts. Saccular venous aneurysms were more common in pulsatile tinnitus. Internal jugular bulb diverticula were similarly common in both cohorts.

CONCLUSIONS

In this cohort, most patients with idiopathic intracranial hypertension had extrinsic stenosis, and most patients with pulsatile tinnitus had intrinsic stenosis. Awareness and reporting of these subtypes may reduce the underrecognition of potential contributory stenoses in a given patient's idiopathic intracranial hypertension or pulsatile tinnitus.