Unilateral Optic Nerve Sheath Fenestration in Idiopathic Intracranial Hypertension: A 6-Month Follow-Up Study on Visual Outcome and Prognostic Markers

Management and Outcome of Pregnancy in Patients With Idiopathic Intracranial Hypertension: A Prospective Case Series Study

Background and Objectives

Idiopathic intracranial hypertension (IIH) is a syndrome of increased intracranial pressure without an identifiable cause that mostly affects obese persons of childbearing age. In this prospective case series, we have evaluated the overall outcome of pregnancy and birth in participants with IIH and their newborn children. We also provide a proposal for the management of pregnant persons with IIH.

Methods

In this observational study, neuro-ophthalmological findings, the course of IIH-related symptoms, disease management, and pregnancy outcomes were evaluated. The participants were divided into 3 groups according to the course of the disease during pregnancy: stable, worsened, and new diagnosed. Furthermore, the type of delivery and outcome of newborn children such as gestational age, weight at birth, and the presence of asphyxia were compared between the groups.

Results

We observed 47 pregnancies in 42 participants; 2 had spontaneous abortions. There were 19 (47%) participants in the stable, 18 (45%) in the worsened, and 3 (8%) in the new diagnosed groups, respectively. A relapse of IIH occurred in 2 (5%). Worsening of IIH-related symptoms was experienced by 18/37 (49%) participants: headache by 17/18 (94%), tinnitus by 11/18 (61%), and vision by 7/18 (39%) (mostly in the first and second trimester). In 8/18 (44%), the symptoms were transient or alleviated in the second and third trimester. Body mass index before and after pregnancy did not significantly differ among the groups. A total of 8 participants were treated with acetazolamide. The frequency of cesarean section was 17/40 (43%). Preterm delivery occurred in 22%. No increased risk of asphyxia was observed, and all infants, but one, were healthy.

Discussion

Worsening of headache, tinnitus, and/or vision were experienced by half of pregnant participants with IIH, mostly transient in the first and second trimester, rarely required specific treatment, and were not identified as a relapse of IIH. There was no difference in gestational age and weight at birth in children among the groups, and no perinatal asphyxia was noted. Weight gain in the participants was not identified as a risk factor for relapse of IIH in pregnancy. The rate of cesarean and preterm delivery was higher than in the non-IIH population. A proposal for the management of IIH in pregnancy is provided.

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

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

Optic nerve sheath fenestration for visual impairment in cerebral venous diseases

Objective

Visual impairment is the most common clinical feature of cerebral venous sinus occlusion or cerebral venous thrombosis-induced intracranial hypertension, which can result in optic atrophy, leading to irreversible vision loss, visual field defections, and finally, permanent blindness. Papilledema is a typical early pathophysiological alteration in visual impairment. Optic nerve sheath fenestration (ONSF) has become increasingly accepted as an option to prevent or halt progressive visual loss owing to its low risk and complications. The objective of this study is to review the latest research progress on ONSF for the treatment of visual impairment related to cerebral venous diseases.

Methods

Study were searched following PRISMA guidelines based on three electronic databases (Pubmed, Embase and Medline-Ovid). We used the following keywords and variations as keywords to identify studies: "optic nerve sheath fenestration, papilledema, cerebral venous diseases, cerebral venous stenosis, cerebral venous thrombosis, idiopathic intracranial hypertension". The publication date of studies was restricted between 1,872.1.1 and 2,021.12.31. The application of ONSF in papilledema due to cerebral venous diseases is reviewed. Additionally, the common surgical approaches as well as advantages and disadvantages are also described graphically.

Results

With the improvement of specific details of the ONSF procedure and surgical instruments, complications of ONSF have reduced and its safety has been significantly improved, although the number of clinically investigated cases in the literature remains low.

Conclusion

We recommend that ONSF should be considered as an imperative alternative to reduce or delay the visual morbidity of cerebral venous diseases, although there is yet no consensus on the optimal surgical timing.

Idiopathic Intracranial Hypertension from Benign to Fulminant: Diagnostic and Management Issues

Idiopathic intracranial hypertension (IIH) primarrily affects obese women of childbearing years and is commonly associated with headaches, pulsatile tinnitus, and vision changes. Though most patients have a "benign" course, it can lead to significant morbidity, including blindness. The treatment approach is based on severity of visual impact and includes weight loss, intracranial pressure lowering medications, and sometimes surgery, such as spinal fluid diversion, optic nerve sheath fenestration, or venous sinus stenting. More studies are needed to determine when surgery is most appropriate and which surgical procedure provides maximal benefit with the least risk.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

Awareness, Diagnosis and Management of Idiopathic Intracranial Hypertension

The diagnosis and management of idiopathic intracranial hypertension (IIH) can be difficult and multiple medical subspecialities are often involved. Several national and international guidelines regarding the investigations and management of IIH have been published in recent years but still there is no consensus about the optimal organization of IIH-care. The objective of this review was to propose and describe a referral pathway and an organization scheme for diagnosis and management of IIH. An extensive search of existing literature was conducted and summarized. In total, 237 IIH-articles were identified and hereof 43 included. The clinical practice in our specialized IIH-clinic is characterized and described. We conclude that an educational campaign involving medical care providers and patients with chronic headaches is necessary. A detailed organizational proposal for a referral pathway and management of IIH patients based on the literature search and our clinical experience from a highly specialized IIH outpatient clinic is suggested and discussed.