Long term outcomes of idiopathic intracranial hypertension: Observational study and literature review

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Highlights

  • Long term visual and symptomatic outcomes of idiopathic intracranial hypertension (IIH) are excellent.

  • A significant portion of patients in this cohort discontinued treatment due to adverse effects of medication.

  • A small but significant portion of patients have severe vision-threatening disease which requires surgery.

Abstract

Background

Idiopathic intracranial hypertension (IIH) is an unexplained increase in intracranial pressure often associated with obesity. The aim of this study was to conduct a retrospective observational study of the long term clinical, visual, and treatment outcomes in IIH patients.

Methods

A retrospective observational study of patients diagnosed with IIH over a 12-year period at a single centre was completed via database review. Demographic data, symptoms at baseline and last visit, treatments undertaken, and duration of follow-up were included. Visual outcomes, including visual acuity, colour vision, 30-2 Humphrey automated perimetry data, and retinal nerve fibre layer thickness (RNFL), were collected at baseline and last visit.

Results

IIH was diagnosed in 132 patients (90.9 % female) with a median of 2.8 years (range: 0–9.1) follow-up. Mean BMI was 35.9 ± 7.9 kg/m2. Symptoms at presentation were headache (87.6 %), pulsatile tinnitus (27.2 %) and transient visual obscurations (27.2 %). First-line management was acetazolamide in 86.4 %, with 34.2 % of these patients ceasing treatment because of adverse events. Visual field measures and RNFL at last follow-up improved when compared to baseline (median MD: − 1.99 dB (IQR −3.6 to −0.9) to −0.85 (−2.1 to 0.0) (p < 0.001), median RNFL: 132 μm (IQR 116 – 183) to 103 (92 – 113) (p < 0.001)). Some patients (6.1 %) required surgery for more severe IIH.

Conclusions

Long-term symptomatic and visual prognosis in IIH patients is excellent. However, a subset of patients with more severe disease require surgical intervention. Adverse events of treatment lead to high medication discontinuation rates.

Introduction

Idiopathic intracranial hypertension (IIH) is a debilitating condition that predominantly affects obese young women of child-bearing age [1,2]. The pathophysiology of IIH remains poorly characterized [3]. The most common clinical symptoms of IIH include headaches, transient visual obscurations (TVOs), pulsatile tinnitus, and diplopia [3]. Medical treatment options include acetazolamide and topiramate [3]. Weight loss in this condition is beneficial [[4], [5], [6]]. In medically refractory cases, surgical interventions such as optic nerve sheath fenestration (ONSF), cerebrospinal fluid (CSF) diversion procedures, or venous sinus stenting can be considered [7,8].

A subset of IIH cases can be reoccurring and severe, requiring ongoing treatment [9,10]. It follows that an understanding of the long-term outcomes of IIH is crucial to minimise potential but serious visual loss. The aim of this study was to assess the long-term visual and symptomatic outcomes of patients diagnosed with IIH.

Section snippets

Methods

This study was a retrospective observational chart review of all patients diagnosed with IIH at Auckland District Health Board (ADHB), Department of Ophthalmology from June 2005 to March 2017. Patients who met the revised modified Dandy criteria for IIH were included [11]. This included patients with signs and symptoms of raised intracranial pressure (ICP) such as papilledema, neuroimaging (computerised tomography with venography (CTV) or magnetic resonance imaging with venography (MRV))

Results

Data were analysed from 132 patients who met the inclusion criteria. Patient baseline characteristics and follow-up information is reported in Table 1. Patients were young (28.1 ± 9.7 years), and mostly females (90.9 %). Body mass index (BMI) data were available for 124 out of 132 patients (93.9 %) (Table 1). Mean BMI was 35.9 ± 7.9 kg/m2. Only 9 patients (6.8 %) (2/9 were men) had a normal BMI of 20–24.9 kg/m2 based on World Health Organisation obesity grades [14]. CSF opening pressure at

Discussion

This study is one of the largest studies (>100 patients) of IIH patients with follow-up longer than one year. Our key findings are that treatment of IIH results in significant resolution of symptoms: headache reduced by nearly half (87.6 % vs 48.8 %), TVO decreased from 27.2 % vs 7.4 %, and diplopia from 16.5 % vs 0.8 %. However, medical treatment is associated significant adverse events and morbidity. One-third (34.2 %) of patients started on acetazolamide discontinued the medication due to

CRediT author statement

Helen Danesh-Meyer: Conceptualization, Methodology. William Xu: Data curation, Analysis Zak Prime: Data curation, Analysis. Taras Papchenko: Conception, Analysis. All authors were involved in the writing and editing process of this manuscript.

Funding statement

This project was supported by a University of Auckland Faculty of Medical and Health Sciences Scholarship

Ethics committee approval: NZ Health and Disability Ethics Committee.

Declaration of Competing Interest

On behalf of all authors, the corresponding author states that there is no conflict of interest.

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