Evolving evidence in adult idiopathic intracranial hypertension: pathophysiology and management

Abstract

Idiopathic intracranial hypertension (IIH) is a rare but important disease associated with significant morbidity. There is an expected rise in prevalence in line with the escalating global burden of obesity. Modern revisions in the terminology and diagnostic criteria for IIH help guide clinicians in investigations and researchers in standardising recruitment criteria for clinical trials. The pathophysiology of IIH is incompletely characterised; suggested underpinning mechanisms include the role of cerebrospinal fluid regulation as well as metabolic and endocrinological perspectives. Recent treatment trials are providing insights into the management but debate still surrounds key areas in treatment. This review will provide an up-to-date discussion on the potential pathogenic mechanisms and management of IIH.

Neuroendovascular Cerebral Sinus Stenting in Idiopathic Intracranial Hypertension

“…IIH is a disorder of poorly understood pathophysiology that is progressive in nature; permanent vision loss is found in 25% of cases and 1–2% of new cases each year are registered blind [5]. Recently, several groups have been investigating this pathophysiology by undertaking catheter studies in the venous sinuses (cerebral venography) and recording intra-sinus pressures (manometry).…”

“…Once papilledema has been diagnosed, brain imaging has a central role in excluding space-occupying lesions, obstructive hydrocephalus, and cerebral venous thrombosis. MRIs of the head and orbits with intravenous contrast and MR/CT venography should be performed [5]. The most commonly observed radiological signs of raised ICP are an empty sella, flattening of the posterior globes at the insertion of the optic nerves, protrusion of the optic nerve head into the vitreous, tortuosity of the intraorbital optic nerve, and demonstration of sinus stenosis on MR venography.…”

“…All mandatory tests of visual function should be recorded, including visual acuity, color vision, pupil examination, a dilated eye examination to document the optic nerve head, and macular findings to exclude an ocular cause of bilateral disc edema [5]. Quantification of disc edema is done using optical coherence tomography, which permits high-resolution noninvasive cross-sectional imaging of the neurosensory retina.…”

Evaluating the Fat Distribution in Idiopathic Intracranial Hypertension Using Dual-Energy X-ray Absorptiometry Scanning

“…2 IIH has a striking phenotype of young, obese women of childbearing age. 2,3 There is clearly a strong association between the condition and obesity, which is seen in over 90% of IIH patients, 3 and weight loss has been shown to resolve symptoms and improve clinical parameters of IIH. However, not all obese patients develop IIH, and it is not known whether the pattern of body fat distribution could contribute to development of disease.…”

What Do Transgender Patients Teach Us About Idiopathic Intracranial Hypertension?

“…1 There is also a recognised subset of patients where papilloedema is not present, IIH without papilloedema (IIHWOP). 2 The condition has a predilection for obese women of childbearing age, 3 yet the reasons for this are not clear. 4 …”