Asymptomatic idiopathic intracranial hypertension: Prevalence and prognosis.

BACKGROUND: Little is known about the presentation and prognosis of asymptomatic idiopathic intracranial hypertension (IIH). Papilloedema can be found incidentally on routine fundus examination, with many of these patients actually having symptoms on direct questioning. The aim was to evaluate visual and headache outcomes in people with IIH who present with or without symptoms. METHODS: Prospective observational cohort study, between 2012 and 2021, 343 people with confirmed IIH diagnosis were enrolled in the IIH:Life database. Outcomes such as vision (LogMAR); Humphrey visual field perimetric mean deviation (PMD) and optical coherence tomography (OCT) and headache were evaluated using LOESS (locally weighted scatterplot smoothing) graphs and regression analysis. RESULTS: One hundred and twenty-one people had incidentally found papilloedema, with 36 people with completely asymptomatic presentations. Those with asymptomatic IIH at diagnosis had similar visual prognosis compared to those with symptomatic disease. Sixty-six percent of the asymptomatic cohort became symptomatic during follow-up, and of these the predominant symptom was headache (96%). Headache frequency during follow-up was lower in the asymptomatic cohort. CONCLUSIONS: The prognosis of those with IIH who present with or without symptoms is similar.