Neuroimaging features of idiopathic intracranial hypertension persist after resolution of papilledema

Background: Papilledema is a key clinical finding in the diagnosis of idiopathic intracranial hypertension (IIH). However, newly proposed criteria allow diagnosis without papilledema only if certain neuroimaging features are present, and it is currently unclear if these findings persist upon resolution of papilledema and intracranial hypertension. We performed an exploratory study to assess whether or not these neuroimaging changes persist after resolution of papilledema. Methods: A retrospective chart review identified three groups of patients (6 per group) who had received orbital imaging within 4 weeks of fundoscopic examination: 1) IIH patients without active papilledema, 2) IIH patients with active papilledema, and 3) patients with no history of IIH or papilledema. All magnetic resonance imaging (MRI) scans were reviewed and graded by a neuroradiologist who was blinded to clinical status. Neuroimaging features were compared by nonparametric rank testing using the Kruskal–Wallis one-way analysis of variance. Results: Measurements of sellar and optic nerve configuration (including globe flattening and optic nerve protrusion) showed a statistical trend with papilledema status. For the control group versus the active papilledema group, the values were 0.0597 and 0.0621, respectively. For the control group versus the resolved papilledema group, the values were 0.0485 and 0.0512, respectively. However, globe and sellar p-values for the resolved papilledema group versus the active papilledema group were not significant, 1.000 and 0.6023, respectively. Conclusions: Some of the characteristic neuroimaging features of IIH, specifically sellar and globe configuration, suggest a statistical trend for persistence after papilledema has resolved and intracranial pressure (ICP) has normalized. Careful clinical correlation and fundus examination is essential because some of these neuroimaging features can be seen in normal patients and those with resolved IIH, and their presence on MRI may not necessarily indicate active disease or elevated ICP.