Venous sinus stenting worsening in fulminant intracranial hypertension secondary to Cryptococcus gattii: lessons learnt.

Idiopathic intracranial hypertension (IIH) is a diagnosis of exclusion, and venous sinus stenosis may coexist with IIH, making careful evaluation for secondary causes essential. We report an immunocompetent man in late 30s who presented with headache and visual blurring. Brain MRI demonstrated features of raised intracranial pressure with transverse sinus stenosis. Lumbar puncture revealed high opening pressure and IIH was presumed. The patient underwent left transverse-sigmoid sinus stenting with transient improvement, followed by recurrent headache and rapid visual deterioration. Repeat angiography demonstrated new venous narrowing, prompting stent extension. Re-evaluation of cerebrospinal fluid cultures grew Cryptococcus gattii on Sabouraud dextrose agar. Induction therapy with amphotericin B plus flucytosine, followed by fluconazole maintenance, resulted in complete resolution of headache. This case highlights that C. gattii meningitis can mimic IIH, and that cerebrospinal fluid cryptococcal evaluation is essential before confirming a diagnosis of IIH or proceeding with venous sinus stenting.