When is ‘idiopathic intracranial hypertension’ no longer idiopathic?

Treatment is different and while IIH carries the risk of permanent visual loss, VST has a mortality rate of 10%-30%, as well as complications with high morbidity such as seizures and cerebral infarction. 9 10 Although VST may complicate spontaneous intracranial hypotension 11 and the finding of VST in patients inappropriately labelled as idiopathic intracranial hypertension is well reported, we could not find any papers describing VST being found after an accurate diagnosis of idiopathic intracranial hypertension. Iliac vein stenosis is an independent risk factor for developing deep vein thrombosis in young women-for every 1% increase in stenosis there is a small but significant rise in risk. 14 Subjects with >70% stenosis of the iliac vein, who were also on the combined oral contraceptive pill, had an OR of 17 for the development of a deep vein thrombosis. 14 If the same is true for venous sinus stenosis: patients with IIH are likely to be at a higher risk of VST.