Idiopathic intracranial hypertension – is it really idiopathic?

11th December 2025, A/Prof Chee L Khoo

We all have a handful of patients witth idiopathic intracranial hypertension. It is often diagnosed by someone else incidentally. While the full pathophysiology of the condition is still not clear, we know enough about the condition to know who may be at highest risk and perhaps, diagnose the condition early to prevent visual loss. Medical treatment is possible in the early stages and cerebrospinal fluid (CSF) shunting is no longer the only surgical options. Headaches is the most common initial symptom but we see so many patients with headaches that we don’t find a cause for. Who may have IIH? Which patients with headaches should we be on the lookout for IIH? 

Max Nonne, a German neurologist, described a syndrome of headache accompanied by swollen optic disks in patients with CSF pressure back in 1904 (1). He called the condition “pseudotumor cerebri,” because it behaves like a tumour but none of these patients have a tumour. He described a clinical syndrome of chronically elevated intracranial pressure of unknown aetiology.…