The terms “pseudotumour cerebri”1 and “benign intracranial hypertension”,2 respectively introduced by Nonne in 1904 and Foley in 1955, were originally applied to patients with raised intracranial pressure in whom no tumour was found and whose course was benign (table 1). But the natural history proved to be not always benign. Buchheit et al,3 finding progressive visual loss in several patients, challenged the terms “benign” and “pseudotumour” in 1969: “The syndrome is neither a benign process nor a false tumour.” The terminology was then changed to “idiopathic intracranial hypertension”.3, 4

In an excellent monograph, Johnston and colleagues5 drew attention to some of the earliest possible examples of the syndrome which had been recorded in a long section on diseases of the optic nerve in the Transactions of the Ophthalmological Society UK 1880–1881. This was before the introduction of lumbar puncture (see below) so it was impossible to measure intracranial pressure. Papilloedema was then usually referred to as optic neuritis. For example, Hughlings Jackson mentioned reports by ophthalmologists of “…a recoverable optic neuritis in young women suffering from uterine derangement”.6 Gowers too in 1881 described optic neuritis associated with “chlorosis”, most often caused by nutritional iron deficiency anaemia7 but his account is not typical of idiopathic intracranial hypertension. Broadbent reported in the same issue of the BMJ, a 12-year-old girl with a 2 year history of headache and vomiting with “double optic neuritis” associated with amenorrhoea whose symptoms resolved and menstrual regularity was restored although she remained blind from …