Objective To observe intracranial pressure in women with idiopathic intracranial hypertension who follow a low energy diet. Design Prospective cohort study. Setting Outpatient department and the clinical research facility based at two separate hospitals within the United Kingdom. Participants 25 women with body mass index (BMI) >25, with active (papilloedema and intracranial pressure >25 cm H 2 O), chronic (over three months) idiopathic intracranial hypertension. Women who had undergone surgery to treat idiopathic intracranial hypertension were excluded.

The cause of idiopathic intracranial hypertension (IIH) remains unknown, and no consensus exists on how patients should be monitored and treated. Acetazolamide is a common treatment but has never been examined in a randomised controlled trial. The objectives of this pilot trial are to prospectively evaluate the use of acetazolamide, to explore various outcome measures and to inform the design of a definitive trial in IIH. Fifty patients were recruited from six centres over 23 months and randomised to receive acetazolamide (n = 25) or no acetazolamide (n = 25). Symptoms, body weight, visual function and health-related quality-of-life measures were recorded over a 12-month period. Recruited patients had typical features of mild IIH and most showed improvement, with 44% judged to have IIH in remission at the end of the trial. Difficulties with recruitment were highlighted as well as poor compliance with acetazolamide therapy (12 patients). A composite measure of IIH status was tested, and the strongest concordance with final disease status was seen with perimetry (Somers' D = 0.66) and optic disc appearance (D = 0.59). Based on the study data, a sample size of 320 would be required to demonstrate a 20% treatment effect in a substantive trial. Clinical trials in IIH require pragmatic design to involve sufficiently large numbers of patients. Future studies should incorporate weighted composite scores to reflect the relative importance of common outcome measures in IIH.

The appearance of the optic disc is a key measure of disease status in idiopathic intracranial hypertension (IIH). The Frisén classification describes stages of optic disc swelling (grades 0-5). It is the only classification of papilloedema, and is used internationally in clinical and research practice. Despite this, there has been very limited evaluation of the scale. We assessed the inter-rater reproducibility and ability to discriminate optic disc changes over time using the Frisén classification compared with a system of ranking papilloedema severity in patients with IIH. Paired disc photographs (before and after treatment) were obtained from 47 patients with IIH (25 acute and 22 chronic). Six neuro-ophthalmologists blinded to patient identity, clinical information and chronology of the photographs reviewed the discs and allocated a Frisén grade and ranked the paired discs in order of papilloedema severity (disc ranking). A total of 188 optic disc photographs were reviewed. All six reviewers agreed in only three comparisons (1.6%) when using the Frisén classification, compared with 42 comparisons (45.2%) when using disc ranking. The probability of agreement between any two reviewers was 36.1% for Frisén grade and 70.0% for disc ranking. Disc ranking had significantly greater sensitivity for finding differences in degree of disc oedema, identifying a difference in 75.3% of paired photographs compared to 53.2% detected using the Frisén classification (p < 0.001). This study demonstrated the limited reproducibility and discriminative ability of the Frisén classification in identifying changes in serial optic disc photographs in IIH. Simple optic disc ranking appears to be a more sensitive and reliable tool to monitor changes in optic disc appearance. The use of disc ranking in clinical practice and research studies is recommended to monitor alterations in optic disc appearance until alternative schemes, specific to IIH, have been developed.

Aim: To document the causal association of iron deficiency anaemia (IDA) and intracranial hypertension (IH). Methods: A consecutive case note review of patients with a clinical diagnosis of idiopathic intracranial hypertension (IIH) and anaemia presenting to a tertiary referral unit over a 2.5-year period. Demographics, aetiology and clinical details were recorded and analysed. Results: Eight cases were identified from 77 new cases presenting with IIH. All 8 had documented microcytic anaemia with clinical evidence of raised intracranial pressure. There was no evidence of venous sinus thrombosis on MRI and MR venography in 7 subjects and on repeated CT venography in 1. On correction of anaemia alone, 7 cases resolved. One patient with severe progressive visual loss underwent ventriculoperitoneal shunt in addition to treatment of anaemia, with good outcome. The incidence of this association is 10.3%. Conclusion: These cases present an association between IDA and IH, in the absence of cerebral sinus thrombosis. As a clinically significant proportion of cases presenting with signs of IIH have IDA, we recommend all patients presenting with IIH have full blood counts and if they are found to be anaemic, they should be treated appropriately.

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