Idiopathic Intracranial Hypertension in the Northwest of Northern Ireland: Epidemiology and Clinical Management

Background: There is limited literature on the epidemiology of idiopathic intracranial hypertension (IIH). The diagnosis and management of IIH require a multidisciplinary approach. We sought to study the incidence as well as prevalence of IIH and to evaluate the current management of IIH in the northwest of Northern Ireland. Methods: Medical records of patients diagnosed with IIH between 2007 and 2014 in a general hospital in Northern Ireland were reviewed. Clinical and outcome data were retrieved. Results: There were 45 patients with IIH, 44 women: 1 man. The mean age at presentation was 29.4 (SD 9.8) years and mean body mass index (BMI) 39.8 (SD 9.5) kg/ m2. All patients had neuroimaging, 44 (98%) had CT/MR venogram and 41 (91%) had visual perimetry. The crude incidence of IIH was 2.36 per 100,000 (95% CI 1.65-3.37). For women, the incidence was 4.65 per 100,000/year (95% CI 3.25-6.66). The prevalence was 14.3 per 100,000 overall (95% CI 9.72-20.9) but 28.1 per 100,000 in women (95% CI 19.2-41.2). Visual field defects were identified in 25 of 41 (61%); 4 patients (9%) required shunting procedures. At follow-up, the mean BMI decreased by 1.6 kg/m2 (p = 0.024). Conclusions: The incidence of IIH in the northwest of Northern Ireland is among the highest ever reported and probably reflects the known increase in obesity.