The prevalence of idiopathic intracranial hypertension and associated co-morbidities in central western new south wales (nsw)

Objectives Over the last 20 years we have been surprised by the large number of patients seen with idiopathic intracranial hypertension (IIH) in Central Western NSW. We therefore performed a study to quantitate the prevalence of this condition. This is the first epidemiological study of IIH performed in Australia and one of the first to investigate a rural population worldwide. The primary objective was to identify the prevalence of IIH in Central Western NSW. Secondary objectives included identifying the prevalence of IIH subtypes, true and venogenic, identifying the prevalence of co-morbidities amongst these patients and reviewing clinical outcomes. Methods The representative population comprised five areas within Central Western NSW defined by postal code. Retrospective analysis was conducted from the two neurology practices in the region. Data collected from patient files included patient demographics, presenting symptoms, imaging results, co-morbidities, treatments received and clinical outcomes. Prevalence was calculated using 2011 census data (2016 data being unavailable). Results We found an overall prevalence of 24.9 per 100 000, with 7.9 true and 17 venogenic. All participants identified were female. A large proportion of individuals were either overweight or obese. The most common co-morbidities amongst IIH patients were migraine (31·8%), depression (30%) and hypertension (22.7%). Overall 81.2% of patients reported symptomatic improvement (75% true and 85.7% venogenic). Of those, 33.3% received stenting (all were patients with venogenic IIH) while 66.7% improved with medical management alone (50% true and 50% venogenic). Conclusions We have identified a higher prevalence of IIH in Central Western NSW compared with the previously reported UK prevalence of 10.9 per 100 000. This disorder is also highly prevalent in obese females thus clinicians should have a high index of suspicion in any obese female patient with headache. Although the majority of patients experience symptomatic relief, randomised controlled trials of treatment modalities are needed.