UMEM Educational Pearls

Category: Neurology

Title: The Rising Incidence of Idiopathic Intracranial Hypertension

Keywords: Idiopathic intracranial hypertension, IIH, pseudotumor cerebri, obesity, healthcare utilization (PubMed Search)

Posted: 3/10/2021 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

  • Idiopathic intracranial hypertension (IIH) predominantly affects women of childbearing age and is strongly associated with obesity.
  • Patients can have high rates of healthcare utilization due to their chronic disabling headaches, multiple diagnostic tests and specialist consultations, and potential complications related to treatments.
  • A recent study looked at trends in the incidence, prevalence, and healthcare outcomes of IIH in the 3.1 million Welsh population over a 14-year period.
    • Incidence of IIH increased from 2.3/100,000 to 7.8/100,000 (p<0.001).
    • Prevalence of IIH increased from 12/100,000 to 76/100,000 (p<0.001).
    • Obesity (BMI >30 kg/m2) also increased from 29% to 40% of the population (p<0.001), with IIH incidence and prevalence strongly associated with BMI.
    • Outcomes included blindness (0.78%), moderate visual impairment (1.9%), CSF diversion (9%) with 44% of these patients requiring at least 1 revision surgery.
    • IIH patients also had 5.28 times higher rate of unscheduled hospital visits during this time period.

Bottom Line: The incidence and prevalence of IIH is increasing, likely related to rising rate of obesity. This has also been associated with more healthcare utilization compared to the general population.



  • Miah L, Strafford H, Fonferko-Shadrach B, et al. Incidence, prevalence, and health care outcomes in idiopathic intracranial hypertension. Neurology. 2021;96:e1251-1261.
Follow me on Twitter @EM_NCC