Abstract WP109: Idiopathic Intracranial Hypertension and the Risk of Incident Ischemic Stroke

Introduction: Idiopathic intracranial hypertension (IIH) is a rare cause of headache that is associated with several adverse health outcomes. A recent study demonstrated an association between IIH and ischemic stroke (IS) in a large European cohort, after accounting for obesity and other cardiovascular risk factors. Given the well-established relationship between migraine and stroke, we sought to use US population-level data to further explore the association between hospitalization for IS and IIH as well as with migraine with and without aura. Methods: We conducted a retrospective cohort study using statewide administrative claims data encompassing emergency department presentations and inpatient hospitalizations from the Healthcare Cost and Utilization Project across 11 states between 2016 and 2021. Patients with IIH (primary cohort) or migraine (comparison cohort) were identified using validated ICD-10-CM codes. The primary study endpoint was hospitalization for IS, also defined using validated codes, after an initial headache diagnosis. Cox regression models assessed the association between IIH and IS after adjustment for demographics and cardiovascular risk factors (including obesity). Results: We identified 11,861 patients with diagnoses of IIH and 862,209 patients with diagnoses of migraine. In comparison to patients with migraine, patients with IIH were younger, more often female and of a non-White race, and had higher rates of comorbid hypertension, diabetes, atrial fibrillation, coronary artery disease, congestive heart failure, obstructive sleep apnea, and obesity. During a median follow-up time of 3.3 years, 11 patients (0.09%) with IIH were hospitalized for IS, compared to 534 patients (0.06%) with migraine. Multivariable Cox regression analysis did not demonstrate a significant association between IIH and incident IS (adjusted HR 1.43, 95% CI, 0.79–2.61). Conclusion: Although IIH and migraine had similar rates of incident IS in a large nationally representative US cohort, we found no association between IIH and IS after adjustment for cardiovascular risk factors. The relationship between IIH and incident stroke requires further exploration.