Prevalence of new-onset migraine in patients with idiopathic intracranial hypertension in comparison to the general population

Background: Idiopathic intracranial hypertension (IIH) encompasses patients with elevated intracranial pressure (ICP). Generally, it is difficult to make a differential diagnosis between IIH and co-existing migraine headaches. Thus, this article intends to estimate the prevalence of migraine in patients with IIH and explain the occurrence of new-onset migraine after the diagnosis of IIH. Methods: The case group included 108 patients with IIH referred to the neurology wards of three university hospitals. A random sample of controls (n = 103) were recruited from patients hospitalized in the surgery and orthopedics ward. A checklist for migraine diagnosis was filled out. Cerebrospinal fluid (CSF) pressure and presence or absence of papilloedema (PE) in the patients and any necessary data were also recorded from the inpatient medical documents. All statistical analyses were done by SPSS software. Results: There were 70 (64.80%) and 22 (21.40%) migraineurs in the case and control groups, respectively, and the difference was found to be significant (P < 0.001). In 26 (37.14%) migraine cases in the IIH group, the disorder was diagnosed after developing IIH. Also, there was a past medical history of having migraine in 44 (62.85%) migraineurs. In the fully adjusted regression models, the odds of being affected by migraine in patients with IIH was 6.17 times greater than the controls [odds ratio (OR) = 7.15, 95% confidence interval (CI) = 3.56-14.36, P < 0.010]. The patients’ mean CSF opening pressure was 32.10 ± 1.03 cmH2O and 93 (81.60%) subjects were found to have PE. Conclusion: It was demonstrated that subjects with IIH might have about a 6-time higher likelihood of developing migraine headache than the general population. These considerations can help prevent misdiagnosis of migraine headache as the recurrence of IIH or uncontrolled IIH and subsequent inappropriate management.