Headache Phenotypes in Idiopathic Intracranial Hypertension and Its Short-Term Outcomes: A Retrospective Case Series Study

Background: Idiopathic intracranial hypertension (IIH) presents a complex physiopathology, leading into diverse manifestations, notably variable headache phenotypes. Furthermore, its frequent overlap with migraine complicates the evaluation of treatment benefit for IIH-related headache. Our aim was to investigate if there is any relationship between demographic factors, clinical patterns of headache, treatment response, and headache short-term outcome with the headache phenotype of IIH. Methods: This study was a retrospective analysis of demographic, clinical, and treatment features of patients with idiopathic intracranial hypertension presenting with headache and evaluation of headache outcomes in the first 12 months following treatment. Results: Thirty-two patients were included (median age of onset 29.0 years (interquartile range 25.0 - 38.5), 90% females, median body mass index 32.5 kg/m²; 87.5% (n = 28) with papilledema; median cerebrospinal fluid opening pressure 36.5 cm H₂O). Patients presented with migraine (n = 11, 34.4%), tension-type (n = 9, 28.1%), or a not-classifiable headache (n = 12, 37.5%). Regarding treatment and shortterm follow-up (12 months), there was a failure of medical treatment in 43.8% (n = 14) and a reduction of headaches (> 50%) in 62.5% (n = 20) of the patients. Among headache phenotypes, there were no significant differences regarding demographics, clinical features, clinical patterns, or treatment response at baseline. Also, there were no differences regarding response to treatment or headache outcomes in 1, 3, 6, and 12 months of follow-up. Conclusions: In our study, migraine and unclassifiable types were the most commonly reported headache phenotypes. Headache phe- notype does not appear to be an essential factor in allowing clinical distinction, treatment response, or predicting the short-term headache outcome of this intriguing entity.