Abstract text (incl. figure legends and references)

Question: Is there any relationship between demographic factors, clinical pattern of headache, treatment response, and headache outcome with the headache phenotype of IIH?

Methods: Retrospective analysis of demographic and clinical characteristics of patients with IIH presenting with headache between 01/01/2008-31/12/2021, with the evaluation of headache outcomes in the first 12 months following IIH treatment. Statistical analysis was made using descriptive and non-parametric tests.

Results: Headache was present in 32 of 40 patients (80%) with IIH (90% female; mean age 32 years; mean BMI 32,9Kg/m²; 88% with papilledema; mean CSF opening pressure 37cmH₂0). Patients presented commonly with migraine (n=11, 34.4%) and tension-type headache (n=7, 28.1%). A not-classifiable phenotype was present in 12 patients (37.5%). Associated symptoms included photophobia (47%), worsening with Valsalva/recumbency (25%), nausea/vomiting (19%), and phonophobia (9%). 72% of patients had daily pain, but only 9% had a medication-overuse headache; 41% had previous primary headache (mostly migraine). Regarding treatment and short-term follow-up (12months), there was a failure to medical treatment in 44% and a reduction of headaches (≥50%) in 63% of the patients. Among headache phenotypes, there were no significant differences regarding age, race, BMI, or clinical features (symptoms associated with IIH, CSF opening pressure, clinical pattern of headache, time until diagnosis). Also, there were no differences regarding response to treatment or headache outcomes in 12 months follow-up.

Conclusions: Headache phenotype 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.