This study is a multicenter, prospective, population-based cohort study with consecutive inclusion of patients in which the diagnosis of IIH is suspected. This study is carried out in collaboration between the Danish Headache Center, Rigshospitalet-Glostrup, and the Neurological Department at Odense University Hospital.
Patients are eligible for inclusion into the study if:
1. IIH is suspected
2. \> 18 years old and able to provide written informed consent.
At baseline included patients will have:
A.) Medical history B.) Neurological, ophthalmological and general medical examination C.) Relevant neuro-imaging D.) Blood samples and lumbar puncture F.) Evaluation by other specialist, including neuro-psychologists, if appropriate.
Subsequently patients are divided into three sub-groups according to revised Friedmann criteria:
1. Certain IIH or IIH-WOP
2. Suspected, but unconfirmed, IIH
3. IIH ruled out
Patients are followed at a headache center and by neuro-ophthalmologist according to standard clinical practice.
