1. To establish the correlation between the evolution of the body mass index in benign intracranial hypertension and the response to treatments.
2. To establish the BMI at which this disease occurs.
3. To establish how much the BMI must be reduced to cure this disease.
4. To assess the evolution and response to treatments of sick people who DO NOT reduce or even continue to increase their BMI despite treatment with Acetazolamide or a possible CSF diversion

There is unanimity that one of the causes of benign intracranial hypertension is obesity. However, there is no agreement on the upper limit of BMI above which this disease occurs or the lower limit above which it is cured. People affected by this disease often have extreme difficulty losing weight and it is not uncommon for them to have followed various diets over the years to lose weight. In general, patients prefer to take medication or to undergo surgery with the implantation of a cerebrospinal fluid diversion system that does not force them to sacrifice following a strict diet. Unfortunately, those who do not manage to lose weight noticeably present repeated complications due to malfunction of the CSF diversion system with headaches and a progressive loss of visual acuity. Among other reasons, it must be considered that cerebrospinal fluid diversion systems work by pressure gradient. Since obesity increases the pressure inside the peritoneal cavity, these shunt systems will be ineffective because they will not be able to drain even if the pressure of the shunt valve is diminished to levels below 6 mm Hg.

The aim of this study is to find out what the specific BMI goal should be for each patient in particular and to be able to make them aware of this so that they make an effort and achieve it. Patients are referred to Endocrinology to be recommended the diet to follow. In some cases, bariatric surgery is used. Still, as it does not require effort or awareness on the part of these people, it is not uncommon for them to gain weight again and for benign intracranial hypertension to recur. The usual thing is that their evolution is torpid and the repeated therapeutic attempts are fruitless or plagued by complications. Weight loss using medication such as Ozempic (Semaglutide) is not accepted internationally nor contemplated by the Endocrinology Service of the General University Hospital of Valencia. On the one hand, it has no indication and on the other hand, the possible complications are not known. In addition, patients who take it on their own initially lose weight, but when they stop taking the medication they quickly regain the lost weight as a result of not having adopted healthy eating habits.

Inclusion Criteria:

• Adults aged 18 years and older at the time of enrollment. There is no upper age limit to ensure inclusivity across age ranges.
• A confirmed diagnosis of Idiopathic Intracranial Hypertension, established according to the Dandy criteria.
• The diagnostic process must exclude other potential causes of increased intracranial pressure as detailed in the 'Diagnosis' section, ensuring an accurate identification of idiopathic cases.

Exclusion Criteria:

• A diagnosis other than IIH, specifically: tension-type headache, Chiari I malformation, or any other headache disorder unrelated to IIH.
• The presence of secondary causes of increased intracranial pressure (e.g., structural brain abnormalities, venous sinus thrombosis, or medication-induced factors).

This study is designed to be a retrospective-prospective cohort study. Data was collected from all retrospective patients attended in the last 10 years by the Neurosurgery department at Hospital General Universitario de Valencia who presented idiopathic intracranial hypertension (IIH) and were accepted to participate. Data were extracted and reviewed from the patient's medical records.