Idiopathic intracranial hypertension is not idiopathic: proposal for a new nomenclature and patient classification

With advancements in our understanding of the relationship between venous sinus pressures and intracranial pressures, the term ‘idiopathic intracranial hypertension’ no longer adequately describes the disease process for which it is named, nor does it help stratify the heterogenous group of patients that suffer from it. Venous manometry in patients with this condition clearly demonstrates elevated intracranial venous pressures as the cause of elevated intracranial pressures. I propose the term ‘chronic intracranial venous hypertension syndrome’ as a better descriptor for the disease and then present a potential classification scheme for patients based upon the pathophysiology causing the venous hypertension. Idiopathic intracranial hypertension (IIH) was first described as pseudotumor cerebri by Dandy in 1937 as a clinical syndrome composed of headaches and visual obscurations combined with elevated intracranial pressure and no obvious mass lesion.1 This nomenclature later would be changed to ‘benign intracranial hypertension,’ however IIH clearly does not always have benign behavior as patients may present with visual loss that can progress to fulminant blindness. According to the Oxford Medical Dictionary, “idiopathic” is defined as: “Relating to or denoting any disease or condition which arises spontaneously or for which the cause is unknown.” Through history, afflictions that had no clear inciting or contributing cause (and therefore were perceived to develop spontaneously) were labeled with the term ‘idiopathic.’ Often times these diseases were diagnoses of exclusion, whereby the disease was defined by a subset of observed clinical criteria but more importantly by the absence of other, more common, better understood pathologies. The ‘wastebasket’ that is the diagnosis of exclusion is therefore a summation of ‘unknowns’ that may, in fact, represent separate, clinically-distinct entities beyond the resolving power of current medicine. The endless goal of medical research is to further understand disease to reduce the suffering it causes. It is only …