Idiopathic Intracranial Hypertension: Epidemiology, pathophysiology, clinical features and contemporary management.

Abstract

Idiopathic Intracranial Hypertension (IIH) is a syndrome of increased intracranial pressure (ICP) without evident cause. The exact pathogenesis of IIH remains elusive but it is also plausible that the syndrome represents the common final pathway of several different mechanisms. IIH has an estimated incidence of 1-3 per 100 000 and a predilection for obese women of childbearing age.  Presentation involves symptomatology and semiology of elevated intracranial pressure with headache being the most common. Visual disturbances can be devastating, progressive and may result in permanent visual loss. Moreover, pulsatile tinnitus is frequently encountered. However, asymptomatic presentations are also not uncommon with patients diagnosed after routine ophthalmological examination illustrates papilledema. Diagnosis is based upon the Friedman’s criteria. Absence of hydrocephalus or mass lesion and normal cerebrospinal fluid (CSF) composition need to be confirmed. Several treatment modalities have been suggested, varying from non-surgical (weight loss, drugs such as acetazolamide, serial lumbar puncture) to interventional and surgical (CSF diversion procedures, optic nerve sheath fenestration (ONSF), endovascular venous sinus stenting, or even bariatric surgery). There are very few RCTs to critically assess these therapies and, consequently, no consensus on the optimal management of IIH.