Idiopathic intracranial hypertension.

Idiopathic intracranial hypertension (IIH) is a condition which affects predominantly overweight women and is characterized by raised intracranial pressure without any identifiable pathology in the brain and with normal cerebrospinal fluid (CSF) composition. The cause of IIH is unclear and as such it remains a diagnosis of exclusion. Although the pathophysiology of IIH remains elusive, some observations have recently been added to our understanding of this, including the presence of transverse sinus stenosis on many patients and the possible role of leptin and inflammation in the disease pathogenesis. Headache is the most common symptom and papilloedema is the major clinical finding. Choices of medical treatment are limited to the use of diuretics particularly acetazolamide and encouragement of weight loss. Surgical therapies such as CSF diversion procedures and fenestration of the optic nerve may be necessary in some cases with persistent symptoms or progressive visual deterioration. While not life-threatening, IIH has a significant morbidity with up to 25% of patients developing visual impairment from optic atrophy. Visual surveillance is therefore vital. Long-term follow-up is recommended as the disease may worsen after an initial period of stability.