Idiopathic intracranial hypertension.

Idiopathic intracranial hypertension results from cerebral oedema. The symptoms and signs of the condition are reviewed, especially the risks of visual failure if the condition is prolonged without adequate treatment. The most significant symptom in childhood is headache, and the most important sign is papilloedema. The difficulties of diagnosis are discussed, especially the cerebral oedema that can occur on the withdrawal of steroid therapy, and the increased intracranial pressure that may develop with minimal forms of craniostenosis. The causes of intracranial hypertension are many, and include ear infections, venous sinus thrombosis, the use of certain drugs, and as a complication of acute disseminated encephalomyelitis and Cushing's disease, and impaired renal function. The condition may remit spontaneously, but even so a careful watch must be kept on visual acuity. If treatment is needed various drugs can be tried, and if the response is unsatisfactory repeated lumbar punctures will be indicated. It is rarely necessary to consider surgical intervention such as cerebral decompression.