Idiopathic intracranial hypertension

Previously “Benign” Intracranial Hypertension but not entirely benign…

Intracranial hypertension but with normal CSF, and no ventriculomegaly. Presents with usual symptoms of early morning headache, effortless vomiting. VI nerve palsy may be seen, rarely II/IV. Papilloedema is often the first clue.

No sex differential prepubertally, not associated with obesity (contrary to popular belief).

Normal CSF opening pressure is 7.5cm of water <2yr, 13.5 <5yr, 20 over 5yr. Lumbar puncture is therapeutic; 2 step tap procedure is usually used if opening pressure is over 30cm. NB General anaesthetic can give false pos result! Secondary causes include drugs, endocrine conditions.

Since repeated LP is unpleasant, medical therapy can be considered. Topiramate is probably equivalent to the more usual acetazolamide (a diuretic). Steroids should be used for malignant hypertension (ie where there is rapid progression). Any of these treatments may result in a low pressure headache.

Surgical options include Optic nerve sheath fenestration, lumbar-peritoneal shunt.