Contents
Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, formerly called benign intracranial hypertension, is a condition with raised intracranial pressure (ICP) in the absence of identifiable cause.
- Primarily affects young obese women in the childbearing years
History:
Quincke in 1897 reported the first cases of IIH shortly after he introduced the lumbar puncture into medicine. It was named pseudotumor cerebri in 1904 but was not well delineated clinically until the 1940’s when cerebral angiography was added to pneumoencephalography to identify cases of cerebral mass lesions. Foley coined the term benign intracranial hypertension in 1955 but reports from the 1980’s demonstrated a high incidence of visual loss and the term “benign” is no longer appropriate.
Presentation
Headache (M/C symptom):
Severe daily pulsatile headaches
Pulse synchronous tinnitus
Pulsatile tinnitus
Visual symptoms:
- Transient visual obscurations (monocular/binocular transient blurred vision lasting < 30s)
- Diplopia (due to CN VI paresis)
- Papilledema and associated loss of
sensory visual function

Diagnosis
Modified Dandy diagnostic criteria for IIH:
- Symptoms and signs of increased ICP
- No localizing neurologic signs, except for unilateral/bilateral CN VI nerve palsies
- Increased CSF opening pressure, but normal CSF composition
- No evidence of hydrocephalus, mass, structural, or vascular lesion on imaging
- No other cause of increased ICP identified

Ophthalmoscopic examination:
- Papilledema (optic disc edema) due to increased intracranial pressure (CARDINAL SIGN)
- Ocular motility disturbances:
- Horizontal diplopia (33% cases)
- CN VI palsies (10-20% cases)
- Visual acuity (decreased only in severe/long-standing cases)
- Perimetry: Visual field loss (almost all cases)
MRI:

Lumbar puncture:
- ↑ CSF opening pressure
- Normal CSF characteristics
Management

Weight reduction
M/imp step
Carbonic anhydrase inhibitors:
Decrease CSF production and thereby decrease ICP, leading to improved symptoms and signs of IIH
- Acetazolamide
- Topiramate
Loop-diuretic: Furosemide
Lower intracranial pressure
Surgical management:
When other treatments have failed to prevent progressive vision loss or when the disease onset is fulminant
- CSF diversion (e.g., ventriculo-peritoneal and lumbo-peritoneal shunting)
- Optic nerve sheath fenestration (ONSF)