Idiopathic intracranial hypertension (pseudotumor cerebri)
Idiopathic intracranial hypertension (formerly pseudotumor cerebri) is raised intracranial pressure of unclear cause, without a mass lesion or hydrocephalus, occurring mainly in obese women of childbearing age and presenting with headache, papilledema, and visual symptoms. Diagnosis requires an elevated lumbar puncture opening pressure with normal CSF and normal or empty-sella imaging; treatment centers on weight loss and acetazolamide to protect vision, with surgery reserved for medically refractory disease.
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What this article covers
- Overview
Definition: idiopathic intracranial hypertension (IIH), previously called pseudotumor cerebri, is a syndrome of elevated intracranial pressure occurring in the absence of a mass lesion, hydrocephalus, or vascular cause on neuroimaging.
- Epidemiology
Demographic predominance: approximately 90% of affected individuals are women of childbearing age with an elevated body mass index.
- Risk factors
Obesity in a woman of childbearing age: the dominant epidemiologic risk factor.
- Pathophysiology
CSF dynamics mismatch: the leading proposed mechanism is impaired resorption of CSF at the arachnoid granulations relative to its rate of production, producing sustained elevation of intracranial…
- Clinical features
Headache: the most common presenting symptom; nonspecific in character and may resemble tension-type headache or migraine, often present daily.
- Differential diagnosis
Cerebral venous sinus thrombosis: can produce an identical clinical picture of raised intracranial pressure with papilledema; distinguished by a filling defect on magnetic resonance venography, which…
- Diagnosis
Diagnostic confirmation: the modified Dandy criteria require signs and symptoms of raised intracranial pressure (papilledema is the key objective sign), a lumbar puncture opening pressure greater…
- Management
First step: confirm the diagnosis and obtain baseline formal visual field testing before starting treatment, since subsequent visual field trends will guide escalation of therapy.
- Complications
Permanent visual loss: the principal feared complication, from sustained papilledema causing irreversible optic nerve axonal injury; can progress to blindness if untreated.
- Prognosis
Generally favorable with treatment: most patients maintain useful vision with timely diagnosis, weight loss, and medical therapy.
- Prevention
Sustained weight management, targeting a meaningful reduction in body mass index rather than any specific target number, is the principal preventive strategy for both initial disease and recurrence…
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