Pseudotumor Cerebri (Idiopathic Intracranial Hypertension, IIH)
Pseudotumor cerebri (idiopathic intracranial hypertension, IIH) is a disorder of raised intracranial pressure occurring without a mass lesion or hydrocephalus. It is characterized by headache, visual disturbance and papilledema, and is most common in young women with obesity.
Última actualización: 2026-06-06
Definition
IIH is defined by elevated intracranial pressure in the absence of a brain tumor, hydrocephalus or other structural intracranial lesion. The name 'pseudotumor' (false tumor) reflects the fact that its symptoms — headache, papilledema and visual disturbance — mimic a brain tumor. The disorder is benign, but if untreated it can lead to permanent vision loss.
Epidemiology and Risk Factors
It is rare in the general population but markedly more common in women of reproductive age (roughly 20-45 years) with obesity, with a high female-to-male ratio. The strongest risk factor is obesity and rapid weight gain. Other associated factors include pregnancy, certain medications (vitamin A derivatives, tetracycline-class antibiotics), polycystic ovary syndrome and obstructive sleep apnea. Secondary causes such as venous sinus thrombosis must be excluded before the diagnosis is made.
Pathophysiology
The exact mechanism is not fully understood and is multifactorial. The most widely accepted view is that pressure rises because of impaired absorption of cerebrospinal fluid (CSF). In obesity, increased intra-abdominal pressure impairs venous return, raising intracranial venous pressure and hindering CSF absorption. Some patients have narrowing of the transverse venous sinuses; whether this narrowing is a cause or a consequence of the disease is debated.
Symptoms
The most common symptom is headache, typically daily and worse in the morning, which can worsen with coughing or straining; it is often accompanied by pulse-synchronous ringing in the ear (pulsatile tinnitus). Visual symptoms are important: transient visual obscurations lasting seconds with positional change, constriction of the peripheral visual field, and double vision from sixth cranial nerve involvement. The most critical finding is bilateral papilledema on fundoscopy; untreated chronic papilledema can cause optic atrophy and permanent vision loss.
Diagnosis
Diagnosis rests on the modified Dandy criteria. Contrast-enhanced brain MRI and MR venography are mandatory to exclude structural lesions and venous sinus thrombosis; IIH-specific findings such as an empty sella, posterior globe flattening and transverse sinus narrowing may be seen. Lumbar puncture shows an elevated CSF opening pressure (above 25 cmH2O in the lying position) with normal CSF composition. Ophthalmologic assessment is mandatory: visual acuity, papilledema grading, visual fields (perimetry) and follow-up with optical coherence tomography (OCT).
Treatment
The goal of treatment is to lower intracranial pressure, resolve papilledema and prevent permanent vision loss. The most effective treatment is weight loss; losing 5-10% of body weight markedly improves symptoms in most patients, and bariatric surgery may be considered in refractory cases. The first-line medication is acetazolamide, which reduces CSF production; topiramate is an alternative or adjunct. Surgery is required in refractory cases such as progressive vision loss, refractory severe papilledema or treatment-resistant headache: optic nerve sheath fenestration to preserve vision, a CSF shunt (VP or LP) when headache and vision loss coexist, and venous sinus stenting in selected cases of venous narrowing.
Prognosis
With early diagnosis, weight loss and appropriate medical therapy, most patients improve markedly and often achieve full remission. However, recurrence can occur if weight is not controlled. In untreated or late-diagnosed cases, permanent vision loss and, in a small number, blindness can develop; regular ophthalmologic follow-up is therefore critical. Headache usually improves, but may become chronic in a proportion of patients. Outcomes are individual and none can be guaranteed.
Referencias
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:955-970.
- NORDIC Idiopathic Intracranial Hypertension Study Group; Wall M, McDermott MP, Kieburtz KD, et al. Effect of acetazolamide on visual function in patients with idiopathic intracranial hypertension and mild visual loss: the IIHTT randomized clinical trial. JAMA. 2014;311(16):1641-1651.
- Mollan SP, Davies B, Silver NC, et al. Idiopathic intracranial hypertension: consensus guidelines on management. J Neurol Neurosurg Psychiatry. 2018;89(10):1088-1100.
Este artículo es informativo y no sustituye un examen médico. Las decisiones de diagnóstico y tratamiento son individuales.