Pseudotumor Cerebri Support Group

Idiopathic intracranial hypertension (IIH), sometimes called benign intracranial hypertension (BIH) or pseudotumor cerebri (PTC) is a neurological disorder that is characterized by increased intracranial pressure (ICP), in the absence of a tumor or other diseases affecting the brain or its lining. The main symptoms are headache, pulsatile or pulse-synchronous tinnitus, double vision and visual loss. Diagnosis requires brain scans and lumbar puncture. There are various medical and surgical treatments.

Characteristic symptoms of IIH are headache in 94%, transient visual obscurations or transient visual loss in one or both eyes usually lasting seconds (68%), pulse synchronous tinnitus (a "wooshing noise" in the ear) (58%) double vision (38%), and visual loss (30%).

If untreated, complete loss of vision is possible. While IIH may develop in any age group and in both males and females, it is more likely in females of fertile age (15-45) who are overweight or obese. Certain medications (hormonal contraception, vitamin A, tetracycline antibiotics) may increase risk of IIH.

Physical findings in IIH are characterized by papilledema, loss of visual acuity and visual fields, and absence of focal neurological findings (e.g. face, arm or leg weakness, sensory disturbance or coordination loss). Diplopia (double vision), if present, may be due to abducens nerve palsy (the sixth cranial nerve). Absence of papilledema, while making IIH less likely, is possible. The primary goal in treatment of IIH is the prevention of visual loss and blindness. IIH is treated mainly through the attempted reduction of CSF pressure and, where applicable, weight loss. IIH may resolve after initial treatment, may go into remission and relapse at a later stage, or may continue chronically. If the intracranial hypertension is secondary to medication, these need to be discontinued.

CSF pressure may be temporarily decreased by repeated "therapeutic" (as opposed to diagnostic) lumbar punctures (to remove excessive cerebrospinal fluid). However, this is generally regarded as a "holding measure" until medical or surgical treatment has been instituted.

The best studied medical treatment is the carbonic anhydrase inhibitor acetazolamide, which reduces CSF production. Other drugs such as furosemide and various diuretics, and topiramate may be used in an attempt to reduce ICP. The long-term use of corticosteroids to treat chronic IH has fallen out of favor, unless there is a secondary inflammatory process caused by an underlying disease like lupus or Behcet disease. While corticosteroids may lower intracranial pressure in the short-term, the drawbacks to steroids include weight gain, fluid retention and a rebound in intracranial pressure during the drug?s withdrawal.

Surgical treatments include optic nerve sheath decompression and fenestration. In this procedure, a slit is made in the sheath of the optic nerve, which can alleviate swelling and slow or halt loss of vision. Optic nerve sheath fenestration is less effective in controlling the CSF pressure (and in controlling most symptoms, such as headache), but is more effective in protecting the optic nerve from the effects of pressure.

Shunting is a neurosurgical procedure to facilitate the drainage of excess CSF (thereby reducing ICP). A shunt is essentially a silicone tube inserted somewhere in the fluid spaces of the central nervous system, which then drains CSF to the circulatory system or one of the body cavities. There are various types and configurations of shunts; lumboperitoneal (LP) shunts drain from the lumbar spine to the peritoneal cavity, while ventriculoatrial (VA) shunts run from the cerebral ventricles to the heart. Although shunts can dysfunction due to occlusion, infection, malfunction, etc., they are very effective in normalizing CSF pressures. The absence of papilledema or longstanding symptoms make successful shunting less likely. Studies have shown that shunting procedures are becoming more common as the rate of severe obesity rises.

In cases of severe obesity, gastric bypass surgery has been shown to lead to a marked improvement in symptoms.