- benign intracranial hypertension
Pseudotumor cerebri is a syndrome associated with increased intracranial pressure (pressure within the skull), headache and frequently with visual loss. The cause of the most common form of this syndrome is unknown.. Symptoms of this disorder can mimic brain tumor (thus the name pseudo-tumor). This condition occurs more frequently in young, obese females (although it can occur in males and females of any age).
What is going on in the body?
The most common form has no known cause and is known as idiopathic pseudotumor cerebri. This form will be the focus of this article.
Symptomatic pseudotumor cerebri is less common and is secondary to an identifiable cause such as cerebral vein disease, medication effect, infection, inflammatory disease, or spread of cancer to the lining of the brain.
What are the causes and risks of the condition?
The main risk of the condition is permanent visual loss.
What can be done to prevent the condition?
Because the cause is unknown, idiopathic pseudotumor cerebri can not be prevented. However, with early diagnosis and treatment, permanent visual loss can usually be prevented.
How is the condition diagnosed?
A thorough history and physical examination is required. This will usually be followed by imaging studies such as cranial CT scans or cranial MRIs are done to rule out a brain tumor. A spinal tap, or withdrawal of cerebrospinal fluid using a thin needle, will reveal increased intracranial pressure. If enough fluid is removed, the headache will often be relieved, further confirming the diagnosis. However, the spinal tap should not be done until a CT scan has shown that the increased intracranial pressure (ICP) is not due to a brain tumor or other space-occupying mass in the brain.
Long Term Effects
What are the long-term effects of the condition?
If not properly treated, the person may continue to experience the symptoms mentioned above. The most feared long-term effect is permanent visual loss.
What are the risks to others?
There are no risks to others.
What are the treatments for the condition?
The condition may be treated either medically or surgically. Sometimes a combination of the two may be necessary. If the problem is caused by a medication such as oral contraceptives, the medication will be stopped. Other medical treatments or recommendations include:
- weight loss (the most important)
- diuretics, or "water pills", to remove excess fluid from the body
- headache medications (usually over-the-counter formulations suffice)
- spinal tap to remove excess fluid from the brain relieving pressure
- ventriculoperitoneal shunt (shunt to remove brain/spinal fluid from within the brain usually into the abdomen to relieve the pressure)
- optic nerve sheath fenestration (a surgical procedure where the sheath is cut to allow seepage of fluid out of the brain to relieve pressure )
What are the side effects of the treatments?
Pain medications and diuretics may cause allergic reactions, stomach upset, and salt imbalance. Surgery can be complicated by bleeding, infection, or an allergic reaction to the anesthetic.
What happens after treatment for the condition?
With weight loss, the condition may resolve completely. Diuretics often work quickly , but their effectiveness may wane. Ventriculoperitoneal shunt placement relieves symptoms, but most malfunction over time and eventually need to be replaced. Unfortunately, for those requiring aggressive treatment such as optic nerve sheath fenestration, the condition often returns after a year or so following surgery.
How is the condition monitored?
The syndrome is monitored through regular eye examinations, preferably by an ophthalmologist. Weight control and menstrual cycles are monitored on a regular basis through physical examinations. Any new or worsening symptoms should be reported to the healthcare professional.
The Merck Manual, 17th Edition; Current Medical Diagnosis&Treatment 2000.