Pseudotumor Cerebri: What You Need to Know
Pseudotumor cerebri (PTC), also known as idiopathic intracranial hypertension, is a problem caused by elevated cerebrospinal fluid pressure in the brain.
Because this condition causes symptoms of elevated pressure in the head – which is also seen with large brain tumors – but have normal scans, the condition has been called pseudotumor cerebri, meaning “false brain tumor”.
Pseudotumor cerebri symptoms include headache and blurred vision, which can increase over time.
Prompt diagnosis and treatment of pseudotumor cerebri is important since it may lead to progressive (and possibly permanent) loss of vision.
What Is Pseudotumor Cerebri?
The fluid that surrounds the spinal cord and brain is called cerebrospinal fluid or CSF. Cerebrospinal fluid supplies the brain and spinal cord with nutrients and removes impurities while protecting and cushioning these delicate structures.
Normally, after circulating, CSF is reabsorbed into the body through blood vessels. But if too much fluid is produced or not enough is re-absorbed, the CSF can build up and cause pressure within the skull, which is an enclosed space.
This pressure can cause symptoms similar to those of a brain tumor, including worsening headache and vision problems. Untreated pseudotumor cerebri can result in permanent problems such as vision loss.
Pseudotumor Cerebri Symptoms
The most common are headaches and blurred vision. Other symptoms may include:
Vision changes (like double vision) or vision loss
Dizziness, nausea and/or vomiting
Persistent ringing in the ears (tinnitus)
Forgetfulness and/or depression
Since exertion can increase pressure inside the skull, symptoms can become worse with exercise or physical activity.
Pseudotumor cerebri symptoms may resemble those of many other medical problems. Always consult an experienced specialist for a diagnosis.
Pseudotumor Cerebri Headache
Headaches associated with this disorder may vary from person to person. Often, pseudotumor cerebri headaches often occur at the back of the head and start as a dull pain, which tends to be worse at night or first thing in the morning.
Common headaches such as migraine or tension headaches can coexist with pseudotumor cerebri, which can complicate the diagnosis. Doctors are likely to diagnose these frequently seen disorders until a more detailed examination or further testing reveals PTC.
Vision problems in pseudotumor cerebri evolve slowly over time, with temporary episodes of visual blurring that can start in the peripheral field of vision. If the pressure continues to build up, the nerves affecting eye movement can also be affected causing double vision.
The individual may not even notice until later in the clinical course of the disorder when the central field of vision is involved and the symptoms become constant. At this point there is a growing risk of blindness.
Other Pseudotumor Cerebri Symptoms
Pseudotumor cerebri can also cause a ringing in the ears called pulsatile tinnitus, characterized by a rhythmic rushing sound in the ears that matches the person’s heartbeat.
It is increasingly recognized that PTC can also affect memory and cognition.
Risk Factors for Pseudotumor Cerebri
Although experts don't know why this condition develops, here are other conditions that are commonly seen in people with the disorder:
Female sex: Women are nine times more likely to have pseudotumor cerebri than men. The role of hormones is not understood.
Excess weight: Body weight is the most significant preventable pseudotumor cerebri risk factor, although thin people can develop the disorder.
Certain medications: Use of lithium, tetracyclines, certain steroids and vitamin A derivatives may predispose people to pseudotumor cerebri.
Blood vessel irregularities: Some people are born with a narrowing of the vein that drains blood and CSF from the brain, resulting in increased pressure.
Sleep apnea: Sleep apnea is an increasingly common sleep disorder that is associated with pseudotumor cerebri.
Diagnosis of Pseudotumor Cerebri
Diagnosis involves ruling out other health problems including an actual brain tumor. A physical exam and a few tests can help identify pseudotumor cerebri and rule out other causes for pressure inside the skull. The tests include:
Brain imaging such as MRI or CT scans
A lumbar puncture (spinal tap) to confirm the elevated pressure (normal is less than 25 cm) and withdraw a sample of fluid from around the spine for testing to exclude infectious and inflammatory causes of raised pressure.
Exam to test eye function
Because elevated intracranial pressure affects the eyes, a careful eye exam and testing of the visual fields is crucial to determine the risk of vision loss. An eye exam may reveal optic nerve swelling at the back of the eye, an abnormality called papilledema.
Imaging of the Skull
A CT scan may appear normal or may reveal smaller than normal fluid spaces in the brain (ventricles) of cerebrospinal fluid.
MRI scans may be normal or may show small ventricles or a flattened pituitary gland, both of which indicate building pressure in the skull. The studies may also show narrowed draining veins or indirect signs of abnormally elevated spinal fluid pressure.
Testing Intracranial Pressure
Once imaging tests have ruled out any tumors or other abnormalities, the doctor will assess the pressure of the cerebrospinal fluid to verify the diagnosis. A (spinal tap) helps confirm the elevated pressure and also excludes infectious and inflammatory causes of elevated intracranial pressure.
The fluid drainage can give some individuals immediate, but temporary, relief of their headache and other symptoms, but this response alone, without signs of elevated pressure or eye problems, is not conclusive evidence that pseudotumor cerebri is the problem.
Pseudotumor Cerebri Treatment
Treatment depends on what is causing the fluid to build up inside the skull. The doctor might recommend any combination of the following:
Limiting fluids or salt in the diet
Medications, such as diuretics, which help the body to get rid of extra fluid
A spinal tap to remove fluid and reduce pressure
Surgical placement of shunt, or special tube, to redirect fluid from the brain and ease pressure
Surgery to decompress increased CSF around the optic nerve
Placement of a stent in the draining venous sinuses if narrowed, to improve CSF absorption and reduce intracranial pressure.
In addition, the doctor is likely to recommend regular checkups to help monitor the person’s symptoms and screen for any underlying problems. Follow-up is important since it is possible for symptoms to recur after treatment.