Pseudotumor Cerebri

1 What is Pseudotumor Cerebri?

Pseudotumor cerebri (“false brain tumor”) is a condition characterized by increased cerebrospinal fluid pressure in the brain. It is also sometimes known as idiopathic intracranial hypertension (IIH) or benign intracranial hypertension (BIH).

  • Increased pressure inside the skull causes symptoms that are similar to those seen with a brain tumor, including headache and vision problems.
  • A correct diagnosis is important because pseudotumor cerebri may lead to progressive (and possibly permanent) vision loss.
  • Pseudotumor cerebri is more likely to affect women of childbearing age. Other conditions associated with pseudotumor cerebri are obesity, (especially with recent weight gain), use of certain medications, inborn narrowing of the vein that drains blood from the brain and sleep apnea.

2 Symptoms

The most common symptoms of pseudotumor cerebri are headaches and blurred vision. Other symptoms may include:

  • Vision changes (like double vision) or vision loss
  • Dizziness, nausea and/or vomiting
  • Neck stiffness
  • 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

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.

Rarely, patients presenting with increased ICP with related optic nerve edema may be asymptomatic.

Visual symptoms of papilledema may include the following:

  • Transient visual obscurations, often predominantly or uniformly orthostatic
  • Progressive loss of peripheral vision in one or both eyes (nerve fiber layer defects, enlargement of the blind spot)
  • Blurring and distortion (ie, metamorphopsia) of central vision due to macular edema or optic neuropathy
  • Sudden visual loss (eg, fulminant IIH)

Nonspecific symptoms of IIH may include dizziness, nausea, vomiting, photopsias, and retrobulbar pain.

3 Causes

The exact cause of pseudotumor cerebri in most individuals is unknown, but it may be linked to an excess amount of cerebrospinal fluid within the bony confines of your skull.

Most cases of IIH occur in young women who are obese; a considerably smaller percentage occurs in men who are otherwise healthy. Patients with higher body mass indexes (BMIs) and recent weight gain are at increased risk.

If IIH presents in an individual who is not overweight, it is necessary to rule out associated risk factors, such as the following:

  • Exposure to or withdrawal from certain exogenous substances (eg, drugs)
  • Systemic diseases (including Lyme disease)
  • Disruption of cerebral venous flow
  • Certain endocrine or metabolic disorders

Exogenous substances reportedly associated with IIH include amiodarone, antibiotics (eg, nalidixic acid, penicillin, and tetracycline), carbidopa, levodopa, chlordecone, corticosteroids (topical and systemic), cyclosporine, danazol, growth hormone, indomethacin, ketoprofen, lead, leuprolide acetate, levonorgestrel implants, lithium, oral contraceptives, oxytocin, perhexiline, phenytoin, and vitamin A (100,000 U/day) /retinoic acid.

The following systemic diseases have been reportedly associated with IIH:

The various endocrine risk factors that have been confirmed in epidemiologic studies include the following:

  • Female sex
  • Reproductive age group
  • Menstrual irregularity
  • Obesity
  • Recent weight gain
  • Pregnancy

Endocrine risk factors that meet minimal criteria but have not been confirmed in case-controlled studies include the following:

4 Making a Diagnosis

Diagnosis of pseudotumor cerebri 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

Eyes:

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.

5 Treatment

Treatment for pseudotumor cerebri depends on underlying etiology causing the disease. The following measures might be helpful:

  • Weight loss,
  • 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.

6 Risks and Complications

Complications and sequelae of Pseudotumor Cerebri include:

  • Galactorrhoea-Hyperprolactinaemia,
  • Headache,
  • Papilloedema,
  • Raised Intracranial Pressure,
  • Optic Atrophy,
  • 3rd Cranial Nerve Disorder,
  • Anisocoria,
  • Nausea and Vomiting,
  • Diplopia, Binocular,
  • Hypertension, Systemic,
  • Reduced Level of Consciousness,
  • Acute Confusional State,
  • 6th Cranial Nerve Disorder,
  • Sinus Bradycardia,
  • Respiratory Failure Type 2,
  • Cheyne-Stokes Respirations,
  • Mydriasis,
  • Chronic Brain Failure.
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