Pseudotumour Cerebri (Benign Intracranial Hypertension, Intracranial Hypertension)
What is pseudotumour cerebri?
Pseudotumour cerebri occurs when there is a build-up of pressure within the skull without any apparent cause. The symptoms are similar to those associated with a tumour, but there is no mass present. This condition can affect males and females of all ages, but is most commonly found in women who are obese and aged between 20 and 45 years old.
What causes pseudotumour cerebri?
In the majority of cases of pseudotumour cerebri are unknown, but there is a suggestion that some cases are linked to excessive cerebrospinal fluid. This fluid surrounds the brain and the spinal cord and forms a protective barrier against injury. Cerebrospinal fluid is produced by the brain and normally, it is absorbed. If not absorbed properly, this may lead to a build-up that exerts pressure on the brain.
There is also evidence to suggest that the condition may be linked to narrowing of the sinuses in the brain known as the transverse sinuses. However, it is unclear whether this is causative or if it is a result of pseudotumour cerebri.
Several risk factors have been identified for pseudotumour cerebri, including:
- taking some forms of medication, such as tetracycline
- underlying health conditions, including anaemia, Addison’s disease, sleep apnoea, lupus, polycystic ovarian syndrome and under active parathyroid glands
What are the symptoms?
Symptoms of pseudotumour cerebri include:
- headaches and pain behind the eyes, which intensifies when you stare at something
- nausea and/or vomiting
- changes in vision
- impaired peripheral vision
- seeing flashes of light
- temporary bouts of blindness
- ringing in the ears that is in time with your heart beat (this is known as pulsatile tinnitus)
- back and neck pain
Potential complications of pseudotumour cerebri include:
- impaired vision
- deteriorating sight, which may result in blindness
How is pseudotumour cerebri diagnosed?
Before any tests are conducted, your doctor will note down your symptoms, have a look at your medical and family history and carry out a physical examination. Several tests may then be used to try and confirm a diagnosis. These include:
- Eye tests: eye tests assess vision and will flag up any changes since your last test and issues such as blurred or double vision. If a doctor suspects pseudotumour cerebri, the test will be used to check for pressure and inflammation, known as papilladema, on the optic nerve
- An MRI or CT scan
- Lumbar puncture
The results of the tests will be used to confirm a diagnosis and rule out other potential causes. Once the test results are ready, the diagnosis will be discussed with the patient and doctors will explain what happens next and what kinds of treatment options are available.
Treating pseudotumour cerebri
The aim of treatment is to prevent symptoms from getting worse and protect your sight. Most commonly, medication is prescribed and types of drug used include:
- Acetazolamide: this is a drug used to treat glaucoma and it can help to reduce the production of cerebrospinal fluid. It has been found to be effective in around 47-67% of cases
- Diuretics: diuretics can help to reduce the risk of fluid retention by increasing urination
- Painkillers for headaches and migraines
In cases where there is significant swelling around the optic nerve, surgery may be recommended. A procedure called optic nerve sheath fenestration may be carried out to remove excess fluid and improve eye sight.
A procedure to fit a thin tube called a shunt may also be recommended to drain excess cerebrospinal fluid from the bottom of the spine.
If you are overweight or obese, your doctor may recommend losing weight, as obesity is a risk factor and will make symptoms worse. The best way to lose weight is to exercise on a regular basis and eat a healthy, balanced and calorie-controlled diet.