Investigations
You may have a number of investigations as part of your visit, or before your visit, to help us to get the most out of your appointment.
MRI scans
Magnetic resonance imaging (MRI) is a type of scan that produces detailed images of the inside of the body using strong magnetic fields and radio waves.
MRI is used to:
- confirm the diagnosis of NF2
- screen asymptomatic relatives
- assess the growth of tumours
- look for the cause of changing symptoms
- plan surgical procedures and Gamma Knife treatment
- assess response to treatment.
In NF2 we scan the brain and spine of all new patients. Further MRIs are planned according to your individual need.
Hearing test - pure tone audiometry (PTA)
Pure tone audiometry (PTA) tests the hearing of both ears. During PTA, a machine called an audiometer is used to produce sounds at various volumes and frequencies (pitches). You listen to the sounds through headphones and respond when you hear them by pressing a button.
Speech discrimination test
The speech discrimination test, or speech audiometry, involves testing your ability to hear words without using any visual information. Sometimes, you are asked to listen to words while there is a controlled level of background noise.
Eye tests
NF2 can affect different parts of the eye and some people develop visual problems over time. We therefore monitor the eyes carefully.
When your eyes are tested, you may:
- be asked to look in different directions
- have the pressure of your eye checked
- have the front surface of your eye examined
- have your retina examined using a bright light.
Examining the retina
The hole at the front of your eye that increases and decreases in size depending on the light conditions is called the pupil. By looking through your pupil, the ophthalmologist will be able to see a small part of your retina, a light-sensitive layer at the back of your eye.
If the ophthalmologist needs a clearer view of your retina, a procedure known as dilation may be used. This is where eye drops are used to widen your pupil so the whole of your retina can be examined.
The ophthalmologist may use an instrument with a lens and a bright light, called a slit lamp, to examine your eyes. After the examination, your vision may be a little blurry and your eyes will be sensitive to light for a few hours. You should avoid driving for around two to three hours while your eyes remain dilated.
Medical review
Neurological examination
The neurologist at clinic will look for changes or weakness in your eye movements, leg or hand co-ordination, balance, speech and reflexes.
Skin examination
The doctor may look at your skin for pigmentation changes and visual lumps.
Genetic testing
Our genes are our bodies' instructions for how we develop. Genetic testing is used to find out whether a person is carrying a specific gene alteration that causes NF2. This testing can be done using a blood sample, or sample from a tumour, as the cells of both contain our genetic information.
Blood test
We will take a blood test and send it for analysis. The results can take up to three months to come back. It is important to be aware that, even in people with a diagnosis of NF2, we do not always find a gene alteration to explain the diagnosis. This might be because the altered gene is only present in some of a person's cells, or because there may be genetic alterations involved in NF2 that our technology cannot yet detect.
Tumour sample
If you have surgery, we may ask for your consent to send a small sample of tumour for genetic testing.