An Introduction to Neurofibromatosis Type 2
Neurofibromatosis (NF) is a collective name for a group of genetic conditions in which benign (non-cancerous) growths or tumours affect the nervous system. Neurofibromatosis occurs all over the world and affects men and women equally.
There are two types of Neurofibromatosis: NF1 and NF2. This information refers to NF2 only.
NF2 is a genetic disorder that is caused by a misprint in a single gene on Chromosome 22. The misprinted gene will be present at birth but signs of the condition do not usually appear until the teenage years, twenties or later. NF2 may be passed on from parent to child at the time of conception, or it may start in a family with no previous history of the disorder.
A person who has NF2 has a 50% (or 1 in 2) chance of passing on the condition to each of his/her children. NF2 is a variable and unpredictable condition affecting different people in different ways.
Almost everybody who has NF2 develops benign tumours called vestibular Schwannomas (formerly called acoustic neuromas) which grow on both hearing nerves. Each of these nerves has two parts. The cochlear nerve carries iNFormation about sound and the vestibular nerve carries iNFormation about balance, to the brain.
Over time these tumours are likely to cause deafness. A tumour on one side may grow at a different rate from the one on the other side. The size of the tumours may bear little relationship to the degree of deafness. For example a small tumour may produce deteriorating hearing whilst a large tumour may only cause minimal hearing loss. Other benign tumours associated with nerves inside the body may occur, in particular: Of the lining of the brain (meningiomas) On the spine (meningiomas, schwannomas) On the skin (schwannomas) Cataracts are often present from an early age but may not cause significant problems with vision.
How Does NF2 Affect You?
Most NF2 tumours are slow growing and may cause minimal problems for years. Although they are not malignant (not cancerous) their position may produce significant symptoms.
The most common first symptoms of NF2 are: gradual hearing loss tinnitus (ringing or roaring in the ears) unsteadiness, particularly when walking on uneven ground or in the dark These symptoms are caused by tumours on the hearing nerves (vestibular Schwannomas).
Other symptoms may relate directly to the pressure caused by tumours on the spine or on the lining of the brain. For example: headaches change in vision change in sensation, pain or weakness of an arm or leg While the problems in NF2 can be worrying, treatments are improving and support is available through the various doctors and therapists who you may be in contact with.
What Treatments Are Available For NF2?
It is very important to have a detailed discussion with a specialist who is familiar with NF2, to find out about the various options that may be available and to consider the benefits and risks of any operation or treatment.
You will need regular examinations to check hearing and neurological function. Scans of the brain and spine, balance tests as well as eye examinations may be needed annually. The timing of any surgery to remove tumours should be carefully considered. Not every tumour seen on scans needs to be removed. Some NF2 tumours may show very little growth over many years.
Treatments are based mainly on the symptoms the patient describes, alongside results of physical examinations, scans and hearing tests. Operations to remove the tumours on the hearing nerves (vestibular Schwannomas) should be performed by an Ear, Nose and Throat surgeon and/or Neurosurgeon with special expertise in NF2.
The treatment of vestibular Schwannomas will depend on: the size of the tumours whether they are pressing on the brain as well as on the hearing nerve how rapidly they are growing how much hearing loss the tumours have caused Some people choose to have X-ray treatment rather than an operation. The gamma knife or stereotactic surgery shrinks the vestibular Schwannomas. This treatment does have risks and should only be undertaken after discussion with doctors who are familiar with NF2 and its management.
Whichever option is chosen it is difficult to treat a vestibular Schwannoma without causing damage to the hearing nerve and subsequent deafness. Sometimes damage to other nerves, which are close to the hearing nerve, is unavoidable. Most people who become deaf through NF2 learn to lip read very well. Some people can now be offered an auditory brainstem implant (ABI) to help with hearing after surgery. The ABI does not give a return of hearing but gives an awareness of certain environmental sounds and is an aid to lipreading. This new treatment is only available in Specialist NF2 Centres.
If it becomes necessary to have other NF2 tumours removed – on the spine, skin or lining of the brain, the operations are usually more straightforward and carry fewer risks.
For further information, we can put you in touch with a NF Specialist Advisor in your region. They are there to provide support, information and advice, not only for those who have NF2 but also for the family and professionals concerned with your care.
For further information we have a range of literature which can be ordered by calling 020 8439 1234.
The NF - Improving the lives of those affected by Neurofibromatosis