Neurofibromatosis type 2 is a genetic disorder that causes benign tumors to grow in the nerve tissue of the brain , spinal cord, and meninges . One of the benign tumors that often arise due to neurofibromatosis type 2 is vestibular schwanoma or acoustic neuroma.
Neurofibromatosis type 2 (NF2) is less common than neurofibromatosis type 1 . NF2 generally occurs in every one of 25,000 births and can occur due to heredity.
Symptoms of type 2 neurofibromatosis usually begin to appear in your 20s. Symptoms that often appear are hearing loss, ringing in the ears, and balance disorders.
Causes of Type 2 Neurofibromatosis
Neurofibromatosis type 2 is caused by a genetic abnormality on chromosome 22 or the NF2 gene. Chromosome 22 or the NF2 gene functions to produce merlin or schwannomin proteins. This genetic disorder causes the production of merlin protein to be disrupted. This causes uncontrolled growth of nerve cells.
The exact cause of this gene mutation is not yet known. However, children whose father or mother have neurofibromatosis type 2 have a 50% risk of developing the disorder.
The disorder can also occur randomly without a family history of NF2. This condition is called mosaic NF2 . Children with mosaic NF2 generally experience milder symptoms.
Symptoms of Type 2 Neurofibromatosis
Neurofibromatosis type 2 (NF2) will cause the growth of benign tumors on nerve cells. Tumor growth can occur on any nerve. There are several types of tumors that can arise due to NF 2, namely:
- Acoustic neuroma , which is a benign tumor that grows on the connecting nerve between the ear and the brain
- Gliomas include ependymomas , which are tumors that grow on glial cells in the brain and spinal cord
- Meningioma , which is a tumor that grows in the meninges (protective membranes) in the brain and spinal cord
- Schwannoma, which is a tumor that appears on the protective covering of nerve fibers
Although symptoms and complaints are more common in their 20s, neurofibromatosis type 2 can also cause juvenile cortical cataracts , which are cataracts that appear in children.
Complaints that arise will depend on where the tumor grows. However, some of the symptoms or complaints that often indicate NF2 are:
- Ringing ears ( tinnitus )
- Balance disorders
- Hearing disorders
- Impaired vision and glaucoma
- Memory impairment
- Numbness in the face, arms, or legs
- seizures
- vertigo
- Difficult to swallow
- Articulation when speaking becomes less clear
- A lump appears under the skin
- Pain due to peripheral neuropathy
- back pain
When to see a doctor
Check with your doctor if you experience the symptoms mentioned above. Early detection and treatment are expected to prevent tumor development and complications due to type 2 neurofibromatosis.
Diagnosis of Type 2 Neurofibromatosis
The doctor will ask questions and answers about the patient's symptoms, medical history, and family history of type 2 neurofibromatosis. After that, the doctor will perform a nerve examination, ear examination, and eye examination. To confirm the diagnosis, the doctor will carry out supporting examinations in the form of:
- Scan with an MRI or CT scan , to detect a schwannoma, acoustic neuroma, meningioma, or glioma
- Genetic test , to find out whether there is a gene mutation
If you or your partner has type 2 neurofibromatosis, genetic testing can also be done from the time the child is in the womb. This aims to determine whether neurofibromatosis type 2 is passed on to the fetus.
Treatment of Type 2 Neurofibromatosis
Neurofibromatosis type 2 has no cure. However, there are treatments that can be done to relieve symptoms. The type of treatment will be adjusted to the complaints that arise.
Some of the treatment steps that will be carried out by the doctor are:
Observation
The doctor will make routine observations or observations. This is done to determine the development of tumors that grow when experiencing neurofibromatosis type 2. If complaints arise during observation, the doctor will carry out therapy according to the patient's condition.
During the observation, the doctor will perform an MRI scan to see the growth of the tumor, and periodically examine the eyes and ears.
Physiotherapy
The type of physiotherapy to treat neurofibromatosis type 2 will be adjusted to the complaints experienced by the patient. For example, patients with hearing loss will undergo therapy to train them how to communicate with others, one of which is by teaching sign language.
If the NF2 patient experiences ringing in the ears or tinnitus, tinnitus retraining therapy will be carried out . This therapy aims to train and help sufferers adapt to ringing in the ears.
Hearing aid fitting
Patients with neurofibromatosis type 2 often experience disturbances and even loss of hearing ability so that hearing aids or hearing implants are needed. There are two types of hearing implants that can be used, namely cochlear implants or auditory brainstem implants .
Operation
Surgery is performed to remove the tumor and prevent complications. Tumor removal is done if there is a large tumor and can damage the spinal cord or brain.
However, this procedure carries the risk of complications. Therefore, the doctor will consider the benefits and risks before carrying out this procedure.
Radiotherapy
Radiotherapy or radiation therapy is done with the help of X-ray energy to remove tumors. For tumors that are small and hard to reach, the doctor will perform a type of radiation therapy called gamma knife surgery .
However, the doctor will weigh the benefits and risks of radiotherapy in NF2. Because even though it is small, there is a risk of forming a new tumor that can develop into cancer.
Drugs
Medications to relieve nerve pain, such as gabapentin , topiramate , serotonin selective reuptake inhibitors (SSRIs), or amitriptyline , can be given by doctors if complaints of pain really bother the patient.
Type 2 neurofibromatosis complications
If not treated immediately, neurofibromatosis type 2 can cause complications in the form of:
- Permanent hearing loss or deafness
- Facial nerve damage
- Impaired vision
- Benign tumors on the skin
- Numb
Prevention of Type 2 Neurofibromatosis
Neurofibromatosis type 2 is a genetic disorder that is difficult or even impossible to prevent. However, genetic screening when planning a pregnancy can be done to determine the risk of passing genetic disorders to children.
If you have been diagnosed with type 2 neurofibromatosis, follow the recommendations and therapy given by your doctor. Also carry out controls according to the schedule given by the doctor so that your condition is always monitored.