Choose the topic you want to read.

• What is Neurofibromatosis?
• What are the symptoms of neurofibromatosis?
• What are the causes of neurofibromatosis?
• What are the risk factors of neurofibromatosis?
• What are the potential complications of neurofibromatosis?
• How is neurofibromatosis diagnosed?
• What are treatment modalities for neurofibromatosis?
• How can neurofibromatosis be prevented?
• A note from MedPark's doctor

Neurofibromatosis

Neurofibromatosis refers to a group of genetic disorders causing tumors of the nerves under the skin over the entire body. Tumors in neurofibromatosis are usually benign; however, they can become malignant. Common symptoms of neurofibromatosis include hearing loss, cardiovascular problems, learning impairment in children, vision loss, and problems balancing or controlling facial muscles.

Neurofibromatoses encompass three types:

• Neurofibromatosis 1 (NF1)
• Neurofibromatosis 2 (NF2)
• Schwannomatosis

What are the symptoms of neurofibromatosis?

Neurofibromatosis 1 (NF1)

Symptoms of NF1 are mild to moderate, often first noticeable at birth to age 10. They include:

• Neurofibromas: These are benign growths of the nerves under the skin. They increase in number with age and can be painful or symptomatic.
• Café au lait spots: Although they are common and harmless skin spots, six or more café au lait spots may indicate NF1. 
• Freckles: Freckles, smaller than café au lait spots, may appear in the armpits or groin area.
• Lisch nodules: These are small bumps on the iris of the eye. They are harmless and have no impact on the vision.
• Bone deformities
• Shorter height: Children affected by NF1 usually are shorter than average.
• Learning disabilities: These are common in children with NF1. ADHD, along with reading and writing difficulties, can also be present.
• Optic gliomas: 30% of individuals with NF1, especially children, develop optic glioma.

Neurofibromatosis 2 (NF2)

This condition is less common than NF1, usually diagnosed in early adulthood. Symptoms of NF2 are due to benign tumors of the ears (known as vestibular schwannomas or acoustic neuromas). Moreover, NF2 predisposes to the development of schwannomas in cranial, spinal, peripheral, and optic nerves. Symptoms of NF2 include:

• Schwannomas
• Hearing loss
• Balance problems
• Dizziness
• Tinnitus
• Cataracts
• Peripheral neuropathy

Schwannomatosis

This condition is a rare type of neurofibromatosis, usually affecting individuals 20 years old and over. Tumors of schwannomatosis develop on peripheral, cranial, and spinal nerves. Unlike NF2, schwannomatosis does not affect auditory nerves, hence no hearing loss. Schwannomatosis symptoms can vary depending on where tumors develop. They include:

• Schwannomas
• Chronic pain
• Loss of muscle
• Numbness and weakness
• Vision changes
• Headaches
• Bowel dysfunction and urination difficulty

What are the causes of neurofibromatosis?

Mutations affecting specific genes result in different types of neurofibromatosis. Neurofibromatosis 1 is secondary to a mutation of the neurofibromin 1 gene on chromosome 17, while neurofibromatosis 2 is due to a mutation in the neurofibromin 2 gene on chromosome 22. Schwannomatosis is due to the mutations of two genes: SMARCB1 and LZTR1.

What are the risk factors of neurofibromatosis?

Since neurofibromatosis is due to specific gene mutations, positive family history is the principal risk factor. For NF1 and NF2, the likelihood of inheriting the disease from an affected parent is about 50%. As for schwannomatosis, the risk of inheriting the condition from an affected parent is 15%.

What are the potential complications of neurofibromatosis?

In addition to the symptoms, complications can arise from the tumors affecting the nerves or internal organs. Various types of neurofibromatosis come with different complications. For example:

NF1 complications

• Concern over appearance: Patients with multiple cafe au lait spots or neurofibromas may develop emotional stress 
• Osteoporosis and scoliosis: Since NF1 can lead to abnormal bone development and is associated with decreased bone mineral density, osteoporosis and scoliosis can develop.
• Cardiovascular problems: Increased risk of hypertension and cardiovascular abnormalities.
• Cancer: Individuals with NF1 have a 3 - 5 percent likelihood of developing cancerous tumors. Plus, they also are more likely to have other forms of cancer.
• Neurological problems: A common neurological problem includes thinking difficulties.

NF2 complications

• Multiple meningiomas
• Facial nerve damage
• Vision problems

Schwannomatosis

• Severe pain

How is neurofibromatosis diagnosed?

Diagnosis for neurofibromatosis may start with a review of a patient's personal and family medical history, followed by a physical examination. For NF1, a doctor may check for cafe au lait spots.

To make the NF1 diagnosis, at least two signs or symptoms of the condition must be present. If only one sign is present without a family history, especially in a child, doctors will follow the patient for future development of additional signs and symptoms. For children, annual follow-up is advisable. A doctor may look for neurofibromas and high blood pressure, evaluate skeletal abnormalities, and assess their learning difficulties in school.

Additional suggested tests to aid the diagnosis include:

• Genetic tests: Tests to detect NF1 and NF2 can be done in pregnancy to determine if a fetus is affected by the diseases. Other genetic testing includes analysis for SMARCB1 and LZTR1 gene mutation, typically done prenatally.
• Imaging tests: MRIs, CT scans, and X-rays are beneficial in detecting tumors. These tests are more common for NF2 and schwannomatosis.
• Eye examination: This is to detect vision loss or Lisch nodules.
• Hearing and balance tests: Tests used to evaluate hearing and balance in NF2 patients include audiometry, electronystagmography, and brainstem auditory evoked response.

What are treatment modalities for neurofibromatosis?

There is no cure for neurofibromatosis; however, the symptoms can be managed through various treatment options. Treatments for neurofibromatosis include:

• Medication: Selumetinib is effective for plexiform neurofibroma (a variant of neurofibroma) in children. Pain medications, such as gabapentin, tricyclic antidepressants, topiramate, and amitriptyline can help manage pain caused by schwannomatosis.
• Surgery: Surgical intervention can remove part or all tumors causing symptoms. In instances of schwannomatosis, surgical removal can significantly reduce pain.
• Auditory brainstem and cochlear implants: Both devices help improve hearing for patients with NF2.
• Stereotactic radiosurgery: This procedure is suitable for NF2. In this procedure, radiation is delivered to shrink a tumor, mainly an acoustic neuroma. 

How can neurofibromatosis be prevented?

Although there is no known prevention for neurofibromatosis, genetic counseling can help individuals understand the likelihood of being pregnant with a child affected by the genetic condition.

How should you prepare for your appointment?

Before your appointment, you may prepare a list of your medical and family history, the medications, supplements, or vitamins you are taking, and questions to ask the doctor regarding available treatments or monitoring of the condition.

A note from MedPark's doctor

Neurofibromatosis, especially the most common type like NF1, can affect several body areas, including the nervous system and the skin. A medical specialist can suggest a suitable treatment for you. Plus, genetic counseling can be beneficial for reproductive planning, especially if there are concerns about the hereditary transmission of this condition.