Neurofibromatosis refers to three nervous system disorders that can cause tumors to develop, impacting the brain, spinal cord and nerves sending signals between the brain and other areas of the body. Most of the time, any tumors that develop because of neurofibromatosis are benign (non-cancerous), but some can be malignant (cancerous).
Gene mutations – whether spontaneous or inherited – play a role in the development of neurofibromatosis. In cases of neurofibromatosis, proteins that suppress growth in cells in the nervous system cannot function normally, resulting in increased cell growth, which can cause tumors to form.
Neurofibromatosis Diagnosis
Patients with possible neurofibromatosis can participate in genetic testing, especially when they do not have a family history of neurofibromatosis or do not have schwannomas (tumors made up of Schwann cells, the cells that make myelin that protects and covers the body’s peripheral nerves) on both sides of the body. An MRI is also key to diagnosing neurofibromatosis since it can provide detailed images of the spinal cord and brain and can show schwannomas on peripheral nerves.
Types of Neurofibromatosis
There are three types of neurofibromatosis: neurofibromatosis type 1, neurofibromatosis type 2 and schwannomatosis.
Neurofibromatosis Type 1
Neurofibromatosis type 1 (NF1) is the first type of neurofibromatosis and is also known as von Recklinghausen disease. This is the most common form of neurofibromatosis, and it can be inherited or result from a genetic mutation that occurs spontaneously. Children of parents with this type of neurofibromatosis have a 50 percent chance of inheriting the condition.
Most people with NF1 live normal lifespans, but they can experience different symptoms and issues throughout their lifetime. Patients may not be diagnosed until they are older, because more symptoms develop as they age.
NF1 has signs that doctors can look for:
- At least six light brown, flat spots on the skin
- A large neurofibroma (tumor) involving more than one nerve, or at least two soft, pea-sized tumors in the skin
- Freckles in the groin or armpits
- At least two tumors on the iris of an eye
- A tumor on the optic pathway
- Deformed bones
- Cardiovascular issues
- Seizures or headaches
- Scoliosis
Additionally, children with NF1 can experience the following:
- Larger than average head
- Shorter than average height
- Poor performance on academic tests
- Attention deficit hyperactivity disorder (ADHD) or social skill deficits
There is no cure for NF1, but there are multiple treatments available as needed for patients to manage symptoms of the condition. In some cases, patients may not need treatment for the condition, but all patients with NF1 need to be periodically examined by an NF1 specialist, even if they do not have symptoms.
Patients at least 2 years of age with NF1 can take selumetinib (Koselugo®), which is an FDA-approved medication that can prevent existing tumors from growing. Also, if there is a risk of a tumor becoming cancerous or if tumors are causing adverse symptoms, surgical removal of the tumors can be an option.
Other symptoms arising because of NF1, such as seizures and headaches, can be treated with medications. Also, it is important for children with NF1 to be referred to a specialist to have neuropsychological assessments to rule out or diagnose autism, ADHD, learning disabilities and other disorders. These assessments can be key in helping these children get individualized educational plans.
Neurofibromatosis Type 2
Neurofibromatosis type 2 (NF2) is a rarer type of neurofibromatosis than NF1. About half of the people with NF2 inherit it, and the other half have a spontaneous genetic mutation. Like NF1, children of parents with NF2 have a 50 percent chance of inheriting the condition.
Signs and symptoms can include:
- Slow-growing benign tumors that impact the peripheral, spinal and cranial nerves and the meninges (the covering of the spinal cord and brain)
- Schwannomas on the skin
- Vision problems
- Peripheral neuropathy, which causes weakness and numbness in the legs or arms
- Balance or hearing problems
- Seizures
NF2 tends to become evident at an early age. However, children’s symptoms can be overlooked, especially when they do not have any parents, siblings or other family members with NF2.
Patients with NF2 benefit the most from being seen at specialty clinics with follow-up exams at least annually. Surgery may be possible, depending on the size of the tumors and how much hearing loss the patient has experienced.
Schwannomatosis
Schwannomatosis (SWN) is the least common type of neurofibromatosis. Most of the cases occur because of gene mutations, but research is being conducted regarding whether SWN can be inherited.
SWN can have the same signs and symptoms as NF2, and some with SWN may have no symptoms. However, additional signs and symptoms can include:
- Chronic pain in any part of the body
- Loss of function, weakness, tingling or numbness in toes or fingers
About 33 percent of people with SWN have tumors in just one part of the body, such as on part of the spine, a leg or an arm.
SWN has no accepted treatment, but surgery may be an option for patients with tumors that are increasing in size, or for patients with symptoms that are resulting from individual schwannomas. Surgery for SWN patients can potentially cause nerve damage, though, so it is important for these patients to consider the pros and cons of surgery.
UofL Health’s Restorative Neuroscience – Neuro-oncology Program can provide medical and surgical treatment options for adults who have or may have neurofibromatosis. You can call 502-588-2160 to schedule an appointment.
