Neurofibromatosis – What and How, a Columbia University Medical Center Neurosurgeon’s Take

May. 17, 2018


Neurofibromatosis is a disease many people have never heard of. This tumor-causing disorder impacts people from a very young age, often from birth, and leads to problems such as pain, disfigurement and disability that last a lifetime. That’s why the Children’s Tumor Foundation has named May 17th Neurofibromatosis Awareness Day. Take a moment to learn about this disease, so you too can spread the word and help find a cure.

What is neurofibromatosis?
Neurofibromatosis, or NF for short, is a disorder that causes the growth of neurofibromas. These non-cancerous, or benign, tumors, called neurofibromas, grow from cells that surround and support nerves, so they can grow pretty much anywhere in the body. NF can cause symptoms that vary widely from person to person, but in general they have to do with the location of the tumor growth. According to Dr. Christopher Mandigo of the Spine Hospital at the Neurological Institute of New York, “Tumors can grow and cause compression. External compression of the nervous system can cause dysfunction.” Rarely, one of these benign tumors becomes cancerous and creates another set of issues for the patient.

There are three distinct types of NF, and each type has characteristics that distinguish it from the others.

Neurofibromatosis 1 (NF1) is the most common form of the disease, affecting one in every 3,000 people worldwide. The disease is characterized by flat, light brown spots that look like oversized freckles–commonly called café au lait spots. Often freckling occurs under the arms and in the groin in individuals with NF1. In addition, they develop neurofibromas just under the skin, causing noticeable skin nodules. Some people will have soft bones and scoliosis (a curved spine) as a result. A few will develop tumors in the brain or spinal cord, though those aren’t the most common sites for neurofibromas. Roughly half have learning disabilities. Most often, signs of the disease are present at birth, and almost all cases are diagnosed before the age of 10.

Of particular concern with NF1 is the development of tumors along the nerves where they exit the spinal cord. If these tumors compress the nerves, they cause pain, numbness and tingling, movement issues such as poor hand coordination or difficulty walking, and bowel and bladder problems.

Neurofibromatosis 2 (NF2) is less common than NF1, affecting roughly one in 25,000 people. This form of NF often affects the eighth cranial nerve, which carries sound and balance information between the brain and the ear. These particular tumors are called acoustic neuromas and typically affect the nerves on both sides of the brain, leaving the individual with hearing loss and balance issues. NF2 can also cause problems in the eyes, spine and brain. Individuals with NF2 are typically diagnosed in their late teens or early 20s, when hearing issues begin to develop. 

Schwannomatosis is the rarest form of NF, impacting one in 40,000 people, and can result in facial weakness, bowel and bladder problems, vision changes and headaches. In schwannomatosis, tumors exclusively form from Schwann cells. These cells function much like the plastic coating on electrical wire, insulating the nerve so the signal is not lost. Schwann cells are only present in the peripheral nervous system—meaning they affect nerves throughout the body, but not within the spinal cord or brain. Other cells, called oligodendrocytes, serve the same purpose in the central nervous system, but are not affected by schwannomatosis.

What causes neurofibromatosis?
Neurofibromatosis is a genetic disorder that is expressed in an autosomal dominant manner. This pattern is somewhat more complicated in schwannomatosis than in NF1 and NF2, but in general it means that if a person has the mutation she will have symptoms of the disease. It also means that an affected individual has a 50 percent chance of passing the disease to biological children.

If a child does not inherit the disorder from a parent, she does not have the gene for it and cannot pass it to subsequent generations of children.

Not all cases of NF are inherited from a parent. In roughly half of all cases, a new, random mutation causes NF. But once an individual has the mutation, she has the disease, and then has a 50 percent likelihood of passing it on.

How is neurofibromatosis treated?
There is no cure for NF. Instead, patients are treated according to the symptoms they develop. For some this means careful watching, while for others it may mean careful collaboration with a pain control specialist to manage nerve pain. Other patients may require surgery for tumors if they grow in a way that compresses surrounding structures and causes symptoms of pain or disability.

Dr. Mandigo explains that since there is no cure for NF, one of the most important aspects of surgical care of the NF patient is knowing when to intervene and when to watch and wait.  While Dr. Mandigo is an expert in treating neurofibromas related to the spine, Dr. Michael Sisti, neurosurgeon and Co-Director of Columbia University Medical Center’s Brain Tumor Center, is an expert in treating acoustic neuromas and schwannomatosis

We recently spoke to Dr. Mandigo about his approach to the treatment of neurofibromas, and you can listen to an excerpt from that conversation in this audio file:

What is the future for neurofibromatosis?
NF is the focus of much research. Because it is a genetic disorder, there is hope that gene therapy will one day provide a cure for the disease. In addition, a significant amount of research focuses on medications that can prevent or slow the growth of neurofibromas. And you can help too. Now that you know more about this disease, do your part and get the word out.

To learn more about neurofibromatosis, hear from individuals that have been affected by the disease and their hope for the future, you can view a video from the Children’s Tumor Foundation here.

If you would like to learn more about Dr. Mandigo, click here.
If you would like to learn more about Dr. Sisti, click here.

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