Neurofibromatosis
Neurofibromatosis is a genetic disorder that primarily affects the nervous system, skin, and bones, characterized by the development of multiple nerve tumors called neurofibromas, café-au-lait spots on the skin, and bone deformities. There are three main types: Neurofibromatosis type 1 (NF1), Neurofibromatosis type 2 (NF2), and Schwannomatosis, each varying in symptoms and severity. NF1, also known as Von Recklinghausen disease, often presents symptoms in early childhood, whereas NF2 and Schwannomatosis manifest later in life. Common symptoms include visible growths under the skin, chronic pain, and potential neurological complications such as hearing loss, balance issues, and weakness.
While there is currently no cure for neurofibromatosis, treatment focuses on supportive therapies, including surgical removal of tumors and reconstruction for disfigurement. Patients may also require counseling to cope with social challenges associated with the condition. Genetic factors play a crucial role in this disorder, which affects approximately one in every 3,000 births. Ongoing research aims to address the underlying genetic mutations, offering hope for future interventions.
Neurofibromatosis
ALSO KNOWN AS: Von Recklinghausen disease
ANATOMY OR SYSTEM AFFECTED: Bones, nervous system, skin
DEFINITION: A genetic disease affecting the nervous system, skin, and bones that produces multiple nerve tumors (neurofibromas), deeply pigmented areas of skin (café-au-lait spots), and bone deformities
CAUSES: Genetic factors
SYMPTOMS: Multiple nerve tumors, deeply pigmented areas of skin (café-au-lait spots), bone deformities
DURATION: Chronic
TREATMENTS: Supportive therapy, including surgical removal of neurofibromas, reconstructive plastic surgery to correct disfigurement, counseling
Causes and Symptoms
Neurofibromatosis can be classified into three categories: neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and Schwannomatosis, which vary in the type and location of the associated tumors. The latter two types are much rarer and involve Schwannoma tumors (schwannomas), which are tumors of the Schwann cells. They are all autosomal dominant genetic disorders caused by mutations of different genes, and may be hereditary or arise independently.
Most infants born with NF1, which is also known as Von Recklinghausen disease, and NF2 show symptoms by the age of ten, with some exhibiting signs from birth. Disease progression and signs and symptoms vary from mild (in about one-third of affected children) to moderate and severe disfigurement, neurological issues, and organ failure. The disease causes abnormal growths of nerve tissue along the peripheral nerve tracts of the head, neck, trunk, and extremities, usually involving the brain and spinal cord (the central nervous system) later. These so-called neurofibromas appear as multiple, visible growths lying beneath the skin. Also typical are the many areas of deeply pigmented skin, known as café-au-lait (coffee-and-milk) spots. In addition, severely disfiguring bone defects of the skull and spine can be caused by neurofibromas.
NF2 particularly exhibits vestibular schwannomas known as acoustic neuromas, which are slow-growing benign tumors on nerves in the ear. For this reason NF2 is marked by ringing in the ears, balance issues, headaches, and hearing loss. Schwannomas can also develop on nerves elsewhere in the body, such as the optic nerves, spinal nerves, and cranial nerves. Some of the problems these tumors can cause include pain, problems with vision, and weakness or numbness.
Schwannomatosis typically manifests in patients past the age of twenty. It consists of tumors of nerves in the skull, spine, and peripheral nervous system. Unlike NF2 it does not affect the nerve connecting the brain and the inner ear, so the hearing problems associated with NF2 are not present. It does cause chronic pain in various areas of the body as well as muscle loss, weakness, and numbness.
Some patients lead nearly normal lives, with only cosmetic problems from the café-au-lait spots and visible neurofibromas. Most patients, however, experience serious consequences from deep growths and skeletal deformities. Depending on the size and location of these tumors, they can cause blindness, deafness, developmental disorders, learning disabilities, seizures, pain, and paralysis. Other organs, especially the kidneys and glands, are frequently damaged as well. The most feared complication is the transformation of these benign tumors into cancerous ones.
Treatment and Therapy
No cure exists for neurofibromatosis. Supportive therapy includes surgical removal of the neurofibromas and reconstructive plastic surgery for the sometimes severe disfigurement that can result from deep tumors and bone deformities. The skull, spine, and eye sockets are particularly affected. Social isolation and embarrassment are serious problems with neurofibromatosis, and counseling is essential. The prognosis is variable depending on the size and location of the tumors. Both cancer and organ failure can shorten the patient’s life.
The acoustic neuromas of NF2 may be targeted with stereotactic radiosurgery (SRS), a process that does not make an incision. This can help avoid the hearing loss that might occur with other surgeries. Those with NF2 may also benefit from hearing implants, whether auditory brainstem or cochlear, in order to overcome hearing loss.
Schwannomatosis will typically require specialized pain management in addition to any required surgeries or other procedures. Some of the drugs used for nerve pain include Gabapentin (Neurotin) and pregabalin (Lyrica), while tricyclical antidepressants and Serotonin and norepinephrine reuptake inhibitors may also be prescribed. If tumors are causing seizures medications for epilepsy may be used.
Because neurofibromatosis is genetic, occurring in one in three thousand births, genetic analysis of the parents is essential if there is a family history of the disease. Prenatal testing can determine if the fetus has inherited the defect. Research is now focusing on correcting the genetic error in the developing fetus.
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