Neurofibromatosis Health Article

Diagnosis

Diagnosis is based on the broad spectrum of clinical signs previously described, which usually can be detected by careful physical examination, ophthalmologic evaluation (visualizing the structures in the eye) and audiogram (test to measure hearing ability). Diagnosis of NF-1 requires that at least two of the listed signs are present. Diagnosis of NF-2 requires the presence of either a mass on the acoustic nerve or another distinctive nervous system tumor. An important diagnostic clue for either NF-1 or NF-2 is the presence of the disorder in a patient's parent, child, or sibling. A test to detect a protein (the end-products of a gene) relevant to NF-1 mutagenesis has been created, but accuracy for this procedure has not been established.

Monitoring the progression of neurofibromatosis involves careful testing of vision and hearing. X ray studies of the bones are frequently indicated to detect for the development of deformities. CT scans and MRI scans are performed to track the development/progression of tumors in the brain and along the nerves. Auditory evoked potentials (the electric response evoked in the cerebral cortex by stimulation of the acoustic nerve) may be helpful to determine acoustic nerve involvement, and EEG (electroencephalogram, a record of electrical impulses in the brain) may be required for patients with suspected seizures. Regular blood pressure monitoring is also advised.

Treatment

There are no available treatments for the disorders which underlie either type of neurofibromatosis. To some extent, the symptoms of NF-1 and NF-2 can be treated individually. Skin tumors can be surgically removed. Some brain tumors, and tumors along the nerves, can be surgically removed, or treated with drugs (chemotherapy) or x-ray treatments (radiation therapy). Twisting or curving of the spine and bowed legs may require surgical treatment, or the wearing of a special brace.

Prognosis

Prognosis varies depending on the tumor type which develops. As tumors grow, they begin to destroy surrounding nerves and structures. Ultimately, this destruction can result in blindness, deafness, increasingly poor balance, and increasing difficulty with the coordination necessary for walking. Deformities of the bones and spine can also interfere with walking and movement. When cancers develop, prognosis worsens according to the specific type of cancer.

Prevention

There is no known way to prevent the approximately 50% of all NF cases that occur due to a spontaneous change in the genes (mutation). New cases of inherited NF can be prevented with careful genetic counseling. A person with NF can be made to understand that each of his or her offspring has a 50% chance of also having NF when a parent has NF. Special tests can be performed on the fetus (developing baby) during pregnancy to determine if the fetus will be born with this disorder. Amniocentesis (where a needle is passed through the mother's abdomen into the amniotic sac which contains the amniotic fluid and cushions the developing fetus) or chorionic villus sampling (a procedure involving extraction of a tissue sample from the placenta, the structure which connects the fetal blood with the mother, necessary for nutrient and waste exchange) are two techniques which allow small amounts of fetal DNA (deoxyribonucleic acid, the chemical which contains specific codes which determine genetic makeup of an individual) removed for analysis. The tissue can then be examined for the presence of the parent's genetic defect. Some families choose to use this information in order to prepare for the arrival of a child with a serious medical condition. Other families may choose not to continue the pregnancy.

BOOKS

Haslam, Robert H. A. "Neurocutaneous Syndromes." In Nelson Textbook of Pediatrics, edited by Richard Behrman. Philadelphia: W. B. Saunders Co., 1996.

PERIODICALS

"Health Supervision for Children with Neurofibromatosis." Pediatrics 96, 2 (August 1995): 368+.

Heim R. A., et al. "Distribution of 13 truncating mutations in the neurofibromatosis 1 gene." Human Molecular Genetics 4 (1995): 975-81.

Levy, Charles E. "Physiatry and Care of Patients with Neurofibromatosis." The Journal of the American Medical Association 278, 18 (November 12, 1997): 1493+.

Waller, Amy L., and James E. Baumgartner. "Current Concepts in the Management of Neurofibromatosis Type 1." Physician Assistant 21, 8 (August 1997): 103+.

ORGANIZATIONS

March of Dimes Birth Defects Foundation. National Office, 1275 Mamaroneck Ave., White Plains, NY 10605. (888) 663-4637. resourcecenter@modimes.org. <http://222.modimes.org>.

The National Neurofibromatosis Foundation, Inc. 95 Pine St., 16th Floor, New York, NY 10005. (800)323-7938. <http://nf.org>.

Neurofibromatosis, Inc. 8855 Annapolis Rd., #110, Lanham, MD 20706-2924. (800) 942-6825.

Laith Farid Gulli, MD