Neurofibromatosis: Causes, Symptoms, Diagnosis, Treatment

Neurofibromatosis is a genetic dysfunction in which there is disturbance of cell growth in the nervous system resulting in formation of tumors in the nerve tissue. The tumors may form anywhere in the nervous system to include the brain, spinal cord, or nerves. This condition is normally diagnosed in early childhood or adolescence. These tumors are usually benign, but in some instances these tumors become malignant. Individuals affected with Neurofibromatosis usually have only mild form of symptoms to include hearing loss, learning disability, or cardiac dysfunction. In some cases, as a result of compression of the nerves due to the tumor there may be significant impairment of vision or the affected individual can suffer from severe pain. The treatment for Neurofibromatosis is directed towards promoting a healthy growth and managing complications effectively.

Neurofibromatosis is caused by genetic mutations, which is either inherited or occur on its own during conception. The gene mutation involved decides which form of Neurofibromatosis the child will have. The following are the types of Neurofibromatosis:

Neurofibromatosis 1 (NF1): This type of Neurofibromatosis is caused due to mutations in gene NF-1 which is located in chromosome 17. This gene is responsible for producing a protein called neurofibromin whose function is regulating cell growth. Mutation of this gene results in neurofibromin loss, which affects cell growth in a controlled fashion.

Neurofibromatosis 2 (NF2): Same is the case with this type of Neurofibromatosis, except that the defect is in gene NF2, which is located in chromosome 22, the function of which is to produce a protein called Merlin which regulates cell growth and a defect in this gene causes abnormal cell growth.

The Symptoms Of Neurofibromatosis Depend On The Type Of The Disease.

Neurofibromatosis 1 (NF1): This type of Neurofibromatosis develops in childhood. Some of the symptoms of this type of Neurofibromatosis are flat brown spots on skin, also called as café au lait spots are quite common in people but in people with Neurofibromatosis type-I these are found in abundance. Apart from this, there will be freckling in armpits or groin, soft bumps on the skin, minute bumps on the iris of the eye along with severe bone deformities, learning problems, abnormally large head, and short stature.

Neurofibromatosis 2 (NF2): This type of Neurofibromatosis is much less common and some of the symptoms are development of acoustic neuroma in both ears causing the following symptoms:

• Progressive hearing loss
• Tinnitus
• Balance disorder.

In some instances, this type of Neurofibromatosis can cause development of schwannomas and cause the following symptoms:

• Facial drooping
• Numbness and weakness of the extremities
• Pain
• Balance disorder.

In order to diagnose Neurofibromatosis, the treating physician will take a detailed history along with an account of the symptoms experienced by the individual and the family history. The physician will then order certain tests depending on which type of Neurofibromatosis is suspected and will include:

Neurofibromatosis Type-I can be diagnosed by physical examination looking for abundant café au lait spots on the skin. If there is a family history of Neurofibromatosis then diagnosis becomes that much more easier. Apart from this, the physician will order:

• Ophthalmological Examination: A detailed ophthalmological examination can detect minute bumps on the iris and presence of cataracts which can confirm the diagnosis
• Audiological Examination: Tests like audiometry, ENG, and brainstem auditory evoked response tests can help determine hearing and balance level of an individual suspected with Neurofibromatosis type 2.
• Imaging Tests: Tests like X-rays, CT scan, and MRI are usually not done, but can be helpful in identifying bone abnormalities associated with Neurofibromatosis

There is no definitive cure for Neurofibromatosis and treatment is aimed at controlling symptoms and preventing complications that may arise from this disease. The treatment for Neurofibromatosis requires multidisciplinary approach and may involve the following:

In case of a child is diagnosed with Neurofibromatosis type I, then the physician may recommend close observation of the child with regular checkups commensurate with the age of the child and look for development of neurofibroma, look for signs of hypertension, assess the growth of the child, observe for any bony abnormalities, evaluate the intellectual abilities of the child. Regular eye checkups will also be conducted to look for any changes in the status of the eyes or development of any small bumps in the iris. As the child grows, the frequency at which the child is monitored can be designed to fit the individual’s needs.

Surgical Treatment For Neurofibromatosis: Surgery is recommended in case the tumors start compressing the adjacent tissues and nerves or are adversely affecting vital organs of the body. Surgery more often than not relieves all the symptoms that arise from Neurofibromatosis.

In case if an individual has decreased hearing due to Neurofibromatosis, then surgery may be required to remove the vestibular schwannomas causing it which may help the hearing capabilities of the individual. Apart from this, a surgical procedure called as stereotactic radiosurgery can also be done to preserve hearing of an individual.

Apart from surgery, brainstem and cochlear implants can be useful to preserve the hearing.