von Recklinghausen's Neurofib... Health Article

Diagnosis

Diagnosis of a form of neurofibromatosis is based on the symptoms outlined above. Although a visual inspection may be sufficient for inspection of tumors for a clinical diagnosis of neurofibromatosis, magnetic resonance imaging (MRI) may be useful for early diagnosis of tumors. Diagnosis of NF1 requires that at least two of the above listed symptoms are present. A slit lamp is used to visualize the presence of any Lisch nodules in a person's eye. A person with a parent, sibling, or child with NF1 is another tool used to diagnose a person with NF1.

NF2 can be diagnosed three different ways and with symptoms different from NF1 symptoms:

• The presence of bilateral cranial eighth nerve tumors.
• A person who has a parent, sibling, or child with NF2 and a unilateral eighth nerve tumor (vestibular schwannoma or acoustic neuroma).
• A person who has a parent, sibling, or child with NF2 and any two of the following: glioma, meningioma, neurofibroma, schwannoma, or an early age cataract.

The presence of multiple schwannomas may be a symptom of NF2 or schwannomatosis. An older person with multiple schwannomas and no hearing loss probably does not have NF2. A high-quality MRI scan should be used to detect any possible vestibular tumors to differentiate between NF2 and schwannomatosis in a younger person with multiple schwannomas or any person with hearing loss and multiple schwannomas.

In prepubertal children a yearly assessment including blood pressure measurement, eye examination, development screening, and neurologic examination is recommended.

Monitoring the progression of neurofibromatosis involves careful testing of vision and hearing (audiometry). X-ray studies of the bones are frequently done to watch 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 involvement of the acoustic nerve, and EEG (electroencephalogram, a record of electrical currents in the brain) may be needed for patients with suspected seizures.

Treatment

There are no cures for any form of neurofibromatosis. To some extent, the symptoms of NF1 and NF2 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, including gamma knife 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 types of tumors which an individual 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.

Clinical Trials

As of 2001, there were two clinical trials taking place involving people affected with NF (<http://clinicaltrials.gov>). Patients can contact the House Ear Institute for more information about the clinical trial, "Natural History of Vestibular Schwannomas in Neurofibromatosis 2." By the end of 2001, The House Ear Institute expected to expand the clinical trial to include people with whole body NF2. More information about the clinical trial "Diagnosis of Pheochromocytoma" can be obtained from the National Institute of Child Health and Human Development (NICHHD).

The use of an auditory brainstem implant (ABI) as part of hearing rehabilitation in patients with NF2 has been tested in Europe and the United States.