Diagnosing Neurofibromatosis

Testing for Neurofibromastosis

Doctors often use MRI scans to diagnose neurofibromatosis. In addition, the Neuroradiology section of the Department of Pediatric Radiology, part of Children’s Hospital’s Brain Care Institute, offers the latest testing and diagnostic technologies, including:

• CT scan (computed tomography scans)
• Electroencephalogram (EEG)
• Tesla magnetic resonance imaging (MRI) scanners
• Electromyogram (EMG) and nerve conduction velocity
• Positron emission tomography (PET) scan
• Magnetic resonance angiogram (MRA) scan
• Cerebral spinal fluid analysis (spinal tap or lumbar puncture)
• Evoked potentials
• Myelogram
• Ultrasound (sonogram)
• Neurosonogram
• Magnetoencephalogram (MEG)
• MR spectroscopy
• Diffusion tensor imaging
• PET molecular imaging

Learn more about Child Neurology.

How is neurofibromatosis diagnosed?

To recieve a NF1 diagnosis, a person must have at least two of the symptoms that can be associated with this disease. These include:

• Family history of NF1 or confirmed mutation in the gene
• Spots on the skin, called café au lait spots, and freckling of the skin folds
• Tumors of the nerves in the skin
• Tumors of the nerves that of the eyes that bring visual information to the brain, or spots on the colored part of the eye (Lisch nodules)
• Unusual bony abnormalities (sphenoid wing dysplasia, tibial dysplasia)

Children with a NF2 diagnosis have fewer outward signs of the condition than individuals with NF1. This form of the disease often causes tumors on the nerves that connect the brain to both ears or on the brain itself, or particular kinds of cataracts in the eyes.

For NF2, to treat the acoustic neuromas, we consult with L. Dade Lunsford, MD, and gamma knife surgery at UPMC Presbyterian where we see children and adults (family-style) in the Neurofibromatosis Clinic.

What causes neurofibromatosis?

NF is caused by a change in genetic material. NF1 is caused by a change in a gene carried on chromosome 17. NF2 is caused by a change in a gene carried on chromosome 22. The changes in the genetic material that cause NF1 and NF2 can be inherited from a parent, which is referred to as autosomal dominant inheritance. NF also occurs spontaneously at conception about 50 percent of the time, meaning that there are no other affected family members. The NF gene is always present at birth, though symptoms may not appear until later in life.

Genetic Testing for Neurofibromatosis

Recently, direct gene testing has become available, meaning that a patient’s blood can be tested effectively without obtaining blood samples from other relatives. Direct gene testing, however, is not 100 percent accurate. Further research is necessary to make the testing for both neurofibromatosis types more accurate.