Click here to view next page of this article
Neurofibromatosis (NF) (von Recklinghausen disease) has a variety of manifestations, which may affect nearly every system and organ. Distinctive features may be present at birth but the development of complications is often delayed.
CLINICAL MANIFESTATIONS AND DIAGNOSIS. There are two distinct forms of neurofibromatosis. NF-1 is the most prevalent type of neurofibromatosis and is diagnosed if any two of the following signs are present: (1) At least five café-au-lait spots over 5 mm in greatest diameter in prepubertal patients or at least 3 mm in diameter. (3) Two or more iris Lisch nodules. Lisch nodules are hamartomas located within the iris and are best identified with a slit lamp examination. They are present in more than 90% of patients with NF-1 but are not a component of NF-2. (4) Two or more neurofibromas or one plexiform neurofibroma.
Children with NF-1 are susceptible to neurologic complications. Magnetic resonance imaging (MRI) studies in selected children have shown abnormal signals in the globus pallidus, thalamus, and internal capsule, which probably represent low-grade glioma or hamartoma that is not detected.
NF-2 accounts for 10% of all cases of neurofibromatosis and may be diagnosed when one of the following is present: (1) bilateral eighth nerve masses consistent with acoustic neuromas as demonstrated by CT scanning or MRI. (2) A parent, sibling, or child with NF-2 and either unilateral eighth nerve masses or any two of the following: neurofibroma, meningioma, glioma, schwannoma, or juvenile posterior subcapsular lenticular opacities. Bilateral acoustic neuromas are rare.
TREATMENT. As there is no specific treatment for neurofibromatosis, the management includes genetic counseling and early detection of treatable conditions or complications. The evaluation of a child with neurofibromatosis should include several baseline studies, such as an audiogram, auditory brain stem and visual evoked potentials, an electroencephalogram (EEG), psychologic testing (including studies predictive for learning disorders), a roentgenographic skeletal The majority of NF-2 cases are the result of a mutation. Examination of fetal DNA for the characteristic single-strand conformational polymorphism of an In familial cases, where affected and unaffected family members are available, linkage can be established, making prenatal diagnosis available.