The value of visual evoked potential as a screening test in neurofibromatosis.

Pattern reversal visual evoked potential (VEP) test was performed in 30 asymptomatic patients with neurofibromatosis (NF). All patients had normal visual acuity, visual fields, and ophthalmoscopic examination results. Pattern reversal VEP was abnormal in eight patients (26%). Seven of these patients had computed tomographic scans with reformated orbital views. Orbital computed tomographic scans were abnormal in six patients and in each case showed enlargement of the optic nerve on the side of VEP abnormality. Our data indicate that pattern reversal VEP is a valuable screening test in asymptomatic patients with NF. Because of the high incidence of VEP abnormality in such patients, VEP abnormality must be interpreted cautiously when a patient with NF is suspected of having other diseases or disorders that potentially affect the visual pathways.