The role of visual evoked potentials in the differential diagnosis of functional visual loss and optic neuritis in children.

This study aims to determine whether visual evoked potentials can aid the diagnosis of functional visual loss and differentiate it from optic neuritis in children. The medical records and visual evoked potentials of 72 patients registered in the neurophysiological database of our Institution in the period 2000-2009, with diagnoses of functional visual loss or optic neuritis were reviewed retrospectively. In 61 children, visual evoked potentials confirmed the diagnosis: 49 functional visual loss and 12 optic neuritis. Visual evoked potentials were normal in all patients but 1 in the functional visual loss group, while all were abnormal in the optic neuritis group. Overlapping clinical features occurred between the 2 groups as well as prevalent severe visual loss, relative afferent pupillary defect, and papillitis in optic neuritis. Visual evoked potentials are of value in confirming clinical suspicion of functional visual loss, particularly when clinical overlap with optic neuritis occurs.