Progression of visual evoked potential abnormalities in multiple sclerosis and optic neuritis

To investigate visual signal processing in patients with optic neuritis, suspected multiple sclerosis, confirmed multiple sclerosis (MS), and optic neuritis combined with MS, pattern reversal visual evoked potentials (VEPs) were recorded in patients and normal subjects. The amplitude and latency of the first positive peak, P100 were determined to assess electrical conduction in patients as compared to normal subjects. Suspected MS patients did not differ from normal subjects in peak latencies or amplitudes. The P100 amplitude was reduced in optic neuritis, confirmed MS and optic neuritis combined with confirmed MS. The P100 and N145 latencies were prolonged in optic neuritis patients and confirmed MS patients as compared to normal subjects. The main characteristic of optic neuritis was P100 amplitude reduction, and of confirmed MS was P100 latency delay. There was a progression of the P100 latency delay and of the P100 amplitude decrement in optic neuritis, confirmed MS, and optic neuritis combined with confirmed MS. These results indicate a progression of demyelination in optic neuritis, confirmed MS, and optic neuritis combined with confirmed MS.