Follow-up studies of visual potentials in multiple sclerosis evoked by checkerboard and foveal stimulation.

Visual cortical potentials were evoked by reversal of a checkerboard pattern and a small quadrangular foveal stimulus. Examination of 68 patients with MS showed the highest detection rate for abnormality of VEPs with a combination of both methods. Follow-up studies revealed changes (improvement or impairment) of VEP amplitudes or latencies in nearly half of the patients. Most of the changes were correlated with a history of acute optic neuritis. For the detection of changes the foveal stimulus is preferable to the checkerboard pattern.