Visual evoked cortical potentials (V.E.C.P.) by television presentation of different patterned stimuli to patients...

Visual pattern reversal evoked potentials constitute a test that can reveal early pathological changes in multiple sclerosis. Sixty nine subjects (52 controls, and 17 patients) were studied with this technique. The transient potentials evoked by checkerboard pattern reversal reveal an increase in the CII peak latency (significantly different from the controls) in M.S., with single elements of 15 and 30 min of arc and 20%-50% of contrast depth. The steady state potentials are absent or show phase lags in some patients with transient responses within the normal limits. The delayed evoked responses are detectable in a high percentage of patients with M.S., even when ocular symptoms are not seen in the clinical observation. Transient and steady-state E.Ps can furnish early tools for evaluation of functionality of visual pathways related to retinal form- and movement-analyzers, the former being sensitive to high spatial frequencies but conducting more slowly than the latter.