Use of visually evoked responses in evaluation of visual blurring in brain-damaged patients

Pattern visual evoked potentials were recorded in brain-damaged patients who complained of fluctuation of vision causing visual blurring. Continuous prolonged pattern stimulation revealed marked variability of P100 amplitudes. In contrast, normal subjects and brain-damaged patients who did not complain of visual blurring showed stable P100 amplitudes. Fluctuation of vision thus seems to have an electrophysiological correlate in terms of P100 amplitude lability, which can be objectively assessed by prolonged continuous recording of pattern visual evoked potentials.