Relationship of high blood lactate levels with latency of visual-evoked potentials.

We studied, in healthy adult subjects, the association of high blood lactate levels, induced with an exhaustive exercise (12 subjects) or an intravenous infusion (four subjects) of a lactate solution (3 mg/kg in 1 min), with amplitude and latency of visual-evoked potentials. Amplitude of N75, P100, and N145 components did not show significant changes, whereas latency of P100 was reduced at exercise's end and that of N145 increased 10 min after the conclusion. Therefore, an increase of blood lactate induced by an exhaustive exercise or an intravenous infusion appears to induce an improvement in the conduction time between eye and striate cortex, while it seems to evoke a worsening of intracortical communication between striate and extrastriate areas.