Effect of nitrous oxide on spike activity during epilepsy surgery

There are controversies over the effect of nitrous oxide on the electrocorticograms in patients with epilepsy. To clarify the effect of nitrous oxide on electrocorticograms, spike activities were compared with and without nitrous oxide under neuroleptoanesthesia in 10 patients with intractable epilepsy during surgery. Spikes decreased with nitrous oxide significantly (P<0.01) and disappeared in 3 cases. We conclude that discontinuation of nitrous oxide should be taken into consideration during electrocorticographic monitoring in epilepsy surgery.