Seizure Elicitation Blocked by Pretreatment with Lidocaine

A patient is reported in whom pretreatment with intravenous lidocaine resulted in failure to elicit a seizure even at stimulus intensity markedly greater than that used successfully at prior and subsequent treatments. Together with one other report, this experience suggests that lidocaine may prevent a seizure by raising the seizure threshold. An alternative explanation is proposed for the classic findings of Ottosson that lidocaine-modified seizures are reduced in therapeutic efficacy.