Halothane has anticonvulsant properties and can terminate status epilepticus. When used alone, halothane does not cause CNS irritability.36 In the few reports of halothane-related seizures, N2O was also administered.37

Rarely, sharp waves that are maximal over the vertex can appear during the first postoperative week, usually during the first 2 postoperative days. Persistence of an epileptogenic halothane metabolite (e.g., trifluoroacetic acid) may contribute to this sharp activity.36


Isoflurane, a commonly used inhalation agent, is an isomer of enflurane and contains little or no epileptogenicity.26 In the few cases of isoflurane-related seizures, N2O was also administered.38 Isoflurane has anticonvulsant properties; it suppresses drug-induced convulsions in animals39 and terminates status epilepticus in patients at inspired concentrations from 0.5% to 3.0%.40,41

Isoflurane reduces the frequency and field of spikes on the electrocorticogram of people with epilepsy.29,40


Desflurane is structurally similar to isoflurane. Compared to isoflurane, it has a more rapid onset of action and recovery.

The EEG patterns for desflurane are similar to those seen with equipotent doses of isoflurane. Burst suppression is easily achieved. There was some concern that EEG tolerance may develop to desflurane, but this has not been demonstrated in humans.42,43


Sevoflurane is an inhalation agent currently in use in Japan. Small studies have shown EEG but no clinical evidence of seizure activity with sevoflurane induction in patients with epilepsy. This effect was suppressed by giving nitrous oxide.44,54

Nitrous oxide

N2O has very low epileptogenic potential and has been used extensively in patients with and without epilepsy.23,45 N2O does not significantly affect neuronal firing in the human limbic areas.46

Among 11 epilepsy patients who underwent dental procedures, there were no EEG changes during anesthesia in 9 patients, and there was a decreased frequency of paroxysmal discharges in 2 patients.45

Adapted from: Najjar S, Devinsky O, Rosenberg AD, et al. Procedures in epilepsy patients. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;499–513. With permission from Elsevier (www.elsevier.com).

Authored By: 
Orrin Devinsky MD
Souhel Najjar MD
Andrew D Rosenberg MD
Reviewed By: 
Steven C. Schachter MD
Thursday, April 1, 2004