Comparison of Cheek Electrode with Sphenoidal Electrodes for Identification of Ictal Onset Activity

Cho, Yong Won

Abstract

BACKGROUND: The sphenoidal electrodes are used to localize epileptiform discharge in temporal lobe epilepsy. However, the insertion of the sphenoidal electrodes is a semi-invasive procedure that is painful and uncomfortable. The sensitivity of sphenoidal electrodes varies depending on the tip position of the wire electrode. We investigated the usefulness of cheek electrodes for the identification of the ictal onset activity in temporal lobe epilepsy, and then compared it with that of sphenoidal electrodes.
METHODS
Both the cheek electrodes and the sphenoidal electrodes were positioned and seizure monitoring was performed on 17 patients suffering from complex partial seizures. Remontaging the EEG using the sphenoidal and cheek electrodes produced EEG printouts for each seizure, alternatively. Two neurologists interpreted all of the records independently. The EEGs were used to lateralize and localize the ictal onset activity and time of onset of ictal activity.
RESULTS
There were a total of 95 seizures in the 17 patients. The overall amplitude recorded by cheek electrodes was slightly lower than sphenoidal electrodes. But there were no significant differences between these two types of electrodes in detection of ictal onset.
CONCLUSIONS
The cheek electrodes are comparable with the sphenoidal electrodes in its effectiveness for the localization of ictal activity in patients with complex partial seizures. It is a relatively comfortable technique. It may replace sphenoidal electrodes for the identification of ictal onset activity in complex partial seizures.