This greatly reduces the amount of EEG that needs to be reviewed. Detection is based on quantitative parameters such as wave frequency, amplitude, sharpness, rhythmicity, and duration. Sphenoidal electrodes may be used for temporal lobe epilepsy cases. These electrodes are thin, Teflon-coated, multistrand, stainless steel wires. Pain during the first day after the procedure is common, especially when chewing.
Rare complications are a transient facial palsy, infection, or wire breakage.
The wires are sterilized. The distant 3-5 mm of Teflon is removed. The region anterior to the ears is cleaned with antiseptic. Lidocaine is injected along the path where the electrodes are placed. The electrode is placed just below the inferior margin of the zygomatic arch and between the coronoid and condylar processes of the mandible, about 4 cm deep and about 2.5 cm anterior to the tragi of both ears.