title: The necessity for sphenoidal electrodes in the presurgical evaluation of temporal lobe epilepsy: pro position.
abstract: Whether sphenoidal electrodes should be used in the presurgical evaluation of people with refractory epilepsy has remained controversial. Many studies have been published touting their advantages, or conversely, their lack of benefit. The present paper reviews the evidence supporting the utility of sphenoidal electrodes. In principle, sphenoidal electrodes have an advantage over laterally placed scalp electrodes in detecting inferiorly directed mesial temporal discharges. Published studies demonstrate that sphenoidal electrodes are more sensitive than scalp electrodes and sometimes detect interictal spikes and seizures not seen with scalp electrodes. While the net added yield is relatively low, perhaps 5 to 10%, those patients in whom sphenoidal electrodes provide unique localizing information have much to gain. Sphenoidal electrodes may spare some patients unnecessary intracranial electrode investigation and permit surgery for others.
authors.affiliation: Department of Neurology, Jefferson Medical Callege, and Jefferson Comprehensive Epilepsy Center, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania 19107, USA. michael.sperling@jefferson.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sperling
authors.forename: Lia
authors.initials: L
authors.lastname: Guina
mesh_terms: D016477:Artifacts; D001931:Brain Mapping; D003937:Diagnosis, Differential; D004566:Electrodes / Q000009:adverse effects / Q000191:economics / Q000266:history; D004569:Electroencephalography / Q000379:methods; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000601:surgery; D049673:History, 20th Century; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009493:Neurosurgery; D012680:Sensitivity and Specificity