Distribution of temporal spikes in relation to the sphenoidal electrode.
Sphenoidal EEG recordings were performed in 111 patients with epilepsy, who showed antero-mesial temporal epileptiform discharges. In 6, a multipolar sphenoidal electrode showed a shallow potential gradient between the standard sphenoidal site and the surface. In 17 patients a superficial electrode at the site of entry of the sphenoidal wire recorded all discharges seen at the sphenoidal. Out of 165 foci, in only 2 instances were less than 90% of sphenoidal discharges recognisable on the surface. In 39 patients who underwent surgery, lesions confined to mesial temporal structures were found to be associated with inter-ictal discharges maximal at the sphenoidal electrode. A mid-temporal maximum was always associated with diffuse non-specific, or lateral temporal pathology. It is concluded that sphenoidal recording offers no advantage over suitably placed scalp contacts for detecting inter-ictal epileptiform discharges. It may be of some value for differentiating between mesial and lateral temporal foci.
Binnie
C D
CD
Maudsley Hospital, Denmark Hill, London, U.K.
Marston
D
D
Polkey
C E
CE
Amin
D
D
D004566:Electrodes; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology*; D006801:Humans; D013101:Sphenoid Sinus; D013702:Temporal Lobe / Q000503:physiopathology*