Distribution of temporal spikes in relation to the sphenoidal electrode

Electroencephalogr Clin Neurophysiol. 1989 Nov;73(5):403-9. doi: 10.1016/0013-4694(89)90089-8.

Abstract

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.

MeSH terms

  • Electrodes*
  • Electroencephalography*
  • Epilepsy / physiopathology*
  • Humans
  • Sphenoid Sinus*
  • Temporal Lobe / physiopathology*