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Combined use of sphenoidal electrodes and the dipole localization method for the identification of the mesial temporal focus
Author(s) -
Yoshinaga H.,
Hattori J.,
Nakahori T.,
Ohtsuka Y.,
Oka E.,
Tomita S.,
Ohmoto T.,
Miyamoto K.
Publication year - 2001
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1046/j.1468-1331.2001.00202.x
Subject(s) - temporal lobe , ictal , mesial temporal lobe epilepsy , epilepsy , frontal lobe , electroencephalography , dipole , medicine , epilepsy surgery , lobe , neuroscience , anatomy , psychology , physics , quantum mechanics
We attempted to sub‐classify four cases who show temporal spikes on standard scalp electroencephalogram (EEG), using sphenoidal electrodes and the dipole localization method. In a case with mesial temporal epilepsy, spikes showed phase reversal in a sphenoidal electrode, and the spike dipoles were estimated to be in the mesial temporal lobe. In a case with lateral temporal epilepsy, spikes showed no phase reversal in a sphenoidal electrode, and the spike dipoles were estimated to be in the lateral temporal lobe. In two cases out of four, spikes showed phase reversal in sphenoidal electrodes, whilst the dipoles were estimated to be in the frontal lobe. Clinical features also suggested a diagnosis of frontal lobe epilepsy. In one of the two cases in which frontal lobe epilepsy was suspected, ictal dipoles as well as interictal spike dipoles indicated participation of the frontal lobe in the genesis of seizures. Nevertheless, only mesial temporal lobectomy was performed based on results obtained by invasive subdural electrodes. As a result, seizures were not controlled. Although sphenoidal electrodes were useful for differentiating between mesial and lateral temporal lobe foci, it is advisable to use them in combination with the dipole localization method to identify frontal lobe foci.