MULTIMODAL ESTIMATION OF EPILEPTIC FOCI WITH DIPOLE LOCALIZATION METHOD AND OTHER TECHNIQUE

To clarify the diagnostic value of the dipole localization method in e stimating the epileptic focus in various types of localization-related epilepsy, dipole analysis of interictal spikes in epileptic patients was performed. Three-layered realistically-shaped models (Scalp-Skull- Brain model, SSB model) were used to compare the results with regional abnormalities revealed by various neuroimaging techniques and clinica l manifestations. Subjects were 22 patients with localization-related epilepsy, including 11 cases with localized MRI abnormalities and 9 ca ses with abnormal SFECT findings. The results of spike dipole location coincided with the clinical findings in 20 of 22 cases. In the two ca ses with frontal lobe epilepsy, the results did not coincide. In 10 of 11 cases with MRI abnormality dipoles were located within the area of organic lesions. In all 10 cases with SPECT abnormal findings, region al hypoperfusion was found at the area corresponding to the location o f the dipole, although SPECT findings showed a wider area as the epile ptic focus. In conclusion, dipole estimation using the SSB model can b e considered to be a useful technique for noninvasive investigation of epileptic focus.