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The applications of time-frequency analyses to ictal magnetoencephalography in neocortical epilepsy
| Title: | The applications of time-frequency analyses to ictal magnetoencephalography in neocortical epilepsy |
| Authors: | Yagyu, Kazuyori Browse this author | | Takeuchi, Fumiya Browse this author | | Shiraishi, Hideaki Browse this author | | Nakane, Shingo Browse this author | | Sueda, Keitaro Browse this author | | Asahina, Naoko Browse this author | | Kohsaka, Shinobu Browse this author | | Umeoka, Shuichi Browse this author | | Usui, Naotaka Browse this author | | Baba, Koichi Browse this author | | Saitoh, Shinji Browse this author |
| Keywords: | Ictal onset | | Propagation | | Polyspike | | Short-time Fourier transform | | Ictal discharge | | Rhythmic activities |
| Issue Date: | Aug-2010 |
| Publisher: | Elsevier B.V. |
| Journal Title: | Epilepsy Research |
| Volume: | 90 |
| Issue: | 3 |
| Start Page: | 199 |
| End Page: | 206 |
| Publisher DOI: | 10.1016/j.eplepsyres.2010.05.001 |
| PMID: | 20605700 |
| Abstract: | Purpose: Ictal magenetoencephalographic (MEG) discharges convey significant information about ictal onset and propagation, but there is no established method for analyzing ictal MEG. This study sought to clarify the usefulness of time-frequency analyses using short-time Fourier transform (STFT) for ictal onset and propagation of ictal MEG activity in patients with neocortical epilepsy. Methods: Four ictal MEG discharges in two patients with perirolandic epilepsy and one with frontal lobe epilepsy (FLE) were evaluated by time-frequency analyses using STFT. Prominent oscillation bands were collected manually and the magnitudes of those specific bands were superimposed on individual 3D-magnetic resonance images. Results: STFT showed specific rhythmic activities from alpha to beta bands at the magnetological onset in all four ictal MEG records. Those activities were located at the vicinity of interictal spike sources, as estimated by the single dipole method (SDM), and two of the four ictal rhythmic activities promptly propagated to ipsilateral or bilateral cerebral cortices. The patients with FLE and perirolandic epilepsy underwent frontal lobectomy and resection of primary motor area, respectively including the origin of high-magnitude areas of a specific band indicated by STFT, and have been seizure free after the surgery. Conclusions: STFT for ictal MEG discharges readily demonstrated the ictal onset and propagation. These data were important for decisions on surgical procedure and extent of resection. Ictal MEG analyses using STFT could provide a powerful tool for noninvasive evaluation of ictal onset zone. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/43835 |
| Appears in Collections: | 医学院・医学研究院 (Graduate School of Medicine / Faculty of Medicine) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 柳生 一自
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