Characteristics of MEG findings in patients with dysembryoplastic neuroepithelial tumor and ganglioglioma
Abstract number :
2.117
Submission category :
3. Neurophysiology / 3D. MEG
Year :
2017
Submission ID :
349659
Source :
www.aesnet.org
Presentation date :
12/3/2017 3:07:12 PM
Published date :
Nov 20, 2017, 11:02 AM
Authors :
Yutaro Takayama, Tohoku University Graduate School of Medicine; Kazutaka Jin, Tohoku University Graduate School of Medicine; Yosuke Kakisaka, Tohoku University Graduate School of Medicine; Akitake Kanno, Tohoku University Graduate School of Medicine; Mako
Rationale: Dysembryoplastic neuroepithelial tumor (DNT) and ganglioglioma are well-known tumors which frequently cause epilepsy. Surgical treatment is indicated for patients with DNT and ganglioglioma associated with drug-resistant epilepsy. Magnetoencephalography (MEG) is useful for presurgical evaluation of those patients, but the characteristics of the MEG findings have not been clarified. Methods: The present study included 5 epilepsy patients with DNT (3 men, aged 23-37 years) and 4 epilepsy patients with ganglioglioma (2 men, aged 21-44 years) who underwent simultaneous EEG/MEG recording in our institute from 2012 to 2017. Two of the 5 patients with DNT had a tumor in the temporal lobe, two in the frontal lobe, and one in the parietal lobe. All 4 patients with ganglioglioma had a tumor in the temporal lobe. MEG studies used a 200-channel axial gradiometer system (MEG vision PQA160C, Ricoh Company, Ltd., Tokyo, Japan). EEG was simultaneously recorded using 42-channel electrodes, with the modified 10-10 system. All patients underwent 3 T magnetic resonance (MR) imaging. EEG/MEG and MR imaging findings of these 9 patients were retrospectively reviewed. Results: MEG unique spikes not shown by EEG were detected in 3 of the 5 patients with DNT, but in only one of the 4 patients with ganglioglioma. All equivalent current dipoles of these MEG unique spikes had estimated perilesional locations, mostly oriented tangential to the convexity. Tumors in the 3 DNT patients with MEG unique spikes included a relatively large cystic component and were located at the convexity. The tumor in the ganglioglioma patient with MEG unique spikes did not have a large cystic component, and was located at the temporal base. Conclusions: In focal epilepsy associated with DNT, interictal spikes may be difficult to detect by EEG, but are easy to detect by MEG. The present results suggest that the occurrence of MEG unique spikes is associated with “relatively large cystic component” and “location at the convexity” in epilepsy patients with brain tumors. Funding: None
Neurophysiology