Magnetoencephalography in fronto-parietal opercular epilepsy.
OBJECTIVE
To clarify the clinical and neurophysiological profiles of fronto-parietal opercular epilepsy in which epileptic spikes are detected with magnetoencephalography (MEG) but not with scalp electroencephalography (EEG).


METHODS
Four patients presented with epileptic spikes localized to the fronto-parietal opercular cortex, which were only appreciated following MEG recordings.


RESULTS
In all cases, seizure semiology suggested early activation of the operculum and lower peri-rolandic cortex consistent with the somatotopic organization of this region, i.e. tingling sensation involving the throat and hemi-face or contralateral upper limb, and spasms of the neck and throat. MEG spikes were localized in the fronto-parietal operculum. Three of the four patients underwent invasive electrocorticography and/or stereo-EEG recordings, and spikes were confirmed to arise from the estimated area of MEG dipole localization. Two patients remained seizure-free for over 1 year after resection of the epileptogenic region; the other patient declined resective surgery due to proximity to the language cortex.


CONCLUSIONS
This study demonstrates the usefulness of MEG in localizing spikes arising from within the fronto-parietal opercular regions, and implies that MEG may provide localizing information in patients with symptoms suggestive of opercular epilepsy, even if scalp EEG recordings fail to disclose any epileptogenic activities.
Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA. kakisuke@mui.biglobe.ne.jp
Yosuke
Y
Kakisaka
Masaki
M
Iwasaki
Andreas V
AV
Alexopoulos
Rei
R
Enatsu
Kazutaka
K
Jin
Zhong I
ZI
Wang
John C
JC
Mosher
Anne-Sophie
AS
Dubarry
Dileep R
DR
Nair
Richard C
RC
Burgess
D000328:Adult; D004569:Electroencephalography / Q000379:methods / Q000592:standards; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods / Q000592:standards*; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000503:physiopathology*; D015203:Reproducibility of Results; D055815:Young Adult