Magnetoencephalography source localization and surgical outcome in temporal lobe epilepsy.
OBJECTIVE
We prospectively investigated the role of magnetoencephalography (MEG) in localizing the seizure focus and in predicting outcome to surgical resections for intractable temporal lobe epilepsy (TLE).


METHODS
We performed simultaneous interictal EEG and MEG recording (two 37-channel system) in 26 TLE patients followed by MEG source localization. We correlated early modeling dipoles with intracranial EEG, temporal surgical resection and surgical outcome.


RESULTS
There were 12 patients who had anterior temporal horizontal or tangential dipoles to the anterior infero-lateral temporal tip cortex. Two patients underwent selective amygdalo-hippocampectomy (SAH) and nine patients had antero-medial temporal lobectomy (AMTL). All patients had successful outcome except for one patient who initially failed SAH, but became seizure-free after AMTL. There were 11 patients who demonstrated anterior temporal vertical or tangential oblique dipoles. Five patients had AMTL and three had SAH; all became seizure free. Five of above 23 patients had invasive EEG and demonstrated mesial seizure onset. Three TLE patients had lateral vertical dipoles that were concordant with intracranial EEG and these became seizure free after temporal neocortical resections.


CONCLUSIONS
MEG source analysis produces distinct source patterns that provide useful localizing information, predict surgical outcome, and may aid in planning limited surgical resection in TLE.
Assaf
Bassam A
BA
Department of Neurology, The University of Illinois-Peoria, 530 N. Glen Oak Ave., Peoria, IL 61637, USA. bassam.a.assaf@osfhealthcare.org
Karkar
Kameel M
KM
Laxer
Kenneth D
KD
Garcia
Paul A
PA
Austin
Everett J
EJ
Barbaro
Nicholas M
NM
Aminoff
Michael J
MJ
D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D013702:Temporal Lobe / Q000503:physiopathology; D016896:Treatment Outcome