OBJECTIVE: To evaluate the sensitivity of a simultaneous whole-head 306-channel magnetoencephalography (MEG)/70-electrode EEG recording to detect interictal epileptiform activity (IED) in a prospective, consecutive cohort of patients with medically refractory epilepsy that were considered candidates for epilepsy surgery. METHODS: Seventy patients were prospectively evaluated by simultaneously recorded MEG/EEG. All patients were surgical candidates or were considered for invasive EEG monitoring and had undergone an extensive presurgical evaluation at a tertiary epilepsy center. MEG and EEG raw traces were analysed individually by two independent reviewers. RESULTS: MEG data could not be evaluated due to excessive magnetic artefacts in three patients (4%). In the remaining 67 patients, the overall sensitivity to detect IED was 72% (48/67 patients) for MEG and 61% for EEG (41/67 patients) analysing the raw data. In 13% (9/67 patients), MEG-only IED were recorded, whereas in 3% (2/67 patients) EEG-only IED were recorded. The combined sensitivity was 75% (50/67 patients). CONCLUSION: Three hundred and six-channel MEG has a similarly high sensitivity to record IED as EEG and appears to be complementary. In one-third of the EEG-negative patients, MEG can be expected to record IED, especially in the case of lateral neocortical epilepsy and/or cortical dysplasia.
OBJECTIVE: To evaluate the sensitivity of a simultaneous whole-head 306-channel magnetoencephalography (MEG)/70-electrode EEG recording to detect interictal epileptiform activity (IED) in a prospective, consecutive cohort of patients with medically refractory epilepsy that were considered candidates for epilepsy surgery. METHODS: Seventy patients were prospectively evaluated by simultaneously recorded MEG/EEG. All patients were surgical candidates or were considered for invasive EEG monitoring and had undergone an extensive presurgical evaluation at a tertiary epilepsy center. MEG and EEG raw traces were analysed individually by two independent reviewers. RESULTS: MEG data could not be evaluated due to excessive magnetic artefacts in three patients (4%). In the remaining 67 patients, the overall sensitivity to detect IED was 72% (48/67 patients) for MEG and 61% for EEG (41/67 patients) analysing the raw data. In 13% (9/67 patients), MEG-only IED were recorded, whereas in 3% (2/67 patients) EEG-only IED were recorded. The combined sensitivity was 75% (50/67 patients). CONCLUSION: Three hundred and six-channel MEG has a similarly high sensitivity to record IED as EEG and appears to be complementary. In one-third of the EEG-negative patients, MEG can be expected to record IED, especially in the case of lateral neocortical epilepsy and/or cortical dysplasia.
Authors: E S Schwartz; D J Dlugos; P B Storm; J Dell; R Magee; T P Flynn; D M Zarnow; R A Zimmerman; T P L Roberts Journal: AJNR Am J Neuroradiol Date: 2008-02-13 Impact factor: 3.825
Authors: Daniel M Goldenholz; Seppo P Ahlfors; Matti S Hämäläinen; Dahlia Sharon; Mamiko Ishitobi; Lucia M Vaina; Steven M Stufflebeam Journal: Hum Brain Mapp Date: 2009-04 Impact factor: 5.038
Authors: Steven M Stufflebeam; Hesheng Liu; Jorge Sepulcre; Naoaki Tanaka; Randy L Buckner; Joseph R Madsen Journal: J Neurosurg Date: 2011-02-25 Impact factor: 5.115
Authors: Naoaki Tanaka; Matti S Hämäläinen; Seppo P Ahlfors; Hesheng Liu; Joseph R Madsen; Blaise F Bourgeois; Jong Woo Lee; Barbara A Dworetzky; John W Belliveau; Steven M Stufflebeam Journal: Neuroimage Date: 2009-12-16 Impact factor: 6.556