High-resolution EEG (HR-EEG) and magnetoencephalography (MEG)

High-resolution EEG (HR-EEG) and magnetoencephalography (MEG) allow the recording of spontaneous or evoked electromagnetic brain activity with excellent temporal resolution. Data must be recorded with high temporal resolution (sampling rate) and high spatial resolution (number of channels). Data analyses are based on several steps with selection of electromagnetic signals, elaboration of a head model and use of algorithms in order to solve the inverse problem. Due to considerable technical advances in spatial resolution, these tools now represent real methods of ElectroMagnetic Source Imaging. HR-EEG and MEG constitute non-invasive and complementary examinations, characterized by distinct sensitivities according to the location and orientation of intracerebral generators. In the presurgical assessment of drug-resistant partial epilepsies, HR-EEG and MEG can characterize and localize interictal activities and thus the irritative zone. HR-EEG and MEG often yield significant additional data that are complementary to other presurgical investigations and particularly relevant in MRI-negative cases. Currently, the determination of the epileptogenic zone and functional brain mapping remain rather less well-validated indications. In France, in 2014, HR-EEG is now part of standard clinical investigation of epilepsy, while MEG remains a research technique.

[1]  C. Baumgartner.  Controversies in clinical neurophysiology. MEG is superior to EEG in the localization of interictal epileptiform activity: Con , 2004, Clinical Neurophysiology.

[2]  C. Daumas-Duport,et al.  Stereoelectroencephalography in focal cortical dysplasia: a 3D approach to delineating the dysplastic cortex. , 2000, Brain : a journal of neurology.

[3]  A. Sakamoto,et al.  Clinical Features of Patients with Posterior Cortex Epilepsies and Predictors of Surgical Outcome , 2005, Epilepsia.

[4]  S. Lehéricy,et al.  Human brain mapping in dystonia reveals both endophenotypic traits and adaptive reorganization , 2001, Annals of neurology.

[5]  François Mauguière,et al.  The value of magnetoencephalography for seizure-onset zone localization in magnetic resonance imaging-negative partial epilepsy , 2013, Brain : a journal of neurology.

[6]  Evelien Carrette,et al.  Recording temporal lobe epileptic activity with MEG in a light-weight magnetic shield , 2011, Seizure.

[7]  L. Koessler,et al.  Spatial localization of EEG electrodes , 2007, Neurophysiologie Clinique/Clinical Neurophysiology.

[8]  Kristen Riley,et al.  Magnetic source imaging versus intracranial electroencephalogram in epilepsy surgery: A prospective study , 2006, Annals of neurology.

[9]  J. Engel,et al.  Ictal magnetic source imaging as a localizing tool in partial epilepsy , 2002, Neurology.

[10]  Christoph M. Michel,et al.  Epileptic source localization with high density EEG: how many electrodes are needed? , 2003, Clinical Neurophysiology.

[11]  Claudio Pollo,et al.  Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients , 2011, Brain : a journal of neurology.

[12]  L. Vaina,et al.  Mapping the signal‐to‐noise‐ratios of cortical sources in magnetoencephalography and electroencephalography , 2009, Human brain mapping.

[13]  Al Bartolucci,et al.  Effect of epilepsy magnetic source imaging on intracranial electrode placement , 2009, Annals of neurology.

[14]  R. Kristeva-Feige,et al.  Localization of Interictal Delta and Epileptiform EEG Activity Associated with Focal Epileptogenic Brain Lesions , 2001, NeuroImage.

[15]  M. Murray,et al.  EEG source imaging , 2004, Clinical Neurophysiology.

[16]  P Berg,et al.  Multiple source analysis of interictal spikes: goals, requirements, and clinical value. , 1999, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[17]  C. Michel,et al.  EEG Source Imaging in Pediatric Epilepsy Surgery: A New Perspective in Presurgical Workup , 2006, Epilepsia.

[18]  Al Bartolucci,et al.  Functional imaging: I. Relative predictive value of intracranial electroencephalography , 2008, Annals of neurology.

[19]  L. Koessler,et al.  EEG–MRI Co-registration and Sensor Labeling Using a 3D Laser Scanner , 2010, Annals of Biomedical Engineering.

[20]  J Gotman,et al.  Reliability of dipole models of epileptic spikes , 1999, Clinical Neurophysiology.

[21]  J. Girvin,et al.  Epilepsy surgery in the posterior cortex , 1991, Annals of neurology.

[22]  Jean-Michel Badier,et al.  Source localization of ictal epileptic activity investigated by high resolution EEG and validated by SEEG , 2010, NeuroImage.

[23]  A. Papanicolaou,et al.  Optimizing estimation of hemispheric dominance for language using magnetic source imaging , 2011, Brain Research.

[24]  G. Barkley,et al.  Controversies in neurophysiology. MEG is superior to EEG in localization of interictal epileptiform activity: Pro , 2004, Clinical Neurophysiology.

[25]  J. Sarvas.  Basic mathematical and electromagnetic concepts of the biomagnetic inverse problem. , 1987, Physics in medicine and biology.

[26]  A. Gevins,et al.  The future of the EEG and MEG. , 1993, Electroencephalography and clinical neurophysiology.

[27]  R M Leahy,et al.  EEG source localization and imaging using multiple signal classification approaches. , 1999, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[28]  M Reite,et al.  The human magnetoencephalogram: some EEG and related correlations. , 1976, Electroencephalography and clinical neurophysiology.

[29]  Patrick Chauvel,et al.  From Perception to Recognition Memory: Time Course and Lateralization of Neural Substrates of Word and Abstract Picture Processing , 2011, Journal of Cognitive Neuroscience.

[30]  S. Baillet,et al.  Localization of realistic cortical activity in MEG using current multipoles , 2004, NeuroImage.

[31]  John S Ebersole,et al.  American Clinical Magnetoencephalography Society Clinical Practice Guideline 1: Recording and Analysis of Spontaneous Cerebral Activity* , 2011, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[32]  Fabrice Bartolomei,et al.  Electric Source Imaging in Temporal Lobe Epilepsy , 2004, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[33]  L F Quesney,et al.  Usefulness of focal rhythmic discharges on scalp EEG of patients with focal cortical dysplasia and intractable epilepsy. , 1996, Electroencephalography and clinical neurophysiology.

[34]  Joachim Gross,et al.  Good practice for conducting and reporting MEG research , 2013, NeuroImage.

[35]  Robert C. Knowlton,et al.  American Clinical Magnetoencephalography Society Clinical Practice Guideline 3: MEG–EEG Reporting* , 2011, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[36]  S Sveinbjornsdottir,et al.  Parietal and Occipital Lobe Epilepsy: A Review , 1993, Epilepsia.

[37]  Georgia Ramantani,et al.  Electrical source imaging in cortical malformation–related epilepsy: A prospective EEG‐SEEG concordance study , 2014, Epilepsia.

[38]  M. Hämäläinen,et al.  Realistic conductivity geometry model of the human head for interpretation of neuromagnetic data , 1989, IEEE Transactions on Biomedical Engineering.

[39]  Taufik Valiante,et al.  EEG and MEG in mesial temporal lobe epilepsy: Where do the spikes really come from? , 2011, Clinical Neurophysiology.

[40]  J. Ebersole,et al.  Intracranial EEG Substrates of Scalp EEG Interictal Spikes , 2005, Epilepsia.

[41]  Fabrice Bartolomei,et al.  Electric Source Imaging in Frontal Lobe Epilepsy , 2006, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[42]  Jacques Felblinger,et al.  Automatic localization and labeling of EEG sensors (ALLES) in MRI volume , 2008, NeuroImage.

[43]  François Mauguière,et al.  Towards source volume estimation of interictal spikes in focal epilepsy using magnetoencephalography , 2012, NeuroImage.

[44]  Heidi E Kirsch,et al.  American Clinical Magnetoencephalography Society Clinical Practice Guideline 2: Presurgical Functional Brain Mapping Using Magnetic Evoked Fields* , 2011, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[45]  J. Vrba,et al.  Signal processing in magnetoencephalography. , 2001, Methods.

[46]  R. Wennberg,et al.  Source localization of mesial temporal interictal epileptiform discharges: Correlation with intracranial foramen ovale electrode recordings , 2005, Clinical Neurophysiology.

[47]  F. Mauguière,et al.  Topographical reliability of mesio-temporal sources of interictal spikes in temporal lobe epilepsy. , 1998, Electroencephalography and clinical neurophysiology.

[48]  M Gavaret,et al.  [High-resolution EEG (HR-EEG) and magnetoencephalography (MEG)]. , 2008, Neuro-Chirurgie.

[49]  Fabrice Bartolomei,et al.  Stereoelectroencephalography in presurgical assessment of MRI-negative epilepsy. , 2007, Brain : a journal of neurology.

[50]  H. Otsubo,et al.  Magnetoencephalographic localization in pediatric epilepsy surgery: Comparison with invasive intracranial electroencephalography , 1999, Annals of neurology.

[51]  L. Koessler,et al.  Combined SEEG and source localisation study of temporal lobe schizencephaly and polymicrogyria , 2009, Clinical Neurophysiology.

[52]  Paul Boon,et al.  Magnetoencephalography Is More Successful for Screening and Localizing Frontal Lobe Epilepsy than Electroencephalography , 2007, Epilepsia.

[53]  A. Genow,et al.  Epilepsy surgery, resection volume and MSI localization in lesional frontal lobe epilepsy , 2004, NeuroImage.

[54]  D. Cohen.  Magnetoencephalography: Evidence of Magnetic Fields Produced by Alpha-Rhythm Currents , 1968, Science.