Evaluation of Methods for Three-Dimensional Localization of Electrical Sources in the Human Brain

Kavanagk, Robert N.; Darcey, Terrance M.; Lehmann, Dietrich; Fender, Derek H.

doi:10.1109/tbme.1978.326339

Cited by 254 publications

(76 citation statements)

References 30 publications

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“…Previous studies have investigated the sensitivity of inverse source localization to factors such as the inclusion of certain anatomical features (e.g., skull [26] and [27]), the accuracy of conductivity values [28]- [30], and the accuracy of lead placement [31], [32]. Some of these studies used the correlation coefficient (CC) as the measure of similarity between two data sets, and have associated the CC in surface potential with the accuracy of source localization.…”

Section: Discussionmentioning

confidence: 99%

Dipole models for the EEG and MEG

Schimpf

Ramon

Haueisen

2002

IEEE Trans. Biomed. Eng.

140

113

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Abstract-The current dipole is a widely used source model in forward and inverse electroencephalography and magnetoencephalography applications. Analytic solutions to the governing field equations have been developed for several approximations of the human head using ideal dipoles as the source model. Numeric approaches such as the finite-element and finite-difference methods have become popular because they allow the use of anatomically realistic head models and the increased computational power that they require has become readily available. Although numeric methods can represent more realistic domains, the sources in such models are an approximation of the ideal dipole. In this paper, we examine several methods for representing dipole sources in finite-element models and compare the resulting surface potentials and external magnetic field with those obtained from analytic solutions using ideal dipoles.Index Terms-Dipole, EEG, finite-element method, MEG, spherical head model.

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Section: Discussionmentioning

confidence: 99%

Dipole models for the EEG and MEG

Schimpf

Ramon

Haueisen

2002

IEEE Trans. Biomed. Eng.

140

113

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“…Some investigators have noted a correlation among scalp ictal EEG patterns (e.g., frequency and evolution) and intracranial seizure origins in the temporal lobe (3-6). We believe that, as has been shown for interictal spikes (7-15), source analysis of the voltage fields of scalp ictal rhythms can provide more information concerning seizure origin and propagation than can visual inspection of EEG traces.Dipole source modeling is one method of estimating the character of cerebral sources underlying a scalp voltage field (16)(17)(18)(19). This mathematical technique attempts to find a theoretical dipole source that can produce a voltage field on a model head that is equivalent to the…”

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confidence: 99%

Continuous Source Imaging of Scalp Ictal Rhythms in Temporal Lobe Epilepsy

Assaf

Ebersole

1997

Epilepsia

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Summary:Purpose: We wished to determine whether continuous EEG source imaging can predict the location of seizure onset with sublobar accuracy in temporal lobe epilepsy (TLE).Methods: We retrospectively analyzed the earliest scalp ictal rhythms, recorded with 23-to 27-channel EEG, in 40 patients with intractable TLE. A continuous source analysis technique with multiple fixed dipoles (Focus 1.1) decomposed the EEG into source components representing the activity of major cortical sublobar surfaces. For the temporal lobe, these were basal, anterior tip, anterolateral, and posterolateral cortex. Ictal EEG onset was categorized according to its most prominent and leading source component. All patients underwent intracranial EEG studies before epilepsy surgery, and all had a successful surgical outcome (follow-up >1 year).Results: Most patients with ictal rhythms having a predominant basal source component had hippocampal-onset seizures, whereas those with seizures with prominent lateral source activity had predominantly temporal neocortical seizure origins. Seizures with a prominent anterior temporal tip source component mostly had onset in entorhinal cortex. Seizures in some patients had several equally large and nearly synchronous source components. These seizures, which could be modeled equally well by a single oblique dipole, had onset predominantly in either entorhinal or lateral temporal cortex. Conclusions:Multiple fixed dipole analysis of scalp EEG can provide information about the origin of temporal lobe seizures that is useful in presurgical planning. In particular, it can reliably distinguish seizures of mesial temporal origin from those of lateral temporal origin. Key Words: Electroencephalography-Dipole-Seizures-Temporal lobe epilepsy.Ictal rhythms are believed to be more reliable than interictal spikes in localizing the epileptogenic focus (1,2). Traditional methods of interpreting scalp ictal EEG have been descriptive and based on the simplistic p i nciple that the electrodes recording the clearest rhythm overlie the seizure focus. Some investigators have noted a correlation among scalp ictal EEG patterns (e.g., frequency and evolution) and intracranial seizure origins in the temporal lobe (3-6). We believe that, as has been shown for interictal spikes (7-15), source analysis of the voltage fields of scalp ictal rhythms can provide more information concerning seizure origin and propagation than can visual inspection of EEG traces.Dipole source modeling is one method of estimating the character of cerebral sources underlying a scalp voltage field (16)(17)(18)(19). This mathematical technique attempts to find a theoretical dipole source that can produce a voltage field on a model head that is equivalent to the

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“…The 2-dipole estimation in the 3-layered concentric spherical model [3,4] is carried out for all samples in a time range of EPs by setting the 3-layered structure, and all electrode positions on the 3rd layer of the sphere. The simplex method [5] is used to solve the inverse problem.…”

Section: Dipole Estimationmentioning

confidence: 99%

Three-Dimensional Display for Multi-sourced Activities and Their Relations in the Human Brain by Information Flow between Estimated Dipoles

Take

Kosugi

Musha

2002

Medical Image Computing and Computer-Assisted Intervention — MICCAI 2002

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Abstract.It is important to show brain activities and their relations visually for the elucidation of the processing mechanism and for the diagnosis of diseases in the human brain. We developed a three-dimensional displaying tool by estimating dipoles to show the activities and by analysing information flow between them to show the relations. At first, we estimate dipoles (via 3-layered concentric spherical model, 2-dipole estimation) from evoked potentials. Secondary, using derived 2 dipole locations and moments as loci and quantities of brain activities, we applied stationary analysis for the information flow between the two time-series of the 1st and the 2nd dipole moments. Therefore, we obtain bi-directional information flows between the neuronal activities localized in 3D space of the brain with respect to somatosensory evoked potentials measured with 21 electrodes arranged according to the international 10-20 standard. Furthermore, we tried non-stationary analysis for the information flow with simulation data.

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Evaluation of Methods for Three-Dimensional Localization of Electrical Sources in the Human Brain

Cited by 254 publications

References 30 publications

Dipole models for the EEG and MEG

Dipole models for the EEG and MEG

Continuous Source Imaging of Scalp Ictal Rhythms in Temporal Lobe Epilepsy

Three-Dimensional Display for Multi-sourced Activities and Their Relations in the Human Brain by Information Flow between Estimated Dipoles

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