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Jean-Michel Badier

Publications and source records attributed to Jean-Michel Badier.

4 recordsLinked to original sources
PubMed2006

Electric source imaging in frontal lobe epilepsy.

The objective of this study was to determine the validity of interictal spike (IIS) source localization in frontal lobe epilepsies (FLE) using stereoelectroencephalography as a validating method. Ten patients with drug-resistant FLE were studied with high-resolution EEG and stereoelectroencephalography. Sixty-four scalp channels, a realistic head model, and different algorithms were used. For each patient, the intracerebral interictal distribution was studied and classified into one of three groups: lateral, medial, and mixed (latero-medio-basal). Surface IIS were abundant or subcontinuous for 8 of 10 FLE patients. In lateral and medial groups, intracerebral interictal activities were accurately localized. In the mixed group, source localizations designated a part of the intracerebral interictal distribution. A high degree of source localization accuracy is obtained in FLE. False-positive results were never obtained, but the extent of interictal activity could be underestimated by source localization results. Geometrical and cytoarchitectonic characteristics of the generator appear crucial to explain why medial frontal IIS (anterior para-cingulate gyrus and anterior cingulate gyrus) may be localizable whereas only the lateral orbitofrontal IIS seems to be localizable.

Adolescent↗
PubMed2005

Hemispheric lateralization of voice onset time (VOT) comparison between depth and scalp EEG recordings.

Auditory-evoked potential (AEP)s elicited to French-language voiced stop consonant (/ba/) and voiceless stop consonant (/pa/) were studied in non-language-impaired epileptic patients and non-epileptic volunteers. First, depth AEPs recorded from the primary auditory cortex during pre-surgical exploration and scalp AEPs recordings using high resolution EEG (HR EEG-64 channels scalp EEG) were compared in the same patients. Both methods indicated that the processing of voiced and voiceless consonants was based on a temporal auditory coding. /Ba/ elicited a first complex (N1) at the onset of voicing and a second component [release component (RC)] time-locked to release. This processing took place specifically in the left primary auditory cortex. Source modeling of the RC showed that a left-greater-than-right amplitude of source probes (SP) both in epileptic patients with left-hemispheric language dominance [established by means of invasive tests (WADA test) and/or clinical data] and right-handed non-epileptic subjects. Our data suggest that the processing of VOT is related to hemispheric dominance for language and that scalp-recorded AEPs may represent an effective, non-invasive method to establish hemispheric dominance for language in clinical settings. This procedure could complement existing methods and could help to detect the dissociation between receptive and expressive language sometimes observed in patients with epilepsy.

Acoustic Stimulation↗
PubMedDate not supplied

Electric source imaging in temporal lobe epilepsy.

The objective of this study was to determine the validity of interictal spike (IIS) source localization in temporal lobe epilepsies (TLE) using stereoelectroencephalography as a validating method. Twenty patients with drug-resistant TLE were studied with high-resolution EEG and stereoelectroencephalography. Sixty-four scalp channels, a realistic head model, and different algorithms were used. For each patient, the intracerebral interictal distribution was studied and classified into one of three groups: L (mainly lateral), ML (mediolateral), and M (medial). In group L (three patients), surface IIS were recorded with a high signal-to-noise ratio. Source localizations designated all or part of the intracerebral interictal distribution. In group ML (11 patients), 8 patients had surface IIS, only 5 of which were localizable. High-resolution EEG permitted localization of the more lateral portion and definition of its rostrocaudal extension. A common pattern was identified in three patients with a predominant role of the temporal pole. In group M (six patients), four patients had rare surface IIS, none of which were localizable. Surface EEG does not record IIS limited to medial temporal lobe structures. In TLE with a mediolateral or a lateral interictal distribution, only the lateral component is detectable on surface EEG and accurately localizable by source localization tools.

Adolescent↗