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Coexistence of symptomatic focal and absence seizures: Video‐EEG and EEG‐fMRI evidence of overlapping but independent epileptogenic networks
Author(s) -
Chassag Serge,
Hawko Colin S.,
Bernasconi Andrea,
Gotman Jean,
Dubeau François
Publication year - 2009
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/j.1528-1167.2009.02092.x
Subject(s) - ictal , electroencephalography , neuroscience , epilepsy , eeg fmri , functional magnetic resonance imaging , psychology , magnetic resonance imaging , cortex (anatomy) , generalized epilepsy , medicine , radiology
Summary The distinction between typical absences and hypomotor seizures in patients having frontal lesions is difficult. In focal epilepsy, generalized‐like interictal discharges can reflect either a coexistent generalized epileptic trait or a secondary bilateral synchrony. Using combined measures of the EEG and blood oxygenation level dependent (BOLD) activity, we studied a 50‐year‐old patient with both absence‐like and symptomatic focal motor seizures. Focal activity induced activation in the lesional area and deactivation in the contralateral central cortex. Generalized spike‐and‐wave discharges (GSWDs) resulted also in perilesional activation, and multifocal symmetrical cortical and thalamic activations, and deactivation in associative cortical areas. Although the central cortex was involved during both types of epileptic activity, electroencephalography (EEG)–functional magnetic resonance imaging (fMRI) revealed distinct neuronal networks at the time of the focal or generalized discharges, allowing a clear‐cut differentiation of the generators. Whether the patient had distinct epileptic syndromes or distinct electrographic patterns from the lesional trigger remains debatable.