Combined SEEG and source localisation study of temporal lobe schizencephaly and polymicrogyria.
OBJECTIVE
Type 1 schizencephaly (SZ) is a cerebral malformation characterised by a cleft lined and surrounded by a polymicrogyric cortex, extending from the pial region to the peri-ventricular heterotopia. Our purpose was to combine and compare dipole source imaging technique and Stereo-EEG (SEEG) technique in determining the irritative and epileptogenic zones in a case of type 1 schizencephaly.


METHODS
High-resolution (64-channel) video-EEG with electrical source imaging and SEEG recordings were performed during a pre-surgical evaluation for medically intractable epilepsy.


RESULTS
Anatomo-electro-clinical correlations based on SEEG and source localisation identified two irritative and epileptogenic zones partially overlapping the polymicrogyric cortex surrounding the SZ: an anterior medio-lateral network primarily involving dysplasic limbic structures and a lateral network involving the anterior and middle part of the cleft and polymicrogyric cortex. The most posterior part (at the temporo-parieto-occipital junction) displayed a normal background activity.


CONCLUSIONS
Both epileptogenic and electrophysiologically normal cortices coexisted within the same widespread malformation: only the anterior part belonged to the anterior medio-lateral epileptogenic network defined by the SEEG.


CONCLUSIONS
In cases of widespread cortical malformation such as SZ, source localization techniques can help to define the irritative zone and relevant targets for SEEG.
Maillard
L
L
Service de Neurologie, Centre Hospitalier Universitaire de Nancy, France. l.maillard@chu-nancy.fr
Koessler
L
L
Colnat-Coulbois
S
S
Vignal
J-P
JP
Louis-Dorr
V
V
Marie
P-Y
PY
Vespignani
H
H
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008032:Limbic System / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D054220:Malformations of Cortical Development / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013238:Stereotaxic Techniques; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18