MAGNETOENCEPHALOGRAPHIC FEATURES ASSOCIATED WITH CORTICAL MIGRATION DISORDER
Abstract number :
1.207
Submission category :
Year :
2002
Submission ID :
3284
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Hideaki Ishibashi, Panagiotis G. Simos, James W. Wheless, Wenbo Zhang, Howard L. Kim, James E. Baumgartner, Eduardo M. Castillo, William W. Maggio, Vijay Maggio, Andrew C. Papanicolaou. Department of Neurosurgery, The University of Texas, Houston, TX; Dep
RATIONALE: Magnetoencephalography (MEG) is a novel noninvasive technique for presurgical localization of the epileptogenic zone in patients with epilepsy. The presence of interictal epileptogenic bursting activity on the electroencephalography (EEG) is marker of the underlying pathology in intractable epilepsy associated with cortical migration disorder. The present study was designed to investigate the significance and localization accuracy of epileptogenic bursting activity detected by MEG in 20 patients with cortical migration disorders (focal cortical dysplasia, tuberous sclerosis, hemimegalencephaly and schizencephaly).
METHODS: We reviewed 20 patients (focal cortical dysplasia -7, tuberous sclerosis -7, hemimegalencephaly -4 and schizencephaly [ndash]3). Equivalent single dipole modeling was applied to interictal epileptogenic bursting activity which were easily distinguished from background activity, more easily with MEG than EEG.
RESULTS: Interictal epileptogenic activities were seen in 4 (57%) patients with focal cortical dysplasia, 5 (71%) with tuberous sclerosis, 4 (100%) with hemimegalencephaly and 3 (100%) with schizencephaly. In focal cortical dysplasia, the localization of these activities corresponded with the electrocorticography. In tuberous sclerosis, interictal epileptogenic bursting activities were frequently bisynchronous when cortical tubers were seen in the frontal lobes. In such cases, dipole localization could hardly be detected. Hemimegalencephaly patients[scquote] cortical malformation was maximal in the posterior part of the hemisphere and the dipole localization corresponded with the MRI findings. In schizencephaly patients, one had dipole localization around the open cleft, however the other two patients showed dipoles originating from the temporal lobe ipsilateral to the lesion.
CONCLUSIONS: Existence of interictal epileptogenic bursting activity on MEG confirms that cortical migration abnormalities are highly epileptogenic. In children with tuberous sclerosis and schizencephaly, further assessment may be needed prior to epilepsy surgery.
[Supported by: NIH Grant R01 NS37941 to Dr. Andrew C. Papanicolaou]