MEG SPIKE DIPOLE CLUSTERS HAVE DIFFERENT STATISTICS IN DIFFERENT EPILEPSIES
Abstract number :
3.192
Submission category :
Year :
2002
Submission ID :
3475
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Warren S. Merrifield, Massoud Akhtari, Nancy Lopez, Adam N. Mamelak, John C. Mosher, Richard M. Leahy, Ed R. Flynn, Matt L. Riggs, William W. Sutherling. MEG Laboratory, Huntington Medical Research Institutes, Pasadena, CA; Epilepsy and Brain Mapping Prog
RATIONALE: Knowledge of spike characteristics in frontal and temporal epilepsies are important in presurgical evaluation of epilepsy.
METHODS: We analyzed over 300 spikes from over 20 patients. Localizations were confirmed by standard protocol in more than half the patients. All had medically intractable partial epilepsy undergoing presurgical evaluation: There were more temporal than frontal. We recorded all spikes using a 100-SQUID, whole-head Neuromagnetometer (CTF, VSM, Vancouver) in a magnetically shielded chamber (VacuumSchmelze, BTI, 4D-Imaging, San Diego). We used the moving single equivalent current dipole model in a sphere to reconstruct the location and orientation of dipoles. All patients had at least 5 spikes recorded on Magnetoencephalography (MEG) to allow calculation of population characteristics for each patient. Results were analyzed using SPSS[reg] for standard deviation of spatial location, residual variance, amplitude, and orientation.
RESULTS: There was a higher standard deviation of localization (larger spatial spread of the cluster) for frontal versus temporal patients (p=0.04).
CONCLUSIONS: The standard deviation of spatial spread of spike dipole clusters may be a promising statistical parameter to help distinguish temporal versus frontal lobe patients. Other statistical parameters also merit further evaluation.
[Supported by: NIH Grant NS20806]