Usefulness of EEG Dipole Analysis in Children with Localization-Related Epilepsy.
Abstract number :
1.188
Submission category :
Year :
2001
Submission ID :
2706
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
A. Ochi, M.D., Neurology, The Hospital for Sick Children, Toronto, ON, Canada; H. Otsubo, M.D., Neurology, The Hospital for Sick Children, Toronto, ON, Canada; S. Chitoku, M.D., Neurology, The Hospital for Sick Children, Toronto, ON, Canada; R. Sharma, RE
RATIONALE: EEG dipole analysis has been used for presurgical evaluation to localize epileptogenic zone proved by electrocorticographical findings in patients with intractable epilepsy. We analyzed EEG dipole localizations in children with possible localization-related epilepsy to evaluate whether EEG dipoles provide additional useful information along with the results obtained from prolonged scalp video EEG recordings.
METHODS: Interictal EEG dipole analysis was performed in 48 children with possible localization-related epilepsy. These patients were admitted for prolonged scalp video EEG monitoring between September 1997 and April 2001. Scalp EEG was recorded using 10-20 international system and subtemporal electrodes for temporal lobe epilepsy. Dipoles were localized using interictal spikes, a single moving dipole and 3-shell spherical head model. We compared the localization of dipoles with goodness of fit [gt]95%, to the interictal EEG findings and the following managements.
RESULTS: In 32 of 48 patients (66.7%), dipoles showed lateralized and localized epileptic region. Thirteen of 32 showed both interictal spikes and dipoles in a single epileptic region. Diffusely lateralized interictal spikes were observed in 16 patients, among them 11 patients had dipoles in one lobe and 5 showed dipoles in the neighboring two lobes. In the other three patients with bilateral interictal spikes, dipoles were predominantly localized in one hemisphere. In 12 patients (25.0%) who had diffuse hemispheric (1), bilateral (10) and generalized (1) interictal discharges, dipoles were localized diffusely in one hemisphere (1), bilateral (7) and multiple regions (4). Inadequate few dipoles were found in 4 patients (8.3%).
CONCLUSIONS: Interictal EEG dipole analysis provided further useful information for localization of epileptogenesis when interictal spikes were seen over the unilateral hemispheric region in pediatric surgical candidates. Dipole analysis of bilateral interictal EEG discharges did not show lateralization of epileptogenic hemisphere in most cases.