Long-Term Effect of Unilateral Intrahippocampal Kainic Acid Injection and Gamma-Knife Treatment on the Interictal and Ictal EEG of an Animal Model of Temporal Lobe Epilepsy
Abstract number :
1.040
Submission category :
Year :
2000
Submission ID :
1412
Source :
www.aesnet.org
Presentation date :
12/2/2000 12:00:00 AM
Published date :
Dec 1, 2000, 06:00 AM
Authors :
Andrew Pan, Janice Lyons, Shinji Kondo, Imad M Najm, John Greskovitch, Takaheru Kunieda, Gene Barnett, William E Bingaman, Hans O L ders, Cleveland Clin Fdn, Cleveland, OH.
RATIONALE: Intrahippocampal kainic acid (IHK) in rats lead to chronic seizure activity similar to human temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS). Gamma-knife (GK) irradiation is emerging as a treatment modality for patients with TLE due to HS. We studied the interictal and ictal electroencephalographical (EEG) changes after unilateral IHK injection and the effect of GK treatment on this. METHODS: Four Sprague-Dawley rats underwent stereotactic unilateral IHK injection. Continuous video-EEG monitoring was first performed 14.5 months later using bilateral intrahippocampal depth electrodes. GK treatment with a single dose of 25Gy was stereotactically administered to the ipsilateral hippocampus. The rats were then monitored within one week and 6 months after GK treatment. EEG recordings of these rats were compared with that of 3 normal rats subjected to monitoring with bihippocampal depth electrodes. RESULTS: EEG of 3 rats that survived the GK treatment showed interictal and ictal EEG seizure activity arising from both ipsilateral and contralateral hippocampi prior to GK treatment. Contralateral interictal discharges (IED) were more abundant than ipsilateral discharges (31 spikes/hr vs 2.67 spikes/hr). Mean IEDs pre-GK treatment was 35.56 spikes/hr while seizures occurred at a mean rate of 9.11/hr. A week post-GK treatment, IEDs decreased to 18.29 spikes/hr though the rate of seizure occurrence remained similar (12/hr). IEDs and EEG seizures decreased to 3.9 spikes/hr and 5.2/hr respectively 6 months post-GK treatment. Contralateral IEDs and EEG seizure activity were noted to decrease with ipsilateral GK treatment. CONCLUSIONS: Our results show evidence of a potential beneficial effect of GK treatment on both the interictal and ictal EEG manifestation (both ipsilateral and contralateral) of an animal model of chronic temporal lobe epilepsy.