SEIZURE ANTICIPATION AND MARGINAL PREDICTABILITY IN MESIOBASAL TEMPORAL LOBE EPILEPSY
Abstract number :
1.124
Submission category :
Year :
2002
Submission ID :
3359
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Ivo Drury, Brien J. Smith, Lori A. Schuh, Veronica N. Sosa, Jules Constantinou, Dingzhou Li, Weiping Zhou, Robert Savit. Neurology, Henry Ford Health System, Detroit, Mi; Physics, University of Michigan, Ann Arbor, Mi; Biostatistics, University of Michiga
RATIONALE: To design and use a nonlinear dynamical approach to reliably anticipate seizures in a cohort of patients with mesiobasal temporal lobe epilepsy (MBTLE).
METHODS: We compute a quantity called marginal predictability (MP) for time series of interictal and preictal (within 1 hour of a seizure) scalp EEG. We compare results from one electrode proximate to the ictal onset site to one remote ipsilateral, and to one homologous contralateral electrode. We performed this analysis for 24 seizures and 15 interictal epochs in 7 patients with MBTLE. Statistical validation used Wilcoxon[ssquote]s sum of signed rank test, with sum of positive ranks (SPR) displayed as a function of time.
RESULTS: Interictally, SPRs indicate that MPs for electrodes adjacent to the site of ictal onset are significantly greater than for ipsilateral remote electrodes interictally and until 20-40 minutes before a seizure when they take on similar values. Metaphase space analyses suggest that tight clustering of points (implying autonomy) is correlated with higher MPs at adjacent electrodes.
CONCLUSIONS: We suggest that this dynamical behavior adjacent to the site of ictal onset is an expression of tighter neuronal control that inhibits seizure development and that diminishes as time to clinical onset of a seizure approaches.
[Supported by: 1 RO1 NS36803-01A1]