title: Predictive modeling of EEG time series for evaluating surgery targets in epilepsy patients.
abstract: During the last 20 years, predictive modeling in epilepsy research has largely been concerned with the prediction of seizure events, whereas the inference of effective brain targets for resective surgery has received surprisingly little attention. In this exploratory pilot study, we describe a distributional clustering framework for the modeling of multivariate time series and use it to predict the effects of brain surgery in epilepsy patients. By analyzing the intracranial EEG, we demonstrate how patients who became seizure free after surgery are clearly distinguished from those who did not. More specifically, for 5 out of 7 patients who obtained seizure freedom (= Engel class I) our method predicts the specific collection of brain areas that got actually resected during surgery to yield a markedly lower posterior probability for the seizure related clusters, when compared to the resection of random or empty collections. Conversely, for 4 out of 5 Engel class III/IV patients who still suffer from postsurgical seizures, performance of the actually resected collection is not significantly better than performances displayed by random or empty collections. As the number of possible collections ranges into billions and more, this is a substantial contribution to a problem that today is still solved by visual EEG inspection. Apart from epilepsy research, our clustering methodology is also of general interest for the analysis of multivariate time series and as a generative model for temporally evolving functional networks in the neurosciences and beyond. Hum Brain Mapp 38:2509-2531, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Neurology, Inselspital\Bern University Hospital\University Bern, Bern, 3010, Switzerland.
authors.forename: Andreas
authors.identifier: 0000-0002-0133-3216
authors.initials: A
authors.lastname: Steimer
authors.affiliation: Department of Neurology, Inselspital\Bern University Hospital\University Bern, Bern, 3010, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Müller
authors.affiliation: Department of Neurology, Inselspital\Bern University Hospital\University Bern, Bern, 3010, Switzerland.
authors.forename: Kaspar
authors.initials: K
authors.lastname: Schindler
mesh_terms: D001921:Brain / Q000503:physiopathology*; D058256:Brain Waves / Q000502:physiology*; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009010:Monte Carlo Method; D010865:Pilot Projects; D013997:Time Factors; D016896:Treatment Outcome
keywords: Bayesian inference; Chow-Liu tree; Hidden Markov Model; distributional clustering; epilepsy; graphical models; predictive modeling; quantitative EEG; rate distortion theory; resective surgery