Establishing a Framework to Transition High Frequency Oscillations to Routine Clinical Care in Patients with Focal Epilepsy

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atmire.migration.oldid4498
dc.contributor.advisorFederico, Paolo
dc.contributor.authorSpring, Aaron Michael
dc.contributor.committeememberAgha-Khani, Yahya
dc.contributor.committeememberGotman, Jean
dc.contributor.committeememberProtzner, Andrea B.
dc.contributor.committeememberStarreveld, Yves Pieter
dc.contributor.committeememberTeskey, Gordon Campbell
dc.date.accessioned2016-06-17T16:47:04Z
dc.date.available2016-06-17T16:47:04Z
dc.date.issued2016
dc.date.submitted2016en
dc.description.abstractHigh frequency oscillations (HFOs), characteristic oscillations observable using electroencephalography (EEG), are a promising and specific marker of the epileptogenic zone (EZ). However, there remain several obstacles to the implementation of HFOs as a prospective tool in the treatment of epilepsy. The identification of HFOs lacks universal standards and demands large time commitments from epileptologists. Therefore, this work involved the implementation and validation of novel frameworks for identifying HFOs, and for evaluating these HFOs as markers of the EZ. An epoched framework was implemented to facilitate the visual identification of HFOs, through which poor reliability was observed between reviewers. Furthermore, it was found that the temporal efficiency of visually evaluating HFOs within the epoched framework marked a substantial improvement over previously reported evaluation times. Using generalizability theory, it was then extended to determine effective methods of achieving highly reliable visual HFO evaluations, which included averaging ratings from at least 12 visual reviewers, or employing a training paradigm to increase the correlation of the ratings across reviewers. A novel surrogate marker (uGIC) of HFO activity was implemented and found to be correlated with HFOs detected algorithmically at low or high thresholds, all of which were found to be markers of the seizure onset zone overall. A retrospective framework was implemented to improve the accuracy of delineating the margins of resection with respect to EEG electrodes. A deformable method of image co-registration and a hybrid method of estimating electrode shift were shown to more effectively compensate for post-surgical shifts in brain anatomy. Resecting the uGIC or detected HFOs were found to have a positive effect on seizure freedom. Notably, the inclusion of lower-threshold oscillations was beneficial in facilitating the visual evaluation of HFOs, and in the identification of the EZ. Together, the findings of the studies undertaken herein provide a comprehensive framework to serve as the basis for transitioning high frequency oscillations to a feasible and meaningful part of the routine pre-surgical work-up in patients with focal epilepsy.en_US
dc.identifier.citationSpring, A. M. (2016). Establishing a Framework to Transition High Frequency Oscillations to Routine Clinical Care in Patients with Focal Epilepsy (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25954en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/25954
dc.identifier.urihttp://hdl.handle.net/11023/3062
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectNeuroscience
dc.subjectHealth Sciences
dc.subjectMedicine and Surgery
dc.subject.classificationEpilesyen_US
dc.subject.classificationGeneralizability Theoryen_US
dc.subject.classificationHigh Frequency Oscillations (HFOs)en_US
dc.subject.classificationElectroencephalography (EEG)en_US
dc.subject.classificationIntracranial EEGen_US
dc.subject.classificationSurgeryen_US
dc.subject.classificationInterrater Reliabilityen_US
dc.subject.classificationlocalizationen_US
dc.subject.classificationBiomarkersen_US
dc.subject.classificationSurrogate Markersen_US
dc.subject.classificationVisual Reviewen_US
dc.subject.classificationAutomated Detection Algorithmen_US
dc.titleEstablishing a Framework to Transition High Frequency Oscillations to Routine Clinical Care in Patients with Focal Epilepsy
dc.typedoctoral thesis
thesis.degree.disciplineNeuroscience
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
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