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Document Type:Latin Dissertation
Language of Document:English
Record Number:52374
Doc. No:TL22328
Call number:‭3370867‬
Main Entry:Yue Li
Title & Author:Epilepsy and the use of feedback stimulation to control seizuresYue Li
College:Illinois Institute of Technology
Date:2009
Degree:Ph.D.
student score:2009
Page No:113
Abstract:Intractable epilepsy that remains resistant to drug treatment is a significant public health problem with very few alternative therapeutic options besides surgery. The goal of this research is to investigate hypothesized mechanisms of epileptogenesis and to explore innovative treatments of seizures. A computational model of connections in a hippocampal slice preparation was constructed including two recently-reported distinct inhibitory feedback circuits. Simulation result showed that decreasing dendritic inhibition led to highly localized seizure-like bursting similar to that which occurs experimentally under GABAergic blockade. In contrast, increasing axosomatic inhibition which resulted in decreased neuronal coupling would also caused similar seizure-like bursting as has been observed in some epileptic patients. These results shed light on a possible pathway in which decreased synchronization could be a trigger for inducing epileptiform activity. Meanwhile, our laboratory has been exploring electrical stimulation protocols to modulate and ideally terminate epileptic seizures. A "closed-loop" feedback control technique was utilized to adaptively generate stimulation protocols based on neurodynamics. Multipolar electrodes were stereotactically implanted into motor cortex of Sprague-Dawley rats. Multi-channel intracranial electroencephalograms (EEGs) and surface EEGs were simultaneously recorded. Spontaneous episodic seizure activity was induced by focal injection of penicillin. The initial set of protocols recorded focal EEG which was processed and fed back through a proportional controller as a template for electrical current simulation. Experimental results showed suppression although not reversion of epileptic seizures in the in vivo rat brain. A second set of protocols sought to explore phase resetting as a means to revert seizures. The focal intracranial EEG was analyzed to calculate an "optimal" timing for delivering stimulation. Dominant neural frequencies were extracted in order to keep stimulation pulses phase-locking to brain activity. A hypothesis for applying such phase resetting protocols is that precisely timed current stimuli could potentially disrupt the highly coherent neural activation at the focus. Experiments showed complex results suggesting it may provide a possible means for new stimulation protocols to terminate seizures, yet further exploration of such technique is needed.
Subject:Applied sciences; Biological sciences; Epilepsy; Feedback stimulation; Seizures; Seizure control; Neurosciences; Biomedical engineering; 0541:Biomedical engineering; 0317:Neurosciences
Added Entry:D. J. Mogul
Added Entry:Illinois Institute of Technology