%0 Journal Article
%T Spontaneous EEG-Functional MRI in Mesial Temporal Lobe Epilepsy: Implications for the Neural Correlates of Consciousness
%A Zheng Wang
%A Loretta Norton
%A R. Matthew Hutchison
%A John R. Ives
%A Seyed M. Mirsattari
%J Epilepsy Research and Treatment
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/385626
%X The combination of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has been shown to have great potential for providing a greater understanding of normal and diseased states in both human and animal studies. Simultaneous EEG-fMRI is particularly well suited for the study of epilepsy in that it may reveal the neurobiology of ictal and interictal epileptiform discharges and noninvasively localize epileptogenic foci. Spontaneous, coherent fluctuations of neuronal activity and the coupled hemodynamic responses have also been shown to provide diagnostic markers of disease, extending our understanding of intrinsically structured ongoing brain activity. Following a short summary of the hardware and software development of simultaneous EEG-fMRI, this paper reviews a unified framework of integrating neuronal and hemodynamic processes during epileptic seizures and discusses the role and impact of spontaneous activity in the mesial temporal lobe epilepsies with particular emphasis on the neural and physiological correlates of consciousness. 1. Introduction Temporal lobe epilepsy (TLE) manifests with partial seizures whose semiology can reflect a dynamic interplay among several anatomical divisions of the temporal lobe, in addition to their sites of origin [1]. Approximately 20%¨C30% of TLE patients are intractable to treatment with antiepileptic drugs though they may still benefit from surgical resection of the epileptogenic focus (EF) [2]. It is, therefore, essential to localize the EF in patients with focal epilepsy and to discern the large-scale cortical and subcortical networks involved in seizure generation. This is best achieved with the use of simultaneous, multimodal techniques that are able to elucidate complex functional relationships through converging or parallel operations. The development of electroencephalogram (EEG) recording of epileptic patients inside a magnetic resonance imaging (MRI) scanner was largely driven by the necessity of localizing and delineating mesial or deeply originating EF electrically and metabolically during presurgical evaluation [3¨C7]. The concurrent measures allow for the monitoring of abnormal hypersynchronous events in the EF, as well as the full-brain coverage of variations in blood flow and oxygenation in response to epileptic discharges conducive to a wide range of research applications within epileptology. Simultaneous EEG-fMRI has the potential to become a routine diagnostic test, complementing the diagnostic accuracy of clinical acumen and EEG to greatly improve medical and surgical
%U http://www.hindawi.com/journals/ert/2012/385626/