Brain Mapping of Cortical Epileptogenic Zones and Their EEG Source Localization

摘要

Electroencephalography has an important role in diagnoses of various brain disorders. Among these disorders, Epilepsy is the most common as 1% of world population is suffering from it. Being a neuroimaging technique, EEG is utilized in testing epilepsy (or seizures) while mapping the neural activity of the brain. EEG not only measures the electrical activity and continuous cortical changes with better time resolution but it also investigates the known or predicted seizures or epilepsy issues in the normal and abnormal subjects. The objective of this paper is to investigate the seizures, spikes or predicted epilepsy issues and their source localization in the suspected epilepsy subject while sleeping in the night. In the results, it is found that several sharp spikes or seizures are found in the entire EEG data particularly in the frontal sensory part of the brain. In order to investigate the seizures or spikes and their source localization, the EEG epileptic suspected data is firstly cleaned from the noises, and artifacts and other unwanted harmonics. This requires several pre-processing steps for such as cleaning, averaging, referencing, filtering, epoching and coupling the anatomical structure with the sensors and improving signal-to-noise ratio (SNR). The analysis shows that left fronto-central part of the brain with the high amplitudes at the position of the electrodes (FC1, Cz) carries the sharp waves, poly-spikes and bursts of beta band activity especially during the sleep of the patient. This area is also located with the fixing goodness value above than 95% in a given time slot.