Ricerc@Sapienza

Introduction: Scalp-recorded EEG signals can be used to calculate the locations of electrical sources in the brain. This procedure can improve the investigation of the functional organization of the human brain, exploiting the high temporal resolution of EEG to follow the temporal dynamics of information processing. As for today, the uncertainties about the effects of in-homogeneities due to brain lesions preclude the adoption of EEG functional mapping on patients with lesioned brain. Objectives: The aim of this work is to quantify the accuracy of distributed source localization methods in recovering extended sources of activated neural activity when lesions are introduced. Methods: A realistic brain structural connectivity network will be used to simulate brain neuronal dynamics by a system of neural masses coupled to one another with strengths proportional to the structural properties at each edge. Different structural lesions obtained removing nodes and connections within spatially defined regions will be introduced to simulate altered dynamics of the brain activity. For each simulated lesion and equivalent cerebral activity, pathological four-layer Boundary Element Method head models will be developed and forward and inverse calculations will be carried out to quantify localization errors. The simulation analysis will allow to determine the sensitivity of the inverse solution to both geometrical and conductivity parameters of the lesion. Expected results: These findings will allow to increase the confidence in source localization procedures, maintaining and assuring the accuracy of solutions of EEG inverse problems also in presence of a lesion. The validity of the developed methodology will be tested by comparing reconstructed neural activity from already available simultaneous extra- and intra-cranial real EEG data of epilepsy patients with brain lesion.