Development of an Experimental Setup to Investigate the Effect of Skull Discontinuities on the EEG

Abstract

Electroencephalography (EEG) is a non-invasive method to analyze the temporal and spatial extent of neuronal activity in the brain. Skull discontinuities, such as fontanelles of the neonate skull or post-surgical skull conditions, affect EEG diagnostics and EEG-based source reconstruction. However, experimental analyses are rare. The aim of this study is to develop an experimental setup to characterize and quantify the effect of skull discontinuities on the EEG. We constructed an artificial current source (dipole) and a highresolution EEG array suitable for a rodent animal model. The results clearly demonstrate alterations of the EEG caused by a hole in the skull which extend beyond the hole itself. The presence of a return current path through the skull modifies the electric field topography which is in line with theoretic expectations. We conclude that discontinuities in the skull should be accounted for in volume conductor models used in the reconstruction of electric sources in the brain, such as finite element models.