Effect of skull discontinuities on MEG and EEG: Experimental results
نویسندگان
چکیده
While the effect of skull discontinuities on electric surface potentials has been addressed frequently, only very few studies exist on the influence of such discontinuities on the magnetic field. We investigated the effect of holes in the skull on the simultaneously recorded electroencephalogram and magnetoencephalogram. Measurements were carried out in rabbits with two holes in the skull and an artificial current dipole positioned at various distances underneath one hole. Our results demonstrate that both EEG and MEG were significantly influenced by the holes with maximum MAGrel values of above 300% for EEG and above 30% for MEG. The strongest influence was observed when the source is under the edge of the hole. We conclude that discontinuities in the skull should be accounted for in volume conductor models used in the reconstruction of amplitudes of brain sources from EEG and MEG, particularly in infants, children and patients with post-surgical skull conditions.
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