The effect of fontanel on scalp EEG potentials in the neonate.

highlights abstract Objective: To define how fontanels affect scalp EEG potentials in neonates. Method: Realistic finite element method head models were generated with and without fontanels. The electrical activity of the whole cortex was simulated using distributed 54,620 concurrently active cortical dipoles with a uniform random distribution of current densities (0-40 lA/cm 2 ). The overall effects of fontanels on scalp potentials were calculated from finite element forward solution in the vicinity the fon- tanel region by relative difference measure (RDM ⁄ ) and magnification factor (MAG), and the skull conduc- tivity was systematically varied from 0.003 to 0.3 S/m. Results: The neonatal scalp EEG topographies are comparable in models with and without fontanels, with highest amplitudes directly above the anterior fontanel. Quantitatively, comparison of these models elic- its negligible differences (RDM ⁄ � 2% and MAG � 1.0). However, fontanel contribution to scalp potential was shown to increase sharply with decreases in skull conductivity. Conclusions: These results suggest that fontanels may affect neonatal scalp EEG much less than tradition- ally assumed, and the effect is strongly dependent on skull conductivity. Significance: Most neonatal EEG studies can be adequately performed without assuming distortions by fontanels.