Human somatosensory evoked potential dipoles: how accurate are the localizations?

In contrast to studies describing human magnetoencephalographic fields, the literature on human electrophysiologic dipoles has paid relatively little attention to the spatial variability of dipole solutions. Based on studies of six normal subjects repeated on three different days, it was found that electrophysiologic dipoles calculated from scalp somatosensory evoked potentials had a variability similar to that reported for magnetoencephalography. The localization accuracy of the technique has yet to be demonstrated for natural neurophysiologic dipoles. Improvements in models and registration with MRI, and confirmation from independent techniques will likely lead to improvements in accuracy.