Influence of paroxysmal activity on background synchronization in epileptic records

The presence of spikes and sharp waves in the recordings of epileptic patients may contaminate background signal synchronization in different ways. In this Technical Note, we present a simple procedure for assessing whether a particular synchronization method should be used (or not) with data from neurophysiological recordings commonly used to evaluate epilepsy. The information provided by this procedure makes it possible to differentiate true background synchronization from spike synchronization. This issue is particularly relevant when differentiating between the mechanisms underlying the onset of interictal epileptiform discharges and limbic network dynamics.