1. PFA may be a reflection of proximity of the epileptogenic zone to the recording electrodes. Seizures arising from the lateral frontal convexity began with repetitive epileptiform activity, whereas seizures of patients with mesial lesions more often began with rhythmic theta activity. PFA was observed at the onset of seizures arising from the inferior aspect of the supplementary sensorimotor area and cingulate gyrus, where the distance between the nearest scalp electrode and the generator is great. PFA was virtually never observed at the onset or during the course of MTLE seizures. Therefore, PFA is generated during neocortical ictal activation.41,258–260 Its presence is not primarily dependent on the proximity of the recording electrode to the epileptic generator. Rather, the presence of paroxysmal fast activity may be an expression of propagation from the epileptogenic zone to areas underlying the involved scalp electrodes, or may be influenced by other factors such as a pathologic substrate.41 Incomplete removal of epileptic activity as defined by subdural EEG is likely to result in seizure recurrence.261,262 Interictal and ictal paroxysmal fast activity is reported to be more specific for FCD than other pathologies.263–265 The localized burst, continuous, or nearly continuous pattern of epileptiform discharges on ECoG was associated with the FCD lesion.73 Interictal PFA and runs of repetitive spikes correlated with the ictal onset zone, whereas isolated spikes did not, and incomplete resection of interictal PFA correlated with seizure recurrence.261
Source: Focal Epilepsy, Atlas of Pediatric EEG
Citation: Laoprasert P. Atlas of Pediatric EEG; 2011 Available at: Accessed: October 26, 2017
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