Neural generators of psychogenic seizures: Evidence from intracranial and extracranial brain recordings

Psychogenic seizures (PSs) convincingly mimic seizure phenomena but with no underlying epileptic activity. However, not much is known about their neurophysiological basis. We had the rare opportunity to analyze intracranial brain recordings of PSs occurring besides epileptic seizures (ESs), which identified distinct frequency changes over the parietal cortex. For further validation, we applied topographic frequency analysis to two other patients who presented PSs and ESs during long-term monitoring. The analysis revealed a power decrease in the theta band at the posterior parietal cortex in all three patients during PSs but not during ESs. These changes may reflect disturbed self-referential processing associated with some PSs.