How variable are psychogenic nonepileptic seizures? A retrospective semiological study.

PURPOSE: To classify patients with psychogenic nonepileptic seizures (PNES) according to a recently proposed classification system and investigate the variability of PNES semiology.

METHODS

We retrospectively investigated all patients with PNES admitted at the Jefferson Comprehensive Epilepsy Center from 2012 through 2016. We classified their seizures after retrospectively reviewing their recorded videos during their video-EEG monitoring admission and investigated the seizure variability. We extracted all the clinical data from their medical records. We also studied factors potentially associated with seizure variability.

RESULTS

Forty nine patients were studied and 220 seizures were reviewed and classified. Mean number of seizures per patient was 4.5. Twenty seven (55%) patients had subjective seizures, 26 (53%) had generalized motor, 14 (29%) had akinetic and five (10%) had focal motor seizures. Twenty eight (57%) patients had only one seizure class, while 19 (39%) patients had two different seizure classes and two (4%) patients had three seizure classes. Among 28 patients with one seizure class, 14 (50%) patients had variable semiologies from one seizure to the other. Hence, 71.5% of the patients showed either inter- or intra-class variability, whereas seizures were stereotypical in 28.5%. No demographic or clinical factors were significantly associated with variability of PNES semiology.

CONCLUSION

Neither the stereotypy nor the variability of PNES can or should be used as a marker of the disease and to differentiate PNES from epilepsy. The variability of the episodes of PNES does not hinder an appropriate classification of these seizures.