Psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) has gone by many names, including dissociative seizures, hysterical seizures, pseudoseizures, nonepileptic attacks, et cetera.

Diagnosis: the gold standard for diagnosis of PNES is video EEG monitoring demonstrating a typical clinical event in the absence of epileptiform correlate

Levels of diagnostic certainty (LaFrance et al, 2013)

- Possible: the episode includes characteristics consistent with PNES self-described by patient or a witness. There is no epileptiform activity on routine or sleep deprived EEG.

- Probable: the episode includes characteristics consistent with PNES as witnessed by a physician. There is no epileptiform activity on routine or sleep deprived EEG.

- Clinically established: the episode includes characteristics consistent with PNES as witnessed by a physician familiar with epilepsy or PNES. There is no epileptiform activity on routine or sleep deprived EEG when the patient experiences a typical event.

- Documented: the episode includes characteristics consistent with PNES as witnessed by a physician familiar with epilepsy or PNES during video EEG. There is no epileptiform activity on video EEG when the patient experiences a typical event.

Signs favoring PNES:

- Long duration (convulsive episodes with motor features lasting longer than 2 minutes raises suspicion for PNES, longer than 10 minutes strongly suggests PNES)

- Fluctuating course, specificity 96%

- Asynchronous movements (may also occur in frontal lobe partial seizures), specificity 93-100%

- Pelvic thrusting (may also occur in frontal lobe partial seizures in which semiology includes short duration, tonic posturing, and occurrence from sleep), specificity 92-100%

- Side to side head and/or body movement (convulsive events only), specificity 92-100%

- Eyes closed, specificity 74-100%

- Ictal crying, specificity 100%

- Memory recall, specificity 90-96%

Signs favoring epilepsy

- Occurrence from EEG-confirmed sleep, specificity 100%

- Postictal confusion, specificity 84-88%

- Stertorous breathing (convulsive events only), specificity 100%

References

LaFrance, W. C., Baker, G. A., Duncan, R., Goldstein, L. H. & Reuber, M. Minimum requirements for the diagnosis of psychogenic nonepileptic seizures: A staged approach: A report from the International League Against Epilepsy Nonepileptic Seizures Task Force. Epilepsia 54, 2005–2018 (2013).