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: (LaFrance et al, 2013)

- 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%

Treatment

- Mindfulness based psychotherapy utilizing a combination of mindfulness, ACT, DBT, and CBT skills was helpful in reducing seizure frequency in a study of 26 patients (Baslet et al, 2020).

- Cognitive behavioral therapy for adults with dissociative seizures (CODES) trial, large trial involving 368 patients demonstrated no significant difference between treatment vs control group in primary outcome measure of seizure frequency, some secondary outcomes were improved in the treatment group, however, including how bothersome seizures were, and the CBT arm had longer period of dissociative seizure free period (Goldstein et al, 2020).

References

Baslet, G., Ehlert, A., Oser, M. & Dworetzky, B. A. Mindfulness-based therapy for psychogenic nonepileptic seizures. Epilepsy Behav. 103, 106534 (2020). https://pubmed.ncbi.nlm.nih.gov/31680023/

Goldstein, L. H. et al. Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragmatic, multicentre, randomised controlled trial. Lancet Psychiatry 7, 491–505 (2020). https://pubmed.ncbi.nlm.nih.gov/32445688/

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).