PNES, Functional Seizures, and Other Imitators

By Dovy Paukstys, Founder, Komori Care

This article is educational and is not medical advice. It does not diagnose, treat, prevent, or cure any condition. Komori is not a medical device, is not FDA-cleared, does not detect seizures, and is not intended for people with epilepsy. Talk with a neurologist or epileptologist about personal medical decisions. Households living with epilepsy should use clinically validated seizure-detection devices as directed by their care team.

Some events look exactly like a seizure and are not epilepsy. That sentence is easy to say badly.

People hear "nonepileptic" and translate it to "fake." That translation is wrong. The events are real. The person is not performing. The brain is not doing the electrical storm that defines an epileptic seizure.

I am not a clinician. I do not diagnose this. I am mapping the words so a searcher does not walk into a clinic already armed with the wrong story.

The names keep changing. The events do not.

NINDS uses "nonepileptic events" and "psychogenic nonepileptic seizures" (PNES). Outwardly they resemble epileptic seizures. They are not tied to the electrical discharge that defines an epileptic seizure.

An ILAE task force has proposed a newer label: functional/dissociative seizures (FDS). The older term, PNES, dominated papers in the 2000s. Patients and clinicians both complained about it. "Psychogenic" sounded like a dismissal. "Nonepileptic" defined the event by what it is not.

You will still see PNES on charts and in older papers. You will see FND, conversion disorder, dissociative seizures, functional seizures. Same neighborhood. A neurologist picks the language they use with you. A blog does not.

Perez and LaFrance, in a 2016 review I opened on PMC, put PNES inside functional neurological disorder. Paroxysmal events that resemble epileptic seizures but are not associated with pathological changes in cortical activity.

Diagnosis is clinical. Full stop.

You cannot sort this from a video on a phone. You cannot sort it from a wearable. Tongue biting and incontinence do not settle it. The Perez/LaFrance review is explicit: those signs do not reliably separate PNES from epileptic seizures.

The gold standard is video-EEG. Record a typical event. See the behavior. See the EEG at the same time. No epileptiform activity in the peri-ictal window, plus a history and semiology that fit PNES. That is a documented diagnosis.

ILAE's 2013 Nonepileptic Seizures Task Force built a staged certainty scale because video-EEG is not available everywhere, and some people seize too rarely to catch an event in a hospital week.

• Possible: history fits, event described, interictal EEG without epileptiform activity.
• Probable: a clinician reviewed video or saw it, plus that EEG.
• Clinically established: an experienced clinician saw typical semiology, and EEG around a captured event is without epileptiform activity.
• Documented: typical event on video-EEG, no epileptiform activity immediately before, during, or after.

A normal routine EEG does not prove PNES. A single spike does not prove epilepsy. People can have both. The review cites coincidence of PNES with epileptic seizures at about 10 percent. Different events in the same person get classified separately.

Only a clinician who does this work should move someone up that scale.

Other imitators

PNES is not the only thing that looks like a seizure.

NINDS lists narcolepsy, Tourette syndrome, cardiac arrhythmia, and other medical conditions whose symptoms get mistaken for epilepsy. Syncope (fainting) is the other big adult imitator. Migraine, parasomnias, TIAs, and paroxysmal movement disorders show up in the differential. In kids the list is longer and includes behavioral states that are not seizures at all.

Frontal lobe epileptic seizures can look "weird" and get mislabeled as nonepileptic. The reverse happens too. This is why "it looked like X, so it is X" is a bad rule.

Febrile seizures in children, first provoked seizures, and eclampsia are other NINDS examples of events that involve seizures or seizure-like episodes and may not be epilepsy.

If the question is "was that a seizure," the answer lives in a neurology clinic, often with EEG, sometimes with video-EEG, sometimes with a cardiology workup. Not in a comments section.

What this is not

It is not a character judgment.

It is not "all in the head" as a way to end the conversation. Functional neurological disorders sit at the boundary of neurology and psychiatry. That is a location, not an insult.

It is not something antiseizure medicine is expected to stop. NINDS says PNES do not respond to antiseizure drugs. Treatment, when it is offered, is often a form of cognitive behavioral therapy aimed at the events. That is a clinician call. I am not ranking therapies.

It is not rare in epilepsy clinics. People get referred for "seizures" and leave with a different diagnosis. The delay is common. The cost of the delay is real: wrong drugs, missed treatment, more ER visits. The Perez/LaFrance review walks through that utilization problem. I am not repeating their hospital-day counts here. The point is the delay, not the spreadsheet.

How to use this page

If events are happening and nobody has captured one on EEG, ask the neurologist whether video-EEG is on the table. Ask whether more than one event type is in play. Ask who else should be on the team if the diagnosis is PNES or FDS.

If someone already has an epilepsy diagnosis and new events look different, say so. Mixed pictures exist.

Do not drop prescribed antiseizure medicine because a blog mentioned PNES. Stopping medicine the wrong way can land a person in status epilepticus.

Consumer gadgets do not make this diagnosis. Komori does not. A watch does not. A bedroom camera does not. Households living with epilepsy still use clinically validated seizure-detection devices as their care team directs. That is a different problem from "is this even epilepsy."

Related reading

• Epilepsy: A Plain-English Guide
• What is epilepsy vs a seizure
• How epilepsy is diagnosed
• Types of seizures

FAQ

Are PNES "fake" seizures?

No. The events are involuntary. They are not the electrical events that define epileptic seizures. NINDS and the ILAE task force treat them as a real diagnosis, not a performance.

Can someone have epilepsy and PNES?

Yes. The Perez/LaFrance review cites coincidence at about 10 percent. Each event type still needs its own workup.

What is the test that settles it?

Video-EEG of a typical event, read with the history, is the gold standard in the ILAE staged approach. Access is uneven. Lower certainty levels exist when video-EEG is not possible.

Should I stop antiseizure medicine if I think this is PNES?

Not on your own. Withdrawal, when it happens, is a clinician decision after the diagnosis is actually made. Stopping the wrong way is dangerous.

Sources

• NINDS, Epilepsy and Seizures (nonepileptic seizures section): https://www.ninds.nih.gov/health-information/disorders/epilepsy-and-seizures
• Perez and LaFrance, Nonepileptic Seizures: An Updated Review, PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC5438261/
• LaFrance et al., Minimum requirements for the diagnosis of psychogenic nonepileptic seizures, Epilepsia (2013): https://onlinelibrary.wiley.com/doi/10.1111/epi.12356
• ILAE task force proposal on functional/dissociative seizures (White Rose record): https://eprints.whiterose.ac.uk/id/eprint/231023/