Understanding a different kind of seizure
Functional / Dissociative Seizures
These seizures are real, involuntary, and deserving of care. An accurate diagnosis helps people access treatment that addresses the condition they have.
About this information
This webpage is subject to continuous review by Epilepsy Ontario to help keep the information current. This material is for informational purposes only and should not be used for self-diagnosis or as a substitute for professional medical advice, diagnosis, or treatment. Consult your healthcare provider about your own health and care.
What are functional seizures?
Functional seizures, also called dissociative seizures, are episodes that can resemble epileptic seizures or fainting. They are associated with changes in how the brain functions, rather than the epileptic electrical activity responsible for epilepsy seizures.
You may also see the term psychogenic non-epileptic seizures (PNES) in medical records and resources.
The symptoms are not deliberate or “put on.” Functional seizures can be frightening and disabling. The outdated term “pseudoseizures” can be misleading and stigmatizing and should be avoided.
Different from epilepsy
Functional seizures and epilepsy have different mechanisms and require different treatment approaches.
Both can occur together
Some people have both functional seizures and epilepsy. Their care plan needs to explain how each type will be managed.
How is the diagnosis made?
A clinician considers the person’s history, witness descriptions, the features of the episodes, and relevant investigations. Recording a typical event during video-EEG monitoring may help establish the diagnosis.
A normal routine EEG alone does not diagnose functional seizures or rule out epilepsy. The diagnosis should be explained clearly, including which findings support it.
Do not try to diagnose someone from a single sign, such as whether their eyes are open or closed.
What can treatment involve?
Care starts with a clear explanation and a plan agreed with the person. Psychological therapies tailored to functional seizures may help reduce episodes and improve quality of life.
Support may also address other symptoms, mental health needs, and practical effects on daily activities. Stress or difficult experiences can be relevant for some people, but should not be assumed to explain every person’s symptoms.
What about anti-seizure medication?
Anti-seizure medication does not treat functional seizures themselves. It may still be needed for co-occurring epilepsy or another medical reason.
Do not stop medication on your own. Any change should be planned with the prescribing clinician.
Support without judgment
Stay calm. Protect. Follow the plan.
- Keep the surroundings safe and protect the person from injury.
- Speak calmly and give them space.
- Do not restrain them, put anything in their mouth, or use painful stimulation.
- Follow their individual response plan.
- Offer reassurance afterward and respect their privacy.
When is emergency help needed?
Call 911 for breathing difficulty, serious injury, or another medical emergency. If the diagnosis is uncertain, or the event is different from the person’s usual episodes, follow general seizure first aid and seek appropriate help.
For someone with a confirmed diagnosis, the healthcare team should provide a specific response plan. Familiar functional seizures do not always require an ambulance based on duration alone.
Questions to ask the healthcare team
- What findings support my diagnosis?
- Do I also have epilepsy or another condition?
- What should people do during an episode?
- Which treatments and local services are available?
- Who will coordinate follow-up and medication decisions?
