Functional (dissociative) seizures

Some people with dissociative disorders have seizures. These are often called ‘functional seizures’,  ‘dissociative seizures’ or ‘functional (dissociative) seizures’.

Unlike some types of seizures, functional (dissociative) seizures have no known physical cause. And because there's still a lot doctors don't know about seizures and dissociation, getting a diagnosis can feel confusing.

We're here to help you learn a bit more about functional (dissociative) seizures and the terms doctors use.

My non-epileptic seizures are similar to a tonic epileptic seizure. Going stiff and rigid, gasping. Combined with visual disturbances.

What are functional (dissociative) seizures?

The word ‘functional’ relates to your nervous system. It means there's a temporary change to how your brain and body communicate. It's a seizure that doctors haven't been able to find a physical cause for.

You might hear doctors calling them different names including:

• Functional seizures
• Functional (dissociative) seizures
• Dissociative seizures
• Functional non-epileptic attacks (FNEA)
• Psychogenic non-epileptic seizures (PNES)
• Non-epileptic seizures (NES)

Many of these medical names are complicated and describe what the seizures are not, rather than what they are. This isn't very helpful.

This is why people are increasingly calling them functional (dissociative) seizures. Or just functional seizures or dissociative seizures.

Although research hasn't yet found a physical cause of functional (dissociative) seizures, this doesn't mean they're not real. Or that you're acting.

What are the symptoms of functional (dissociative) seizures?

Symptoms of a functional seizure include:

• Feeling your heart beating heavily (palpitations)
• Breathing too fast (hyperventilating)
• Shaking uncontrollably in your arms, legs, head or body (convulsions)
• Dry mouth
• Sweating more than usual
• Losing control of your bladder or bowels
• Biting your tongue, especially the tip
• Going blank or staring as if you can't take anything in
• Having other symptoms that look like epilepsy

Functional (dissociative) seizures may be caused by the brain dealing with overwhelming stress by shutting down. The Epilepsy Society website has more information on functional (dissociative) seizures.

What is functional neurological disorder (FND)?

If you have functional seizures, doctors may give you a diagnosis of functional neurological disorder (FND) or non-epileptic attack disorder (NEAD).

FND is a problem with the way your nervous system works. So it affects how your brain and body communicate with each other.

You might be given one of these diagnoses if:

• You have difficulty with how your senses work, how you move or how you speak
• You can't control these symptoms
• Doctors have checked that there's no other likely cause for your symptoms - such as drugs or alcohol, medication or another mental or physical health problem
• Your symptoms feel distressing and affect your everyday life

But there isn't a clear definition. Experts disagree on whether FND is a mental health problem. Or whether there's a better way of understanding and classifying it.

When doctors classify FND as a mental health problem, they often call it ‘conversion disorder’. Or ‘dissociative neurological symptom disorder’.

There is more information about FND on the FND Action website.