Pediatric functional neurological disorder (FND)

What is a pediatric functional neurological disorder (FND)?

FND is a common condition that can affect multiple types of movement or sensation. It is caused by abnormalities in how the brain responds to sensory information. The brain “misfires” and sends signals to the body by mistake. These abnormalities are present at birth and do not come from or cause injury to the structure of the brain. This makes the recovery of FND better, on average, than many brain-based disorders.

FND is sometimes confused with other conditions. Doctors used to call it “conversion disorder” or “psychogenic,” but these terms are not up to date with the latest science. You may also hear people refer to “functional movement disorder” or “non-epileptic seizures.” These are subtypes of FND.

Importantly, people with FND are not “faking it.” They are not consciously controlling their symptoms or using the symptoms to get attention.

Risk factors

Among adults, FND is the second-most common reason to see a neurologist (behind headache). This is likely the same for children, but the frequency of FND among kids has not been measured as carefully. Most children start to be at-risk for FND around age 7 or 8, with the odds of developing FND going up substantially in the teen years. Children can develop FND as young as 3-4 years, but this is rare.

What are the different types of pediatric functional neurological disorders (FND)?

There are four types of FND. Each type is named for the effect it has on the body, but all are thought to come from the same brain changes. A person can have more than one type of FND at a time, and the forms they have can change over time.

1. Functional movement disorders - This is one of the most common types of FND. It affects how a child moves or walks. It can be episodic (come and go) or be constant.
2. Functional seizures (non-epileptic seizures) - This is another common type. It causes a child to have jerky, shaky episodes. Functional seizures are sometimes mistaken for epilepsy, but they have different causes. Epilepsy is caused by uncontrolled electrical signals in the brain, and functional seizures are caused by the brain handling information incorrectly.
3. Functional disorders of consciousness - This type involves blackouts (periods of unresponsiveness) or episodes of confusion.
4. Functional sensory disorders - This type may result in tingling, numbness or other unusual sensations in parts of the body. These sensations follow patterns that are different than when they have a brain or nerve injury.

How is a pediatric functional neurological disorder (FND) diagnosed?

We diagnose FND by performing a careful physical exam. The symptoms of FND may look similar to the symptoms of other brain-based conditions, such as paralysis or seizures. Your doctor will watch your child perform different movements and tasks to identify the pattern of abnormalities. The way that their movements look and change throughout the exam will usually reveal whether they have FND or a different type of disorder.

In some cases, we may do additional tests to confirm a diagnosis or look for other health conditions. 

• MRI - to help reveal issues with muscles, bones and organs
• EEG - to look for electrical issues in the brain

What causes pediatric functional neurological disorders (FND)?

FND seems to result from a combination of factors. The way a child’s brain is wired can set up the risk for FND. Then, certain experiences can “activate” that risk factor. For lots of children, that happens when they experience heightened emotions, such as nervousness or excitement.

Although emotions often play a role, we know that FND is not purely psychological. This is different from what experts used to think, when the condition was known as “conversion disorder.” That referred to people converting a highly emotional experience, like a narrowly avoided car crash, into some kind of physical symptom. But many people with FND have not had a shocking experience. So now we understand that it’s a blend of psychological and neurological symptoms.

FND is more common in people with anxiety and other mental health disorders, but it isn’t caused by those disorders. They just overlap in the same person. A child is more likely to have FND if a family member has it, because brain abnormalities are often inherited.

How are pediatric functional neurological disorders (FND) treated?

Children with FND often get better through a combination of physical therapy (PT), occupational therapy (OT) and counseling. Therapy usually involves physical tasks and exercises that help retrain a child’s brain to communicate with their body in the proper way.

Therapy can also help children identify the factors that trigger their symptoms. We may refer your child to a counselor in the community who can help with that.

A child’s condition may be tied to various factors in their lives and environment. We interview parents to get a full understanding of what may contribute to their child’s FND and how we can work together to help them get better.