What is Functional Motor Disorder?

Functional motor disorder, or FMD for short, is a common diagnosis made by neurologists. People with FMD can experience a range of different symptoms including:

  • weakness or paralysis

  • shaking or tremor

  • abnormal movements of the arms, legs, body or head

  • difficulty walking normally

  • loss of sensation or numbness

 

These symptoms relate to a disturbance in normal motor control and sensory perception, or in other words, there is a problem with the way the brain is communicating with the body. The symptoms of FMD are not caused by disease, damage or structural changes to brain and body. However, this does not necessarily mean the symptoms are any less distressing and disabling.

What Causes FMD?

Like most things to do with the brain we do not fully understand the cause of FMD, however, we are learning more and more every year. Here are some things we do know about FMD:

FMD is multifactorial: There is probably no single cause to FMD. It is more likely that a number of different factors all together result in an individual developing FMD.

Everyone is different: Lots of different factors can lead to someone developing FMD and different factors will be relevant for different people.

Triggering events: Some people with FMD, but not everybody, can identify an event that seemed to trigger their problem. Some common triggers include injury, illness, surgery and a panic attack.

The brain's spotlight: The symptoms of FMD are made worse when the person's attention (the spotlight of their brain) is directed towards their body.

Symptoms can improve: Sometimes improvement happens spontaneously without treatment. It is also true that some people with FMD do not improve even after having good treatment.

Brain or Mind?

There is a long running discussion about whether FMD is a problem with the brain or the mind, in other words, is the problem biological or psychological? This is not a very helpful way to think about FMD for a number of reasons:

  • Psychological problems can have a biological basis.

  • Biological problems will have a psychological impact.

  • FMD is multifactorial, so for some people, psychological problems will be one of the factors contributing to their movement problem. For other people psychological problems will be less relevant.

  • Whichever way you think of it, it is all happening in the brain! The distinction between the mind and the brain is not one that is supported by modern neuroscience.

It is probably better to think about FMD as a brain problem. For some people psychological factors are an important part of the cause and treatment. For other people, psychological factors may not be relevant in this way. Everybody is different.

Treatment for FMD

The diagnosis of FMD is usually made by a neurologist. Sometimes a person with FMD may be referred to see a psychiatrist or neuropsychiatist. Other health professionals that are most commonly involved in helping people with FMD include: