SUMMARY
In functional movement disorder (FMD), a child has abnormal, involuntary body movements. FMD movements are not caused by something physically wrong with a patient’s brain, spinal cord, or muscles. There may or may not be a psychological cause present. FMD is also known as psychogenic movement disorder and falls under the umbrella of “functional neurological disorders.”
There are three common abnormal movements that appear in FMD. The first is tremor, or shaking. The second is dystonia. Dystonia appears as spasms, abnormal posture, or twisting of arms and legs, torso, head, or combination of different body parts. The third is myoclonus. Myoclonus appears as jerky limb or trunk movements. FMD can also include tics, speech problems, and more.
Physical exams, neuroimaging, and laboratory data usually do not explain FMD symptoms. The cause of the movements is not clear. Sometimes, they seem to be a reaction to stress. However, stressful events do not need to be present for a child to have FMD.
Several features can point to a FMD diagnosis.
Three are the most common:
- An abrupt onset of symptoms
- Symptoms that disappear when the patient is distracted
- A combination of several symptoms not typically seen together when symptoms come from a physical cause
SIGNS AND SYMPTOMS
Diagnosing Functional Movement Disorder
FMD is diagnosed by the presence of several features. These features might be noted in a patient’s story or in a physical exam.
They include:
Rapid progression
Episodic history
Unusual movement patterns
Symptoms of Functional Movement Disorder
The physical symptoms of FMD consist of abnormal body movements. A variety of movements are common in FMD.
These include:
Dystonia
Tics
Difficulty speaking
Inconsistent stuttering or speech difficulties. Usually if a person has difficulty speaking from a physical cause, the speech issues do not change over a short amount of time. These changes in speech may last for short periods of time and patterns may change quickly. It is important to note that some neurologic conditions, including transient ischemic attacks (TIAs) which is a precursor to stroke, may also present with intermittent speech difficulties; these difficulties are more commonly slurred speech and often associated with weakness on one side of the body.
CAUSES
The causes of FMD movements are poorly understood. However, they may be triggered by stressors. These stressors can be physical or psychological in nature.
Stressors may include:
- Physical injury
- Infection
- Surgery
- Depression or anxiety in a child or parent
- School-related problems, such as bullying or missing school
- Parental conflict (parents fighting, divorce, etc.)
- Domestic violence
- Sexual abuse
- Death of a loved one
- Participation in competitive sports or dance
Something stressful to the patient may not seem significant to others. The family or doctor may not think the stressor is significant. In some cases, no significant stressor is identified at all.
It is hard to say why FMD occurs in some children and not others.
TREATMENT AND THERAPIES
The goal of treatment is to restore normal movement and function. Identifying a stressor can be helpful. Developing skills to cope with stress can be helpful, too. Therapy may be needed to treat FMD.
Treating FMD is multidisciplinary and may involve:
- Neurologists
- Psychiatrists
- Psychologists
- Physical therapists
- Occupational therapists
- Speech-language pathologists
There is usually no medication used to treat FMD movements. However, there are exceptions. Sometimes a patient suffers from another mental health disorder. Anxiety and depression are common examples. These disorders can contribute to FMD. When they do, a patient may be offered medication. Families and treatment teams usually discuss medication decisions together.
When a patient is diagnosed with FMD, it is very important that their support system agrees with the diagnosis and therapies. This support system may include parents, guardians, siblings, and friends.
The duration of a FMD treatment is different from patient to patient. It often depends on how the patient responds to the treatment.
OUTLOOK
What Is the Prognosis of Functional Movement Disorder?
The prognosis of FMD is generally good with treatment. Still, the success of treatment varies. It is more successful when the time between when symptom onset and treatment is shorter.
Features that signal a better prognosis:
- Onset in childhood
- Earlier diagnosis
- Depression or anxiety also diagnosed
- Stressors are eliminated
Features that signal a worse prognosis:
- Onset at older age
- Delayed diagnosis
- Longer duration of symptoms
Children with FMD typically lead normal lives as older children and adults. It is possible to cure this disorder.
Resources
ORGANIZATIONS/GROUPS
Functional Neurological Disorder
The Functional Neurological Disorder private Facebook group is an international group whose mission is to help patients with functional neurological disorder (FND) get support. The group of almost 10,000 includes family members and caregivers. They host support subgroups for professionals, caregivers, the USA, and Canada who are living with FND. Since children are increasingly being diagnosed with this disorder, parents/guardian/caregiver are encouraged to join the private online communities.
Functional Neurological Disorder (FND) — A Patient’s Guide to FND
The Functional Neurological Disorder (FND) — A Patient’s Guide to FND, is a self-help website for patients with FND. The website, originally created in 2009 by Professor Jon Stone, a neurologist with a special interest in these problems, aims to give a better understanding of these symptoms. The updated, comprehensive website includes a list of symptoms, causes, treatment, videos, and fact sheets for FND.
PUBLICATIONS
JCN: Functional Neurological Disorders
Podcast from SAGE Neuroscience and Neurology/Journal of Child Neurology (JCN). Dr. Christy talks with Dara Albert, DO, pediatric epileptologist, associate professor and medical director of the multi-disciplinary Psychogenic Non-epileptic Events Clinic at Nationwide Children’s Hospital talks about the presentation, work-up, diagnosis and treatment of functional neurological disorders.
Child Neurology Foundation (CNF) solicits resources from the community to be included on this webpage through an application process. CNF reserves the right to remove entities at any time if information is deemed inappropriate or inconsistent with the mission, vision, and values of CNF.
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