Stereotypic Movement Disorder Fast Facts

A child with stereotypic movement disorder performs repetitive, purposeless, physical actions such as hand flapping, rocking back and forth, or headbanging.

The disorder’s behaviors usually develop before age three and may continue through childhood and adulthood.

Stereotypic movements may be associated with other conditions such as intellectual disabilities or autism, but they sometimes occur independently without apparent cause.

The disorder affects approximately 3-4% of young children.

United Brain Association

The disorder affects approximately 3-4% of young children.

What is Stereotypic Movement Disorder?

Stereotypic movement disorder (SMD) is a condition where a person (usually a child) makes repetitive, purposeless movements such as hand flapping or headbanging. The behaviors typically begin in early childhood, before the age of three, and often continue as the child gets older. SMD differs from typical repetitive movements, which are common in young children, because SMD behaviors cause the child distress or impairment.

Stereotypic movements, also called motor stereotypies, are often associated with other conditions, such as intellectual impairments or autism spectrum disorder. However, the movement behaviors sometimes occur by themselves without the presence of another disorder. These isolated behaviors are called primary motor stereotypies. Repetitive behaviors associated with other conditions are called secondary motor stereotypies.

Symptoms of Stereotypic Movement Disorder

Stereotypic movements can be categorized according to their complexity and persistence. “Common” motor stereotypies include relatively simple movements that often become less frequent with age. “Complex” stereotypies include more complicated, pronounced behaviors.

Common stereotypic behaviors include:

  • Thumb sucking
  • Nail-biting
  • Hair twisting
  • Teeth grinding
  • Jaw clenching
  • Body rocking
  • Self-biting
  • Headbanging

Complex stereotypic behaviors include:

  • Hand or arm flapping
  • Hand waving or twisting
  • Wiggling fingers in front of the face

What Causes Stereotypic Movement Disorder?

The cause of stereotypies is unknown, but many different factors appear to increase the risk of developing stereotypic movement behaviors. Some of the factors impact young children during their early development. Others are neurological or mental health-related issues that are sometimes associated with stereotypies. Still others are external factors that sometimes trigger repetitive behaviors or make them worse.

Possible risk factors for stereotypies include:

  • Stress, frustration, or boredom
  • Social isolation
  • Autism
  • Intellectual disabilities
  • Head injuries
  • Use of certain drugs (e.g., cocaine, amphetamines)

Is Stereotypic Movement Disorder Hereditary?

In many cases, stereotypic movement disorder is probably caused by external factors, neurological disorders, or other underlying conditions other than genetics. However, studies have suggested that some people have a genetic predisposition to developing repetitive behaviors, and that predisposition may be inherited. Despite evidence that there is a connection between stereotypies and genetics, researchers have not yet identified any gene or genes associated with the disorder.

How Is Stereotypic Movement Disorder Detected?

Stereotypies typically develop in early childhood and may be challenging to differentiate from normal developmental behavior. It is not unusual for children to exhibit repetitive behaviors, but typical repetitive behaviors do not interfere with their ability to function or cause significant distress. In addition, typical repetitive behaviors generally fade over time, while stereotypies usually persist through childhood and adulthood.

If your child makes persistent, repetitive movements and shows no signs of other developmental disorders, you should consult your doctor.

How Is Stereotypic Movement Disorder Diagnosed?

Doctors may take several different diagnostic steps when a patient is experiencing stereotypies.

  • Physical exam. A basic physical exam will screen for indications of medical conditions that could be causing the stereotypic behaviors.
  • Laboratory tests. The doctor may order laboratory blood tests to rule out conditions that could be causing the stereotypies.
  • Imaging exams. Imaging exams such as magnetic resonance imaging (MRI) or computerized tomography (CT) may be recommended if your doctor suspects a neurological cause of the symptoms.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) includes diagnostic criteria providers can use to stereotypic movement disorder. This diagnosis is possible if there is no other medical, neurological, developmental, substance-induced, or mental health-related cause of the behavior.

The DSM criteria include:

  • The patient engages in repetitive, purposeless behavior.
  • The symptoms have lasted at least four weeks.
  • The symptoms cause significant impairment or distress.
  • The symptoms are not caused by a mental disorder, a medical condition, medications, or substance use.


How Is Stereotypic Movement Disorder Treated?

Treatment for stereotypic movement disorder usually involves behavioral therapy to help people with the disorder learn to control their habitual movements. So far, no medication has proven effective in treating stereotypies.

How Does Stereotypic Movement Disorder Progress?

Sometimes stereotypic behaviors diminish or resolve over time, but often the behaviors continue beyond childhood. Complex stereotypies may be less likely to improve than common stereotypies, and stereotypies associated with intellectual disabilities and autism are more likely to persist into adulthood.

Possible long-term complications of stereotypies include:

  • Problems at work or school
  • Relationship difficulties
  • Anxiety or depression
  • Self-injury

How Is Stereotypic Movement Disorder Prevented?

There is no known way to prevent stereotypic movement disorder, but early intervention and treatment may improve symptoms and prevent significant long-term impairments.

Stereotypic Movement Disorder Caregiver Tips

Many people with stereotypies also suffer from other brain and mental health-related issues, a condition called co-morbidity. Here are a few of the disorders commonly associated with stereotypies:

Stereotypic Movement Disorder Brain Science

Recent research has suggested that stereotypies might be associated with problems related to a brain chemical called gamma-aminobutyric acid (GABA). GABA is a neurotransmitter, a chemical that allows nerve cells to communicate with each other and other types of cells. One study found that children with complex motor stereotypies had lower levels of GABA in their anterior cingulate cortex and striatum, parts of the brain associated with functions that include social behavior and impulse control.

GABA is the primary inhibitory neurotransmitter in the brain. One of its jobs is to counter the action of glutamate, an excitatory neurotransmitter. Glutamate allows the transmission of electrical signals from one brain cell to another, and GABA helps inhibit signals when the transmission is inappropriate. Glutamate and GABA work together to keep the brain functioning properly.

If GABA levels are inadequate in the parts of the brain responsible for social behavior and impulse control, nerve signals could propagate uncontrollably. Consequently, those uncontrolled signals might lead to the characteristic behaviors of motor stereotypies.

Stereotypic Movement Disorder Research

Title: Cerebral Activity Related to Primary Motor Stereotypies in Children: An EEG Study

Stage: Completed

Principal investigator: Beth A. Belluscio, MD

National Institute of Neurological Disorders and Stroke

Bethesda, MD

Objective: Motor stereotypy is a common movement disorder observed in children and adolescents but whose pathophysiology is unknown. Therefore, our overall objective is to study cerebral activity related to stereotypies. First, we want to define whether motor stereotypies are preceded by a cortical potential, as it is observed before voluntary movements. We hypothesize that no pre-movement potentials will precede the stereotypies. However, if a pre-movement potential is observed, our secondary objective is to compare this potential to cortical potentials that precede voluntary movements. We also aim to study cortical potentials preceding voluntary movements in healthy children and to compare them with the potentials observed in children with stereotypies.

Study population: 12 children presenting with primary motor stereotypies and 12 healthy children.

Design: Using 19 scalp electrodes, we will record the patient’s electroencephalographic (EEG) activity for up to 8 hours during one day. The electromyographic (EMG) activity of the muscles involved in the stereotypies will be recorded with surface EMG electrodes. Healthy children will undergo an EEG for 2 hours. During this EEG recording, they will be asked to perform arms movements.

Outcome measures: Primary outcomes: latency and amplitude of both evoked and induced activity (cortical potentials) related to motor stereotypies will be measured.

Secondary outcomes: latency and amplitude of evoked and induced activity related to voluntary movements will be measured.


Title: Use of Functional Behavioral Assessments to Evaluate Stereotypy and Repetitive Behaviors in a Double-blind, Placebo-Controlled Trials of Various Medications Used to Treat Children With Autism

Stage: Completed

Principal investigator: Latha Soorya

Icahn School of Medicine at Mount Sinai

New York, NY

Autism, originally described by Kanner (1943), is among the most severe neuropsychiatric disorders. It is a pervasive developmental disorder affecting social, communicative, and compulsive/repetitive behaviors characterized by stereotypic complex hand and body movements, craving for sameness, and narrow, repetitive interests. Individuals with autism spectrum disorders (ASD) are characteristically heterogeneous and show marked variability in their response to interventions. Studies of behavioral and psychopharmacological interventions document approximately 1/3 of ASD participants fail to respond to targeted treatments. Efforts to evaluate the specificity of treatment effects are important to inform conceptualizations about the disorder, identify behavioral phenotypes, and aid clinical decision-making.

This study aims to evaluate the use of clinical behavioral pharmacology methods, functional behavioral assessments (FBA), in assessing the treatment effects of pediatric medications in children with ASD. The present study of FBA procedures in pharmacological treatment will be conducted as a separate but parallel study within IRB approved, federally funded, double-masked, placebo-controlled medication trials of citalopram (GCO # 01-1295 PS*), an SSRI hypothesized to reduce stereotyped and repetitive behaviors in ASD and divalproex sodium (GCO # 01-0294), a medication recently found to reduce repetitive behaviors in ASD (Hollander et al., in press). This study will focus on the use of FBAs in distinguishing responders vs. non-responders on the basis of behavior function, in evaluating functional patterns for stereotypy, aggression, and impulsivity, and in using descriptive FBAs as outcome measures in clinical trials.

FBAs are behavioral assessment methods used to hypothesize about the function of maladaptive behaviors. FBAs are conducted either through experimental manipulations known as functional analyses or through descriptive analyses procedures, which involve structured observations and parent/caregiver interviews. Descriptive analyses will be conducted with all participants (n=24). The more rigorous, functional analyses will be conducted with a subset of the sample (n=6) to corroborate the findings of the descriptive analyses. Data from the FBAs will be collected using videotaped recordings of behavior and coded by trained raters for both the descriptive and experimental analyses.

Our pilot data and other published data suggest that certain medications such as citalopram (Celexa) and divalproex sodium (Depakote) may improve global functioning in autistic patients and repetitive/compulsive behaviors and social deficits. The addition of FBA methods to evaluate outcomes is an important step in extending the research and knowledge of the conditions associated with good and poor treatment response to pediatric medications in children with autism.


Title: Citalopram for Children With Autism and Repetitive Behavior (STAART Study 1)

Stage: Completed

Principal investigator: Bryan King, MD

University of Washington

Seattle, WA

For children with autism spectrum disorders (ASD, also known as Pervasive Developmental Disorders – PDDs), repetitive behaviors are common and frequently interfere with functioning in the home and social and educational settings. These behaviors may involve repetitive movements, rigid routines, repetitive play, and even repetitive speech. These behaviors may be associated with high levels of anxiety and severe tantrums. Self-injury can occur when these behaviors and routines are interrupted.

Participants will be randomly assigned to receive citalopram or placebo (administered as liquid) and carefully followed every two weeks. At the end of 12 weeks, children who have responded to treatment will be given the opportunity to continue in the study, with monthly visits, for an additional 24 weeks. Children who received a placebo and did not respond to treatment at 12 weeks will be given the opportunity to receive a carefully monitored 12-week course of citalopram.

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