Stereotypic Movement Disorder

What stereotypies are

A stereotypy is a repetitive, rhythmic movement that looks purposeful but has no obvious function. Typical features:

• They often start before age 3
• The pattern is fixed: the same movement each time
• They occur during excitement, stress, boredom, fatigue or when absorbed in thought, such as watching a screen
• They usually stop when the child is called or distracted
• The child may be only partly aware of them and usually is not upset by them

Stereotypies are common. Simple ones, like bedtime rocking, occur in many typically developing toddlers. "Complex motor stereotypies", like flapping the hands while running, persist in some otherwise typical children for years.

When it becomes a disorder

According to DSM-5-TR, stereotypic movement disorder is diagnosed when:

1. The repetitive, seemingly driven, purposeless movements start in the early developmental period
2. They interfere with social, school or other activities, or result in self-injury
3. They are not explained by a substance, a neurological condition, or another developmental or mental disorder such as trichotillomania or OCD

Doctors specify whether it occurs with or without self-injurious behavior, and whether it is linked to a known condition, such as autism spectrum disorder, intellectual disability, fetal alcohol exposure or Lesch-Nyhan syndrome.

Common types of stereotypies

Stereotypies vs tics

Stereotypies are often confused with tics, as in Tourette syndrome. Key differences:

They also differ from compulsions in OCD, which are performed to relieve anxiety or an intrusive thought, and from body-focused habits such as hair pulling.

Causes and risk factors

The exact cause is unknown. Stereotypies likely involve the brain circuits controlling habits and rewards (the basal ganglia and frontal cortex). They are more common in:

• Autism spectrum disorder
• Intellectual disability and developmental delays
• Blindness or deafness, where they may provide sensory input
• Genetic syndromes such as Rett syndrome, Lesch-Nyhan syndrome and fragile X syndrome
• Children who experienced severe early neglect or deprivation
• Children with ADHD, tics or anxiety

In otherwise typical children with complex stereotypies, a family history of similar movements is common.

Diagnosis

There is no test. A pediatrician, developmental pediatrician, child neurologist or psychiatrist makes the diagnosis from:

• A description of the movements and when they happen. Home videos are very helpful.
• A developmental and medical history
• Screening for autism, intellectual disability, ADHD and anxiety
• An examination to look for other neurological signs

EEG, brain imaging or genetic tests are done only if there are seizures, developmental regression or features of a specific syndrome.

Treatment

When no treatment is needed

If the movements do not cause injury or interfere with daily life, simple stereotypies need no treatment. Parents can avoid drawing attention to them or punishing the child.

Behavioral therapy

• Habit reversal training: teaches older children to notice the movement and replace it with a competing, less noticeable action, such as clasping the hands. A Johns Hopkins parent-delivered program has been shown to reduce complex stereotypies.
• Differential reinforcement: rewarding times without the behavior or alternative behaviors.
• Functional behavior assessment in children with autism or intellectual disability, to understand what triggers and maintains the behavior and change the environment accordingly.
• Occupational therapy to provide alternative sensory input.

Protecting against self-injury

Helmets, padded surfaces, gloves or arm splints may be used temporarily for severe head banging or self-biting, alongside behavioral therapy.

Medicines

Medicine is reserved for severe self-injury or when stereotypies come with significant aggression or anxiety. Options a specialist might consider include SSRIs, alpha-2 agonists such as guanfacine, and some antipsychotics. Evidence is limited.

Outlook

Simple stereotypies in typical toddlers usually fade by school age. Complex stereotypies in otherwise typical children often persist into adolescence or adulthood but frequently become less noticeable and cause little impairment. In children with autism or intellectual disability, stereotypies can be long-lasting, but behavioral support often reduces their frequency and prevents injury.

Frequently asked questions

Is hand flapping always a sign of autism?

No. Hand flapping is common in autism, but many typically developing children flap their hands when excited. It is more concerning when combined with delayed speech, limited eye contact, reduced interest in people or other social differences. A pediatrician can screen for autism.

Is head banging normal in toddlers?

Rhythmic head banging or rocking at bedtime is common in healthy toddlers and usually stops by age 3 to 4. It needs evaluation if it causes injury, happens often during the day, or occurs with developmental delays or regression.

What is the difference between a stereotypy and a tic?

Stereotypies start earlier (usually before 3), have a fixed rhythmic pattern, happen during excitement or absorption, and stop with distraction. Tics usually start around 5 to 7, change over time, are often preceded by an urge, and are brief and sudden.

Do children outgrow stereotypic movement disorder?

Many children with simple stereotypies outgrow them. Complex stereotypies often continue but usually become less noticeable with age. Children with autism or intellectual disability may need ongoing behavioral support.

How is stereotypic movement disorder treated?

Treatment is only needed if movements cause injury or interfere with life. Habit reversal training, behavioral therapy, occupational therapy and protective equipment are the main approaches. Medicine is reserved for severe self-injury.