Stereotyped movement disorder

Essential (Required) Features:

• Persistent (e.g., lasting several months) presence of voluntary, repetitive, stereotyped, apparently purposeless, and often rhythmic, movements (e.g., body rocking, hand flapping, head banging, eye poking, and hand biting) that are not caused by the direct physiological effects of a substance or medication (including withdrawal).
• Stereotyped movements result in significant interference with the ability to engage in normal daily activities or result in self-inflicted bodily injury severe enough to be an independent focus of clinical attention or that would result in self-injury if protective measures were not taken.
• Onset occurs during the developmental period, typically at an early age.

Specifiers related to self-injury:

A specifier should be applied with the diagnosis of Stereotyped Movement Disorder to indicate whether involves movements that result in physical harm to the individual:

6A06.0 Stereotyped Movement Disorder without self-injury

• Stereotyped movements that do not result in physical harm to the affected individual even without the presence of protective measures. These behaviours typically include body rocking, head rocking, finger-flicking mannerisms, and hand flapping.

6A06.1 Stereotyped Movement Disorder with self-injury

• Stereotyped movements that result in harm to the affected individual that is severe enough to be an independent focus of clinical attention or that would result in self-injury if protective measures (e.g., helmet to prevent head injury) were not taken. These behaviours typically include head banging, face slapping, eye poking, and biting of the hands, lips, or other body parts.

6A06.Z Stereotyped Movement Disorder, unspecified

Additional Clinical Features:

• Co-occurrence of Stereotyped Movement Disorder and Disorders of Intellectual Development is common.

Boundary with Normality (Threshold):

• Many young children show stereotyped behaviours (e.g., thumb sucking). In older children and adults, repetitive behaviours such as leg shaking, finger drumming/tapping, or self-stimulatory behaviours (e.g., masturbation) may be seen in response to boredom. These behaviours are differentiated from Stereotyped Movement Disorder because they do not result in significant interference with normal daily activities nor do they result in self-inflicted bodily injury that is severe enough to be an independent focus of clinical attention.

Course Features:

• Among typically developing children, stereotypic movements remit over time (or become suppressed). Among individuals with a Disorder of Intellectual Development and Autism Spectrum Disorder with Disorder of Intellectual Development, however, stereotyped (and self-injurious) behaviours may persist, though the presentation of these behaviours may change over time.

Developmental Presentations:

• Onset of Stereotyped Movement Disorder occurs early in the developmental period, with stereotypic movements often emerging before age three; up to 80% of children who exhibit complex motor stereotypies display them before age two.
• Stereotypic movements are common in typically developing children and often resolve with time, particularly simple stereotypic movements (such as rocking). The development of complex stereotypic movements is estimated to occur in 3 – 4% of children.
• Stereotyped Movement Disorder commonly co-occurs with Disorders of Intellectual Development and Autism Spectrum Disorder with Disorder of Intellectual Development.

Sex- and/or Gender-Related Features:

• To date, research has not systematically described differences across male and female presentations of Stereotyped Movement Disorder.
• Preschool-aged boys with Autism Spectrum Disorder with Disorder of Intellectual Development tend to have higher rates of co-occurring Stereotyped Movement Disorder.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Autism Spectrum Disorder: Repetitive and stereotyped motor movements such as whole body movements (e.g., rocking), gait atypicalities (e.g., walking on tiptoes), and unusual hand or finger movements can be a characteristic feature of Autism Spectrum Disorder but are differentiated from Stereotyped Movement Disorder by the presence of additional significant limitations in the capacity for reciprocal social interactions and social communication. Assignment of both diagnoses may be warranted if the stereotyped motor movements constitute a separate focus of clinical attention (e.g., due to self-injury).
• Boundary with Obsessive-Compulsive Disorder: In contrast to Stereotyped Movement Disorder, repetitive behaviours (i.e., compulsions) observed in Obsessive-Compulsive Disorder are typically more complex and are aimed at neutralizing unwanted intrusive thoughts (i.e., obsessions) and reducing associated negative emotions (e.g., anxiety).
• Boundary with Body-Focused Repetitive Behaviour Disorders: Body-Focused Repetitive Behaviour Disorders (i.e., Trichotillomania and Excoriation Disorder) are characterized by recurrent and habitual behaviours directed at the integument (e.g., hair and skin). In contrast, stereotyped movements in Stereotyped Movement Disorder rarely include hair-pulling or skin-picking behaviour but if they do, the behaviour tends to be composed of coordinated movements that are patterned and predictable utilizing the same muscle groups in a particular sequence to produce the behaviour. In addition, stereotyped movements are more likely to present very early in life (i.e., <2 years of age), whereas Body-focused repetitive behaviour disorders typically have an onset in later childhood or early adolescence.
• Boundary with Tourette Syndrome and other Tic Disorders: In contrast to Tic Disorders including Tourette Syndrome, stereotyped movements in Stereotyped Movement Disorder tend to be composed of coordinated movements that are patterned and predictable and can be interrupted with distraction. Stereotyped Movement Disorder is further differentiated from tics and Tourette Syndrome because the symptoms tend to emerge at a younger age, last longer than typical tics, lack a premonitory sensory urge, and may be experienced as enjoyable.
• Boundary with extrapyramidal symptoms, including tardive dyskinesia: Extrapyramidal symptoms are drug-induced movement disorders characterized by involuntary acute or tardive symptoms that are most frequently caused by antipsychotic medications. Tardive symptoms include tardive dyskinesia, which is characterized by involuntary oral or facial movements or, less commonly, irregular trunk or limb movements. A diagnosis of Stereotyped Movement Disorder is not appropriate in such cases.
• Boundary with Diseases of the Nervous System: Involuntary movements associated with Diseases of the Nervous System usually follow a typical pattern with the presence of pathognomonic signs and symptoms. If stereotyped movements are associated with Lesch-Nyhan Syndrome or another specific Disease of the Nervous System or neurodevelopmental disease, Stereotyped Movement Disorder should not be diagnosed unless the movements become a separate focus of clinical attention. In such cases, both diagnoses may be assigned.