This domain includes a number of aberrant behaviors in four different areas as follow. The diagnosis for Autism Spectrum Disorder requires these behaviors to be present in two of the four areas.
1) STEREOTYPIC MOVEMENTS, REPETITIVE OBJECT USE, OR VOCALIZATIONS/VERBALIZATIONS
These motor behaviors may include finger movements, body posturing, rocking, spinning, hand/arm flapping, full-body tensing, toe walking, or repetitive jumping. Unusual and repetitive use of objects can be seen in nonfunctional and repetitive play (eg, flipping light switches, opening/closing doors), or unusual use of toys rather than playing with them as intended (eg, lining up toys, spinning the wheels on cars). Repetitive behaviors can also be vocal, with repetitive sounds or verbal echolalia. Echolalia can be the immediate echoing of what was said around the child or delayed echoing, with scripting/reciting lines from books or videos.
2) INFLEXIBILITY, ROUTINES, AND RITUALS
These children may need to always take the same route to a given destination, eating the exact same foods or having food presented in the same way, or always having to finish what is started. Cognitive inflexibility is shown by black-and-white rigid thinking, repetitive questioning, overly strict adherence to rules, and behavioral or verbal rituals. A hallmark of children with autism spectrum disorder is that minor changes to routine, transitions, or unexpected events often elicit excessive tantrums or major changes in affect.
3) OUT OF PROPORTION INTENSE OR UNUSUAL INTERESTS
Interests can involve topics that are seemingly abnormal in focus (eg, a 5-year-old knowing everything about elevators, politics, or astrology) or excessive and persistent age-appropriate interest down to an unusual level of detail and to the exclusion of other topics or activities (eg, cars/trains or letters/numbers or animals). Children may show an unusual attachment to objects (eg, needing to carry something with them at all times) or show an atypical or intense interest in small parts of things or how things work.
4) OVERREACTIVITY OR UNDERREACTIVITY TO SENSORY STIMULATION OR UNUSUAL SENSORY BEHAVIORS
Sensory symptoms may involve any of the senses (eg, auditory, visual, tactile, or olfactory). They can be unusual sensory interests (eg, overfascination with water play), adverse responses to seemingly innocuous sounds (eg, the vacuum cleaner) or things touching the skin (eg, clothing tags), a high pain tolerance, or excessive mouthing or smelling of objects. Individuals may show fascination with lights or spinning objects. Children may demonstrate unusual visual behaviors, such as peering out of the corners of their eyes, viewing objects from unusual angles, or holding objects very close to their eyes. Some children engage in behaviors such as crashing into things, pushing their bodies into small spaces, or being calmed by tight hugs, which may represent proprioceptive sensory seeking behaviors.
REFERENCE: CONTINUUM: Lifelong Learning in Neurology: February 2018
Dr. Germano Falcao
Dr. Germano Falcao is a Mayo Clinic Trained Pediatric Neurologist who has a passion to care for children with neurological disorders and give support to their families. He is a compassionate and experienced physician, a published author, and a professor who specializes in areas involving Seizures and Epilepsy; Headaches and Migraine syndromes; Neurodevelopment Disorders; ADHD and Autism Evaluation.