Repetitive and Stereotyped Behaviors in Neurodevelopmental Disorders: More than a Movement Disorder

Objectives: Stereotypies are defined as repetitive nonfunctional and purposeless motor or vocal responses that can interfere with social interactions and may result in injury. Our study aimed to systematically assess repetitive and stereotyped behaviors (RSB) among different neurodevelopmental disorders and compare them with typically developing children with primary stereotypies.

Content: Method: Study sample was composed of children aged from 2 to 12 years with current stereotyped behaviors divided in four main groups: autism spectrum disorder (ASD), developmental delay (DD), severe visual impairment/blindness (VI), and primary stereotypies (PS). The Repetitive Behavior Scale-Revised (RBS-R) to assess RSBs and the Child Behavior Checklist (CBCL) to check behavioral problems were performed by the children's caregivers. Data concerning family history and comorbidity were also collected. Characteristics of RSB (age of onset, frequency, duration, complexity, triggers, and clinical features) were collected by medical history and directly observed within 20 minutes of videotaped and semistructured play session.

Results: Eighty-seven children (ASD [n = 23], DD [n = 21], VI [n = 20], and PS [n = 23]) were assessed. On RBS-R, several repetitive behaviors, other than stereotypies, were reported by parents of all groups. Attention and withdrawn appeared findings common to all groups on the CBCL. Several comorbidities and positive family history for neurodevelopmental disorders were collected within the groups. Primary stereotypes were characterized by primarily motor and highly complex manifestations. Secondary stereotypes had higher association of motor and phonic stereotypes and different degrees of complexity. Stereotypes tend to occur many times a day (hourly in patients with severe visual impairment) in all groups, and to stop spontaneously in a short time (from seconds to few minutes). From a semeiologic point of view, stereotypes of locomotion seem to be particularly suggestive of autism spectrum disorder, as are stereotypes of the head, trunk, and eye manipulative behaviors for blindness. Stereotypes of the upper limbs, on the contrary, seem to be a more transnosographic stereotyped behavior since they are equally frequent in all groups.

Conclusion: Our results suggest that the behavioral profile of different disorders (including PS) show a significant overlap if stereotypies are present. These preliminary results suggest that stereotyped behaviors could have a sentinel role for a neurodevelopmental disorder. The characterization of stereotyped behavior, on the other hand, open the possibility of distinguishing primary from secondary stereotypies in the field of an early identification of disorders-specific findings.

Publication History

Article published online:
16 March 2022