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 Attention and withdrawn appeared findings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.
