Stereotypies in Autism: The Construction of a Large VIDEO Catalogue from a Cohort Study

Background:

Stereotypies, despite their high frequency and strong diagnostic significance within autism, have not yet been fully elucidated due to their broad spectrum of presentation and pattern complexity. Standardized video-recordings can help to depict the complex pattern of stereotypies commonly observed in autism, thus allowing for a better definition of major phenotypes.

Objectives:

The aim of this study is to analyze stereotypies patterns observed in a sample of children and adolescents residing at our Institute and subsequently classify them by means of video-recordings.

Methods:

20 expert caregiver wearing a body cam recorded specific stereotypic behavior in a natural context during the everyday activities of 67 autistic subjects for 3 months of close follow-up. After a few minutes of recording, the possibility to interrupt their behavior by intervening physically to divert attention was registered.

A team consisting of a senior child neuro-psychiatrist and a senior psychologist reviewed all the video recordings (1868) selecting 780 of them as the most meaningful to summarize the whole spectrum in each individual in the given time window. Each video was classified according to components (motor, sensorial, vocal, intellective), complexity (2 classes, simple and complex), body parts involved (n=18) and sensory channels involved (hearing, sight, proprioception, taste, pain, smell).

Results:

The vast majority ( 87%) of the780 patterns occurred several times generally (73%) in a state of tranquility.

In more than half of cases (53.4%), the interruption required intervening physically, but a poor correlation was found between the pattern type and possibility to interrupt the behavior by way of verbal or physical intervention ( r= -0.08/+0.08).

The individual stereotypies spectrum ranged from 1 to 33 different patterns (average= 11.6; S.D= 6.82). The most frequent pattern was represented by the combination of simple motor and sensorial components ( accounting for 23% of the total number) followed by simple motor and simple sensorial (9% and 8% respectively). The other 47 patterns with combinations from 1 to 4 components accounted for the remaining 60%.

In the 569 patterns containing motor components, whole body and arms movements constituted the most frequent body parts involved (41% e 38% respectively) followed by mouth and hands (10% and 9.8% respectively).

In the 531 patterns containing sensorial components, the most frequent channel involved was tactile (50%) followed by proprioceptive( 34%) and acoustic (19.5%).

Most of the 127 stereotypies with vocal components were constituted by simple vocalizations, 85.8% and only 14.2% by phonemes or words.

Conclusions:

This study represents a first attempt to systematically document the patterns of expression of stereotyped behavior in a cohort of autistic subjects closely followed by professional educators.

Open access to this video bank and to the clinical data will be allowed to interested researchers , with the aim of improving the comprehension of this complex phenomenon and its correlation with clinical and demographic features.