Vestibulo-ocular reflex function in children with high-functioning autism spectrum disorders.

Sensorimotor processing alterations are a growing focus in the assessment and treatment of Autism Spectrum Disorders (ASD). The rotational vestibulo-ocular reflex (rVOR), which functions to maintain stable vision during head movements, is a sensorimotor system that may be useful in understanding such alterations and their underlying neurobiology. In this study, we assessed post-rotary nystagmus elicited by continuous whole body rotation among children with high-functioning ASD and typically developing children. Children with ASD exhibited increased rVOR gain, the ratio of eye velocity to head velocity, indicating a possible lack of cerebellar inhibitory input to brainstem vestibular nuclei in this population. The ASD group also showed less regular or periodic horizontal eye movements as indexed by greater variance accounted for by multiple higher frequency bandwidths as well as greater entropy scores compared to typically developing children. The decreased regularity or dysrhythmia in the temporal structure of nystagmus beats in children with ASD may be due to alterations in cerebellum and brainstem circuitry. These findings could potentially serve as a model to better understand the functional effects of differences in these brain structures in ASD. Autism Res 2017, 10: 251-266. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.