Standing balance and defective sensori motor integration processes in children with neurodevelopmental disorders: the role played by hyperlaxity

Introduzione: Hyperlaxity is a common condition in general population with a prevalence of 20-30%.Hyperlaxity shows an higher prevalence in a few neurodevelopmental disorders, above all Autistic Spectrum Disorder and ADHD. Previous works reported a connection between hyperlaxity and developmental coordination disorder. Defective sensory integration could play an important role in alterations of postural control and in mantaining equilibrium. Standing balance requires the ability to integrate inputs from the somatosensory, visual and vestibular systems. It might be influenced by joint hypermobility, a condition associated with hyperlaxity, in which an excessive movement of joints I present. Previous studies have examined balance performances in children with ADHD, Autistic spectrum disorders and Tourette syndrome, finding poorer results when compared to controls. The aim of our study is to evaluate the prevalence of hyperlaxity and coordination disorders in four samples of children with neurodevelopmental disorders and to determinate whether hyperlaxity and the severity of clinical conditions are related to postural disorders. Materiali e Metodi: We recruited 86 patients belonging to three different groups according to DSM 5 diagnostic criterias (Autism Spectrum Disorder, Gilles de la Tourette syndrome, and ADHD) giving them a score for laxity (Brighton/Beighton scores, for coordination abilities (Movement ABC 2 Battery) and sensori-motor integration deficits. A sample of 24 healthy controls age-matched were evaluated using the same protocol to collect normative data. All children aged between 8 and 15. Exclusion criterias were moderate to severe intellectual disability and the presence of a neurological condition. Postural control was assessed by Computerized Dynamic Posturography performed under three conditions (eyes opened, closed, dome) on stable and compliant surface (mate). All participants were finally assessed using semistructured interview Kiddie-Sads, parents structurated questionnaries (CBCL and DCDQ) and for the autistic group ADOS evaluation. Risultati: A significant differences in all measures registered at Dynamic Posturography between ASD and other diagnostic groups were measured. Standing balance performances was poorer in autistic children than in the other groups. No significant differences were found among the other groups. A significant difference was found between children with and without joint hypermobility, showing a different and opposite trend in the SOT. The ABC Movement Coordination test showed no significant differences in performance between Tourette syndromes and ADHD. Conclusione: Co-existence of hyperlaxity and sensori-motor integration deficit may represent a clinical expression of a neuro-functional impairment that could be explained with both a disregulation of peripherical sensitive receptors and a central connective’s disorder, associated with hyperlaxity. These feautures have been reported in all three groups (ADHD, Tourette syndrome, Autistic Spectrum Disorders).We advanced the hypotesis that these patterns are associated with sensorimotor integration deficits. We advanced the hypotesis that these patterns are associated with sensorimotor integration deficits.Further analysis should be done in future on these diagnostic groups in order to report what should be the real influence of hyperlaxity in defining specific and different functional profiles in every group.