Aude Paquet1, Bertrand Olliac2, Bernard Golse3, Laurence Vaivre-Douret4. 1. Faculty of medicine, university of Paris Descartes, Paris, France; Inserm 1018, CESP, university Paris-Sud, UVSQ, university of Paris-Saclay, Paris, France; Department of child and adolescent psychiatry, Esquirol hospital, Limoges, France; Research and neurostimulation unit, research federation for psychiatry and innovation at Limousin, Esquirol hospital, Limoges, France. Electronic address: audepaquet@gmail.com. 2. Department of child and adolescent psychiatry, Esquirol hospital, Limoges, France; UMR 1094, university of Limoges, Limoges, France. 3. Faculty of medicine, university of Paris Descartes, Paris, France; Inserm 1018, CESP, university Paris-Sud, UVSQ, university of Paris-Saclay, Paris, France; Department of child psychiatry, Necker-Enfants-Malades university hospital, Paris, France. 4. Faculty of medicine, university of Paris Descartes, Paris, France; Inserm 1018, CESP, university Paris-Sud, UVSQ, university of Paris-Saclay, Paris, France; Department of child psychiatry, Necker-Enfants-Malades university hospital, Paris, France; Department of paediatrics, child development, Cochin-Port Royal university hospitals of Paris center, Paris, France; Endocrinology laboratory, Imagine instituts, Paris, France.
Abstract
OBJECTIVE: Motor disorders are known in autism spectrum disorder (ASD), but muscle tone assessments are rarely performed. Muscle tone underpins movement. We investigated muscle tone in 34 ASD children using a standardized neuro-developmental battery, which uses the French norms for muscular tone in children. METHODS: Dangling and extensibility were used to examine passive muscle tone in the upper and lower limbs and the body axis. A comparison between muscles of the right and left sides enabled the determination of tonic laterality. RESULTS: We found a disharmonious tonic typology, with a tonic component for the muscles of the trunk and the proximal muscles of the lower limbs and a laxity component for the ankles and the proximal and distal muscles of the upper limbs (wrists and shoulders). No establishment of tonic laterality was found in the upper limbs in 61% of ASD children (P<0.001). CONCLUSION: The disturbed tonic organization influenced by subcortical structures, such as the cerebellum, may partially explain the motor disorders, and indefinite tonic laterality may also be linked to low hemispheric brain dominance described in autism. This preliminary examination is necessary before any gross motor assessments to understand the nature of movement disorders, explore typologies and highlight possible soft neuro-motor signs.
OBJECTIVE:Motor disorders are known in autism spectrum disorder (ASD), but muscle tone assessments are rarely performed. Muscle tone underpins movement. We investigated muscle tone in 34 ASDchildren using a standardized neuro-developmental battery, which uses the French norms for muscular tone in children. METHODS: Dangling and extensibility were used to examine passive muscle tone in the upper and lower limbs and the body axis. A comparison between muscles of the right and left sides enabled the determination of tonic laterality. RESULTS: We found a disharmonious tonic typology, with a tonic component for the muscles of the trunk and the proximal muscles of the lower limbs and a laxity component for the ankles and the proximal and distal muscles of the upper limbs (wrists and shoulders). No establishment of tonic laterality was found in the upper limbs in 61% of ASDchildren (P<0.001). CONCLUSION: The disturbed tonic organization influenced by subcortical structures, such as the cerebellum, may partially explain the motor disorders, and indefinite tonic laterality may also be linked to low hemispheric brain dominance described in autism. This preliminary examination is necessary before any gross motor assessments to understand the nature of movement disorders, explore typologies and highlight possible soft neuro-motor signs.