Autism (ASD), attention deficit/hyperactive disorders (ADHD) and dyslexia (DYS) are defined in DSM-5 as neurodevelopment disorders (NDDs) and several times they are comorbid disorders. Several studies reported poor oculomotor performance and postural instability in this children population confirming the cerebellar deficit hypothesis in subjects with NDDs.

In this paper we summarized oculomotor and posture findings collected during the last decade in order to find out biomarkers for children with NDDs; at our knowledge, such issue has never been studied; the present study was designed to fill this gap. Oculomotor parameters (the number of express and anticipate saccades, the number of saccades during fixations and the number of catch-up saccades during pursuits) and the postural instability index measured in two viewing conditions (eyes open and eyes closed, on stable and unstable platform) were compared in four groups of 40 children. One way ANOVA reported significant difference in oculomotor parameters between the three groups of children with NDDs with respect to typically developing (TD) children group: the number of anticipatory saccades were found significantly (p < 0.001) higher in ADHD (32.4±5.9) and DYS (34.7±5.3) group; the occurrence of express saccades and catch-up saccades were significantly (p < 0.001) more frequent in ASD group (26.8±1.8 and 55.3±4.2, respectively); unwanted saccades occurred more in ADHD (8.5±0.7) and DYS (7.3±1.1) and in the fixation with distractor task they were significantly (p < 0.001) higher in ADHD group (36.3±3.9). In addition, the mixed repeated ANOVA on the postural instability index (measured under eyes open and eyes closed condition, on stable and unstable platform) reported a significant difference (p < 0.001) of such parameter in children with NDDs (ASD: 2.8±0.6; DYS: 2.6±0.5; ADHD: 2.7±0.5, respectively) with respect to the TD group (1.9±0.3); however, postural instability index failed to distinguish between the different neurodevelopmental deficits. Such abnormal oculomotor and postural performances are in line with poor cerebellar activity; oculomotor measures only could be used as phenotype biomarkers for children with NDDs. Finally, these results could be useful to clinicians in order to develop specific oculomotor and/or postural training types based on visual fixations and body stability exercises for reinforcing motor abilities in children with NDDs.