The purpose is to determine the hierarchy of sensory afferents according to different forms of dyslexia in children.

The secondary purpose is to determine sensitive and sufficiently specific posturographic indexes for standard diagnosis of different types of dyslexia.

This study evaluates the postural control and the importance of proprioception, evaluated by static and dynamic posturography, in dyslexic children compared to age-matched control group. Posturographic data and a questionnaire for motion sickness disorder are used as proprioceptive disorder index. This study aims to better characterize the dyslexic population with techniques targeting central integration of sensory proprioceptive afferents. The purpose of this study is not to search for a postural deficiency syndrome, but to study proprioception with posturography, with quantitative and normalized data of analyzed population. Moreover, these data could allow an objective evaluation of reeducation with quantifiable and reproducible parameters in order to judge its effectiveness. The demonstration of the existence of a relationship between proprioceptive disorders and dyslexia will imply a specific reeducation care of patients. A study using validated and standard indexes is necessary. The presence of postural disorders and a major susceptibility to motion sickness could contribute to distinguish different forms of dyslexia and thus be complementary to actual medical, orthophonic and neuropsychological criteria. In this evaluation, it is important to distinguish between visuo-attentional dyslexia from phonological dyslexia involving distinct anatomo-functional neuronal circuits.

Inclusion Criteria:

All:

• Parents of child and child having given informed consent
• Affiliation to social security
• Preliminary medical examination

Dyslexia groups:

- Diagnosed and characterized dyslexia

Exclusion Criteria:

All:

• Medical pathology, especially neurological, ophthalmological, otorhinolaryngological or orthopedic, modifying postural control, detected with medical examination
• Insufficient compliance of child especially due to fatigue
• Contact allergy to cutaneous electrodes
• Current treatments: psychotropic drugs and all drugs diminishing awareness or causing dizziness or equilibrium disorders

Control group:

- Patient having a dyslexia or oral or written language disorder