Les pathologies neurovisuelles chez les enfants cérébrolésés

Cerebral visual impairment is one of the main causes of child visual impairment in developed countries. The pattern of the brain damage is dependent on the stage on brain development at insult, the severity and the duration of the insult. Brain pathology caused by an insult during the first and second trimester will cause cerebral malformations. Between 24 and 34 weeks, brain damage is referred to as periventricular leucomalacia, subcortical damage affecting particularly visual pathways. After 34 weeks, hypoxic-ischaemic injury leads to cortical lesions in chronic injury and subcortical nuclei lesions in acute hypoxia. Visual dysfunction is caracterized by fixation troubles, subnormal acuity, visual fields defects, difficulty with perceiving depth, cognitive defects (dysgnosia [pictures, objects], prosopagnosia, visuospatial disorders, clumsiness to identify an element within a crowded scene and to bring about visually guided movement, difficulty with movement perception), ocular motility disorders (tonic gaze deviation, strabismus, nystagmus).