ABSTRACT
To study the selectivity of visual perceptual impairment in children with early brain injury, eight visual perceptual tasks (L94), were administered to congenitally disabled children both with and without risk for cerebral visual impairment (CVI). The battery comprised six object-recognition and two visuoconstructive tasks. Seven tasks were newly designed. For these normative data are presented (age 2.75-6.50 years). Because the recognition tasks required object naming, each item included a canonical control drawing and visual perceptual ability was evaluated relative to the non-verbal intelligence level, instead of chronological age. In 22 multiple disabled children with no indications of CVI, the frequency of impairment did not exceed that in the reference sample for any L94 task. In contrast, in 57 5-year-old children who were at risk for CVI due to pre-maturity or birth asphyxia, a significant increase in the frequency of impairment was seen on six L94 tasks (range 12-38%). However, only five children had more than two impairments, indicating that the deficits were selective, not pervasive. We conclude that early brain lesions interfere with the functioning of particular visual subsystems, yet leave other subsystems intact and functioning within the normal range.
Subject(s)
Agnosia/physiopathology , Asphyxia Neonatorum/physiopathology , Birth Injuries/physiopathology , Brain/physiopathology , Hypoxia-Ischemia, Brain/physiopathology , Visual Pathways/physiopathology , Visual Perception/physiology , Agnosia/etiology , Agnosia/pathology , Asphyxia Neonatorum/pathology , Birth Injuries/pathology , Brain/pathology , Child , Child, Preschool , Developmental Disabilities/etiology , Developmental Disabilities/pathology , Developmental Disabilities/physiopathology , Female , Humans , Hypoxia-Ischemia, Brain/pathology , Infant, Newborn , Male , Neuropsychological Tests , Psychomotor Disorders/etiology , Psychomotor Disorders/pathology , Psychomotor Disorders/physiopathology , Visual Acuity/physiology , Visual Pathways/injuries , Visual Pathways/pathologyABSTRACT
Visual-perceptual abilities were assessed in 5-year-old children with the following neonatal neurological conditions: born preterm with normal ultrasound scan (NL, n=17); born preterm with ultrasound diagnosis of intraventricular haemorrhage (IVH, n=17); born preterm with ultrasound diagnosis of periventricular leukomalacia (PVL, n=12); born term with hypoxic-ischaemic encephalopathy (HIE, n=11). Visual-perceptual ability was evaluated with the L94: eight visual-perceptual tasks designed to evaluate different aspects of visual perception at the preschool level in children with multiple disabilities. Impairment was established in comparison to the performance age obtained on non-verbal intelligence subtests, instead of chronological age. Frequency of L94 impairment was highest in children with PVL, while children with IVH did not differ from the NL control group. Impairment rates were increased also in children with transient periventricular echodensities, and in children with HIE. Impairments were only moderately related to the delay of visual acuity maturation in infancy.
