Article

Cognitive visual dysfunctions (CVDs) reflect an impairment of the capacity
to process visual information. The question of whether CVDs might be classifiable
according to the nature and distribution of the underlying brain damage is an
intriguing one in child neuropsychology. METHOD: We studied 22 children born
preterm (12 males, 10 females; mean age at examination 8y, range 6-15y; mean
gestational age 30wks, range 28-36wks) with periventricular leukomalacia, spastic
diplegia, normal intelligence (mean Full-scale IQ 84; mean Verbal IQ 97; mean
Performance IQ 74), and normal visual acuity, focusing on higher visual
functions. Brain magnetic resonance images (MRI) were analysed to establish the
presence of lesions along the primary optic pathway, in the occipitoparietal and
occipitotemporal regions. RESULTS: Most children displayed an uneven cognitive
profile, with deficits in visual object recognition, visual imagery,
visual-spatial skills, and visual memory, and sparing of visual associative
abilities, non-verbal intelligence, and face and letter recognition. Conventional
brain MRI did not document major alterations of parietal and temporal white
matter, or cortical alteration of areas involved in visual associative functions.
INTERPRETATION: We suggest a widespread involvement of higher visual processing
systems, involving both the ventral and dorsal streams, in preterm children with
periventricular leukomalacia. The lack of major alterations on conventional MRI
does not exclude the possibility of malfunctioning of higher visual processing
systems, expressing itself through discrete CVDs. Possible mechanisms underlying
these neuropsychological deficits are discussed.

Langue : ANGLAIS