Cognitive visual dysfunctions in preterm children with periventricular leukomalacia

Abstract

Aim 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.

Thalamic changes in a preterm sample with periventricular leukomalacia: correlation with white-matter integrity and cognitive outcome at school age

“…The greater differences were found in the Processing Speed Index. As well as a measure of attention and quick scanning, the index clearly depends on visuospatial and visuoconstructive functions, reported altered in preterm children with PVL (34). It is conceivable that minor motor impairment could have affected the performance in the Perceptual Reasoning and Processing Speed indexes.…”

Definition and quantification of acute inflammatory white matter injury in the immature brain by MRI/MRS at high magnetic field

“…Quantification of astrogliosis revealed a very strong reaction in the cortex (LPS: 109654 ± 16279, NaCl: 15226 ± 9349 μm 2 ; P = 0.0002) and in the hippocampus (LPS: 425360 ± 51878, NaCl: 150354 ± 32966 μm 2 ; P = 0.0007). It also revealed a significant reaction in the cingulum (LPS: 32769 ± 7849, NaCl: 11415 ± 3421 μm 2 ; P = 0.02) and a strong reaction in the external capsule (LPS: 21505 ± 3137, NaCl: 7746 ± 1678 μm 2 ; P = 0.001).…”

“…hite matter injury in the preterm infant can lead to the most severe manifestation, namely cystic periventricular leukomalacia (PVL), with significant clinical impairment such as spastic diplegia (1), cognitive visual dysfunction (2), delayed visual maturation, strabismus, visual field defects, and attention deficit (3). Cystic PVL can be readily identified by ultrasonography, but in case of milder and more diffuse injury, the reliability of this technique comes into question (4).…”

“…Respiration rate was monitored using a custom-built pressure pillow placed under the rat's abdomen. A fast spin echo MRI sequence (repetition time = 3,500 ms, echo train length = 8, echo spacing = 13 ms, effective echo time = 78 ms) was used to obtain anatomical images with an in-plane resolution of 58 × 117 µm 2 and a slice thickness of 600 µm. Based on these images, a volume of interest (1 × 3 × 2.5 mm 3 ) for spectroscopy was centered on the corpus callosum (Figure 1a).…”

Aspects of birth history and outcome in diplegics attending specialised educational facilities

“…24 Recent studies suggest that more effort must be directed towards diagnosis and management of the visual dysfunction in survivors of PVL. 19,25 These barriers to learning require specialised teaching strategies and skills. The children in this group also demonstrated considerable limitations in mobility at school and in the community.…”