Conséquences de la grande prématurité dans le domaine visuo-spatial, à l’âge de cinq ans

Visuospatial Perception in Prematurely Born Children Without Cerebral Palsy or Retinopathy but With Scholar Complaints

In the absence of any complaints in early childhood, preterm children remain more at risk of encountering academic difficulties, but their clinical picture remains not well characterized. We screened visuospatial perception in 70 children born preterm consulting for scholar complaints. Developmental Coordination Disorder (with or without comorbidities) was associated with high prevalence (27%) of impaired perception of spatial relationship. Prematurely born children who obtained no diagnosis of Neuro-Developmental Disorder exhibited a high prevalence (31%) of impaired perception of object magnitude. Regression revealed that low gestational age and fetal growth restriction significantly predicted the magnitude but not the spatial relationship perception.

Test of visuospatial construction: Validity evidence in extremely low birth weight and late preterm children at early school age

The Test of Visuospatial Construction (TVSC), a measure of visuoconstruction that does not rely on upper extremity motor response or written production, was administered to extremely low birth weight (ELBW), late preterm (LPT), and term participants at preschool (n = 355) and kindergarten (n = 265) ages. TVSC showed statistically significant weak-to-moderate positive correlations (age 3: r = .118-.303; age 6: r = .138-.348) with Developmental VMI, Differential Ability Scales-II Copying, Matrices, and Pattern Construction subtests, Baron-Hopkins Board Test, and the Purdue Pegboard. One-way ANOVA indicated ELBW performed worse than Term (p = .044) on visuospatial construction at age 3 with a small-to-medium effect size (d = -0.43). No other statistically significant differences were found at age 3 on the TVSC (ELBW/LPT: p = .608, d = -0.17; LPT/Term: p = .116, d = -0.31). At age 6, ELBW participants performed worse than LPT participants (p = .027) and Term participants (p = .012); LPT participants did not differ from Term participants. Small effect sizes at age 3 (ELBW < LPT, d = -0.17; ELBW < Term, d = -0.43) were notably larger at age 6 (ELBW < LPT, d = -0.42; ELBW < Term, d = -0.53). Important practical differences showing LPT participants performed below Term participants (d = -0.31) at age 3 were no longer evident at age 6 (d = -0.097). These findings provide preliminary evidence of TVSC validity supporting its use to detect neuropsychological impairment and to recommend appropriate interventions in young preterm children.

Cognitive outcome in childhood after unilateral perinatal brain injury

AIM

The aim of the study was to assess cognitive outcome in children with periventricular haemorrhagic infarction (PVHI) or perinatal arterial ischaemic stroke (PAIS) and relate these findings to early developmental outcome and neonatal magnetic resonance imaging findings.

METHOD

A neuropsychological assessment was performed in 50 children (26 males, 24 females) with unilateral PVHI (n=21) or PAIS (n=29) at a median age of 11 years 9 months (range 6-20y). This included tests for intelligence, verbal memory, visual-motor integration, word comprehension, attention, reaction times, and executive function. The Griffiths Mental Development Scale was used for early developmental assessment at 24 months (range 18-32mo).

RESULTS

In children with PVHI, both the early Griffiths scores (mean 87; 95% CI 83-92) and the Full-scale IQ (FSIQ) scores at school age (mean 86; 95% CI 78-94) were below the test mean of 100. In the PAIS group, early Griffiths scores were within the normal range (mean 98; 95% CI 93-104), but at school age FSIQ scores were below average (mean 87; 95% CI 80-94). In children with PVHI, FSIQ scores correlated with the level of maternal education and were lower after ventricular dilatation, whereas both involvement of the basal ganglia and thalami and development of postneonatal epilepsy were associated with lower cognitive outcome in children who had experienced PAIS.

INTERPRETATION

Cognitive outcome after PVHI or PAIS is below average, but still within 1SD for most children. Prediction of cognitive outcome remains challenging, but some early predictors can be recognized.

Selective deficit in spatial location memory in extremely low birth weight children at age six: the PETIT study

Spatial location memory has rarely been assessed in young children due to a scarcity of developmentally appropriate tests. This study sought to compare nonverbal learning and recall in children born extremely low birth weight (ELBW; <1000 g) and less than 33 gestational weeks (GW) with term-born children at early school age using a recently developed and adapted test. We administered a modification of the Hopkins Board to 210 children at age six; 84 born ELBW (35 born < 26 GW; 49 born 26-33 GW) and 126 term-born. Six measures were obtained: naming, trials-to-criterion, errors-to-criterion, delayed item recall, delayed location recall, and percent retention. After age correction, ELBW children had worse general cognition, item naming, delayed item recall, delayed location recall, and percent retention than term-born children. Delayed item recall and percent retention performances of ELBW children remained worse after correction for general cognition. ELBW groups (< 26 GW and 26-33 GW) groups performed worse than term-born children in naming and delayed item recall with chronological age as covariate. Those born before 26 GW, but not 26-33 GW, performed worse than term-born children in delayed location recall and percent retention. Differences remained significant after controlling for gender, maternal education, and delivery type. All three groups' performance declined from final learning trial to delayed location recall, with a decline greater for less than 26 GW than term-born children. Extreme prematurity (< 26 GW) and ELBW are significant risk factors for spatial location memory deficit. The modified Hopkins Board discriminated high-risk preterm and term-born children at early school age and appears to be a useful test to measure this rarely studied cognitive capacity.

Visual abilities at 6 months in preterm infants: impact of thyroid hormone deficiency and neonatal medical morbidity

BACKGROUND

Preterm infants are at risk for neonatal morbidity, transiently reduced thyroid hormone (TH) levels, and impaired visual abilities. To determine the interrelationship between these factors, we measured TH levels in the period ex utero and compared their visual abilities with those of term infants at 6 months (corrected) of age.

METHODS

The preterm group consisted of 62 infants stratified by gestational age: Group A (23-26 weeks, n = 10), Group B (27-29 weeks, n = 23), Group C (30-32 weeks, n = 19), and Group D (33-35 weeks, n = 10). Controls were 31 healthy full-term infants. In the preterm group, free thyroxine, triiodothyronine, and thyroid-stimulating hormone levels were measured at 2 and 4 weeks of life and 40 weeks postconceptional age. All infants were assessed for visual acuity, contrast sensitivity, and color vision using electrophysiological techniques.

RESULTS

Compared with controls, the preterm infants demonstrated reduced contrast sensitivity at low temporal frequencies and slower blue-yellow color processing. Groups did not differ from controls in visual acuity. In the preterm group, reduced contrast sensitivity and slow blue-yellow and red-green color vision processing were associated with low TH levels, low gestational age, and several medical morbidities.

CONCLUSIONS

Our findings signify that some of the weak visual abilities in preterm infants can be accounted for, in part, by their reduced TH levels in the early postnatal period.