Development of smooth pursuit eye movements in very preterm born infants: 3. Association with perinatal risk factors

Immature brain structures were associated with poorer eye movement performance at 8 years of age in preterm born children

AIM

Eye movements have rarely been explored in preterm born children. The aim of this study was to compare horizontal eye movements in children born preterm and full term when they reached 8 years of age.

METHODS

Eye movements were recorded in 24 preterm born children (18 boys) and 26 matched controls (19 boys), recruited by a French hospital, using an eye tracker. This identified different types of visually guided saccades, namely step, gap, overlap and antisaccades and pursuit eye movements. The saccades task measured the latency and the percentage of anticipatory and express saccades and errors. The pursuit task measured the gain and percentage of intrusive saccades.

RESULTS

This study confirmed that children born at 24-28 weeks of gestation demonstrated a global deficit in inhibitory processes compared to children born full term. The saccades were less precise in the preterm group, anticipatory and express saccades were elevated and there was a high occurrence of intrusive saccades during pursuit movements.

CONCLUSION

These findings suggest that preterm born children have immature brain structures, particularly the parietal and frontal cortexes that are responsible for both saccade and pursuit performance. These could have been the cause of the abnormal inhibitory control measured in this study.

Antenatal steroids and neurodevelopment in 12-year-old children born extremely preterm

AIM

To investigate neurodevelopmental outcome in 12-year-old children born very preterm in relation to perinatal, neonatal and socioeconomic variables. To examine whether previously described positive effects of antenatal steroids on cognition persist at 12 years.

METHODS

Prospective cohort, 78 children with gestational ages 22.7-31.9 weeks, born in 2004-2007 and examined at 12 years of age with cognitive, motor and visual motor integration tasks and compared to an age-matched control group (n = 50). Two preterm subgroups were studied: very preterm children (28-31 gestational weeks, n = 53) and extremely preterm children (22-27 gestational weeks, n = 25).

RESULTS

The preterm children had significantly lower scores on all cognitive, motor and visual motor integration tasks than the controls. Gestational age and maternal education influenced associations differently in the two preterm subgroups. Also, severe retinopathy of prematurity demonstrated strong associations to outcome. In the extremely preterm group, administration of antenatal steroids was associated with better cognition, basic attention, word generation and motor skills.

CONCLUSION

At 12 years of age, very preterm children born in the 2000s still have deficits across several neurodevelopmental domains compared to term-born peers. Administration of antenatal steroids has long-lasting associations to cognition and motor skills in extremely preterm-born children.

Reaching skills of infants born very preterm predict neurodevelopment at 2.5 years

The purpose was to investigate associations between quality of reaching for moving objects at 8 months corrected age and neurodevelopment at 2.5 years in children born very preterm (gestational age (GA), 24-31 weeks). Thirtysix infants were assessed while reaching for moving objects. The movements were recorded by a 3D motion capture system. Reaching parameters included aiming, relative length of the reach, number of movement units, proportion of bimanual coupled reaches and number of hits. Neurodevelopment was assessed at 2.5 years by the Bayley Scales of Infant Development III. There were strong associations between infant reaching kinematics and neurodevelopment of cognition and language but the patterns differed: in children born extremely preterm (GA < 28 weeks), planning and control of reaching was strongly related to outcome, while in children born very preterm (GA 28-31 weeks) number of hits and bimanual strategies were of greater relevance. In conclusion, for extremely preterm infants, basic problems on how motion information is incorporated with action planning prevail, while in very preterm infants the coordination of bimanual reaches is more at the focus. We conclude that the results reflect GA related differences in neural vulnerability and that early motor coordination deficits have a cascading effect on neurodevelopment.

Visual tracking in very preterm infants at 4 mo predicts neurodevelopment at 3 y of age

BACKGROUND

Typically developing infants track moving objects with eye and head movements in a smooth and predictive way at 4 mo of age, but this ability is delayed in very preterm infants. We hypothesized that visual tracking ability in very preterm infants predicts later neurodevelopment.

METHOD

In 67 very preterm infants (gestational age<32 wk), eye and head movements were assessed at 4 mo corrected age while the infant tracked a moving object. Gaze gain, smooth pursuit, head movements, and timing of gaze relative the object were analyzed off line. Results of the five subscales included in the Bayley Scales of Infant Development (BSID-III) at 3 y of age were evaluated in relation to the visual tracking data and to perinatal risk factors.

RESULTS

Significant correlations were obtained between gaze gain and cognition, receptive and expressive language, and fine motor function, respectively, also after controlling for gestational age, severe brain damage, retinopathy of prematurity, and bronchopulmonary dysplasia.

CONCLUSION

This is the first study demonstrating that the basic ability to visually track a moving object at 4 mo robustly predicts neurodevelopment at 3 y of age in children born very preterm.

Horizontal Tonic Conjugate Gaze Deviation in a 4-Week-Old Infant: What Can the Eyes (of the Parents) Tell?

A 4-week-old healthy infant failed to make eye contact when approached from the left. When evaluated by us at the age of 11 weeks, left tonic conjugate gaze deviation was noted. Brain MRI showed a left frontotemporal large tension arachnoid cyst causing right falcial herniation. During the insertion of an Ommaya reservoir, hemosiderin was found to be coating the inner wall of the cyst, which may indicate that the asymptomatic cyst evolved to a tension cyst due to spontaneous hemorrhage. Surgical decompression resulted in complete restoration of the horizontal gaze and considerable reduction in the size of the cyst. After 3 months a cystoperitoneal shunt was placed due to increased intracranial pressure secondary to impaired drainage of the cyst. Since then the infant has done well, with normal developmental and neurological examination during his last follow-up at the age of 5 years. Although gaze central ocular motor control is still underdeveloped and chaotic eye movements are present during early infancy, the present case report reminds us that a thorough examination of eye movements should not be overlooked during neurodevelopmental evaluation.

Impaired visual fixation at the age of 2 years in children born before the twenty-eighth week of gestation. Antecedents and correlates in the multicenter ELGAN study

BACKGROUND

Very little is known about the prevalence, antecedents, and correlates of impaired visual fixation in former very preterm newborns.

METHODS

In the multicenter ELGAN study sample of 1057 infants born before the twenty-eighth week of gestation who had a developmental assessment at 2 years corrected age, we identified 73 who were unable to follow an object across the midline. We compared them to the 984 infants who could follow an object across the midline.

RESULTS

In this sample of very preterm newborns, those who had impaired visual fixation were much more likely than those without impaired visual fixation to have been born after the shortest of gestations (odds ratio, 3.2; 99% confidence interval, 1.4-7.5) and exposed to maternal aspirin (odds ratio, 5.2; 99% confidence interval, 2.2-12). They were also more likely than their peers to have had prethreshold retinopathy of prematurity (odds ratio, 4.1; 99% confidence interval, 1.8-9.0). At age 2 years, the children with impaired fixation were more likely than others to be unable to walk (even with assistance) (odds ratio, 7.5; 99% confidence interval, 2.2-26) and have a Mental Development Index more than three standard deviations below the mean of a normative sample (odds ratio, 3.6; 99% confidence interval, 1.4-8.2).

CONCLUSION

Risk factors for brain and retinal damages, such as very low gestational age, appear to be risk factors for impaired visual fixation. This inference is further supported by the co-occurrence at age 2 years of impaired visual fixation, inability to walk, and a very low Mental Development Index.