Reader variability in the use of diagnostic terms to describe white matter lesions seen on cranial scans of severely premature infants: the ELGAN study

On punctate white matter lesions in preterm infants: Is ultrasound diagnosis feasible?

OBJECTIVES

To observe hyperechoic nodular or punctate white matter lesions (HNPL) in a population of preterm infants using routine cranial ultrasound (cUS), to describe the characteristics of HNPL, and to compare them with punctate white matter lesions (PWML) detected in magnetic resonance imaging (MRI).

DESIGN

Retrospective observational single-center cohort study.

SETTING

Level 2B neonatal unit in France.

PATIENTS

307 infants born <33 weeks gestation undergoing routine cUS with a total of 961 cUS performed.

MAIN OUTCOME MEASURES

Description of lesions (HNPL/PWML): presence or absence, number, size, location, and structural distribution.

RESULTS

Among the 307 included infants, 63 (20.5%) had at least one cerebral lesion, with 453 HNPL for 63 infants. HNPL were numerous (more than three in 66.6% of cases), primarily grouped in clusters (76.2%), located near the lateral ventricles (96.8%), and measuring more than 2 mm (79%). HNPL were diagnosed on day 29 on average and persisted until term. Overall, 43 MRI were performed in 307 infants, on average 18.9 days after last cUS, in 21 of those the indication was presence of HPNL on cUS. Of these 21 MRI, 14/21 presented 118 PWML compared to 173 HNPL on cUS. In the remaining MRI (7/21), no PWML were detected compared to 47 HNPL on cUS.

CONCLUSIONS

In our population of 307 preterm infants, cUS allowed the diagnosis of HNPL, with a large similarity to PWML in MRI and a better sensitivity. But in the absence of data on inter-observer variability, we cannot exclude overdiagnosis of HNPL.

Thyroid hormone supplementation in preterm infants born before 28 weeks gestational age and neurodevelopmental outcome at age 36 months

BACKGROUND

Thyroid hormones are required for normal brain maturation, and neonatal plasma thyroid hormone concentrations are low in infants less than 28 weeks gestation. It is not known whether treatment of such infants with thyroid hormone improves neurodevelopmental outcome.

METHODS

At three years corrected age, mental, motor, and neurological development was assessed in infants born at less than 28 weeks gestational age who had participated in a phase 1 trial of differing doses and modes of administration of thyroid hormone. The trial's endpoints were thyroid hormone (thyroxine, T4) and thyotropin plasma concentrations in eight study arms: six treated with T4 [4, 8, and 16 μg/(kg · day)], bolus or continuous], one treated with iodine only, and one treated with placebo. Follow-up at three years was not part of the original study goals. Developmental index scores, rates of cerebral palsy (CP), and rates of adverse outcome (death or moderate to severe delay in development and/or disabling CP) were compared between the eight study groups and between groups combined by dosage level, and between infants with and without T4 supplementation.

RESULTS

Of 166 randomized infants, 32 (19%) died in the neonatal period. Of the 134 survivors, follow-up results were available for 89 children (66%). Mental and motor development and rates of cerebral palsy did not differ in any of the comparisons made.

CONCLUSION

In this study, no differences in neurodevelopment were found in relation to thyroid hormone treatment, but power was insufficient to detect any but very large differences.

Intraventricular hemorrhage and neurodevelopmental outcomes in extreme preterm infants

OBJECTIVE

Not many large studies have reported the true impact of lower-grade intraventricular hemorrhages in preterm infants. We studied the neurodevelopmental outcomes of extremely preterm infants in relation to the severity of intraventricular hemorrhage.

METHODS

A regional cohort study of infants born at 23 to 28 weeks' gestation and admitted to a NICU between 1998 and 2004. Primary outcome measure was moderate to severe neurosensory impairment at 2 to 3 years' corrected age defined as developmental delay (developmental quotient >2 SD below the mean), cerebral palsy, bilateral deafness, or bilateral blindness.

RESULTS

Of the 1472 survivors assessed, infants with grade III-IV intraventricular hemorrhage (IVH; n = 93) had higher rates of developmental delay (17.5%), cerebral palsy (30%), deafness (8.6%), and blindness (2.2%). Grade I-II IVH infants (n = 336) also had increased rates of neurosensory impairment (22% vs 12.1%), developmental delay (7.8% vs 3.4%), cerebral palsy (10.4% vs 6.5%), and deafness (6.0% vs 2.3%) compared with the no IVH group (n = 1043). After exclusion of 40 infants with late ultrasound findings (periventricular leukomalacia, porencephaly, ventricular enlargement), isolated grade I-II IVH (n = 296) had increased rates of moderate-severe neurosensory impairment (18.6% vs 12.1%). Isolated grade I-II IVH was also independently associated with a higher risk of neurosensory impairment (adjusted odds ratio 1.73, 95% confidence interval 1.22-2.46).

CONCLUSIONS

Grade I-II IVH, even with no documented white matter injury or other late ultrasound abnormalities, is associated with adverse neurodevelopmental outcomes in extremely preterm infants.

Antecedents of perinatal cerebral white matter damage with and without intraventricular hemorrhage in very preterm newborns

BACKGROUND

Isolated periventricular leukomalacia, defined as periventricular leukomalacia unaccompanied by intraventricular hemorrhage, is reportedly increased in newborns with systemic hypotension and in infants who received treatment for systemic hypotension or a patent ductus arteriosus.

METHODS

This study sought to determine if the risk profile of one or more hypoechoic lesions unaccompanied by intraventricular hemorrhage, our surrogate for isolated periventricular leukomalacia, differs from that of one or more hypoechoic lesions preceded or accompanied by intraventricular hemorrhage. We compared extremely preterm infants (i.e., gestation 23-27 weeks) with each of these entities to 885 extremely preterm infants who had neither an isolated hypoechoic lesion nor a hypoechoic lesion preceded or accompanied by intraventricular hemorrhage.

RESULTS

The risk of a hypoechoic lesion with intraventricular hemorrhage (N = 61) was associated with gestation <25 weeks, high Score for Acute Neonatal Physiology, early recurrent or prolonged acidemia, analgesic exposure, and mechanical ventilation 1 week after birth.

CONCLUSIONS

In this large, multicenter sample of extremely low gestational age newborns, the risk profile of a hypoechoic lesion unaccompanied by intraventricular hemorrhage differed from that of a hypoechoic lesion with intraventricular hemorrhage. This suggests that hypoechoic lesions accompanied or preceded by intraventricular hemorrhage (our surrogate for periventricular hemorrhagic infarction) may have a different causal pathway than hypoechoic lesions without intraventricular hemorrhage, our surrogate for periventricular leukomalacia.

Assessing postural asymmetry with a podoscope in infants with Central Coordination Disturbance

The aim of this study was to digitally evaluate the incidence and severity of postural asymmetry in infants with Central Coordination Disturbance (CCD) by using a computer-aided podoscope (PodoBaby) from CQ Elektronik System. A sample of 120 infants aged from 3 months (± 1 week) to 6 months (± 1 week) took part in the study, of which 60 were diagnosed with CCD by a neurologist using Vojta's method and the remaining half healthy, non-afflicted infants. The relationships between Vojta's method, as a subjective clinical diagnostic tool for assessing the functional performance of infants with CCD, and the postural asymmetry results recorded with the podoscope, were also defined. Each infant was placed on the podoscope and photographed underneath in two positions: first lying on their back and then on their stomach. A symmetry index was used to calculate body asymmetry, i.e., the percent difference of abnormal body posture by favoring one side of the body to the other. The results confirmed that postural asymmetry assessed by the PodoBaby was in line with the earlier clinical diagnosis using Vojta's method. Statistically significant differences in postural asymmetry were also found between the healthy infants and infants with CCD. In addition, significant relationships were demonstrated in the magnitude and direction of asymmetry in the stomach and back positions.

Early cranial ultrasound lesions predict microcephaly at age 2 years in preterm infants

To assess how well early ultrasound lesions in preterm newborns predict reduced head circumference at 2 years, the investigators followed 923 children born before the 28th week of gestation who were not microcephalic at birth. Six percent of children who had a normal ultrasound scan were microcephalic compared with 15% to 20% who had intraventricular hemorrhage, an echolucent lesion, or ventriculomegaly. The odds ratios (95% confidence intervals) for microcephaly associated with different ultrasound images were intraventricular hemorrhage, 1.5 (0.8-3.0); ventriculomegaly, 3.3 (1.8-6.0); an echodense lesion, 1.6 (0.7-3.5); and an echolucent lesion, 3.1 (1.5-6.2). Ventriculomegaly and an echolucent lesion had very similar low positive predictive values (24% and 27%, respectively) and high negative predictive values (91% and 90%, respectively) for microcephaly. Ventriculomegaly had a higher sensitivity for microcephaly than did an echolucent lesion (24% vs 16%, respectively). Focal white-matter lesion (echolucent lesion) and diffuse white-matter damage (ventriculomegaly) predict an increased risk of microcephaly.