Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants

The validity of hospital diagnostic and procedure codes reflecting morbidity in preterm neonates born <32 weeks gestation

OBJECTIVE

To determine the validity of diagnostic hospital billing codes for complications of prematurity in neonates <32 weeks gestation.

STUDY DESIGN

Retrospective cohort data from discharge summaries and clinical notes (n = 160) were reviewed by trained, blinded abstractors for the presence of intraventricular hemorrhage (IVH) grades 3 or 4, periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC), stage 3 or higher, retinopathy of prematurity (ROP), and surgery for NEC or ROP. Data were compared to diagnostic billing codes from the neonatal electronic health record.

RESULTS

IVH, PVL, ROP and ROP surgery had strong positive predictive values (PPV > 75%) and excellent negative predictive values (NPV > 95%). The PPVs for NEC (66.7%) and NEC surgery (37.1%) were low.

CONCLUSION

Diagnostic hospital billing codes were observed to be a valid metric to evaluate preterm neonatal morbidities and surgeries except in the instance of more ambiguous diagnoses such as NEC and NEC surgery.

Preterm brain Injury: White matter injury

Despite the advances in neonatal intensive care, the preterm brain remains vulnerable to white matter injury (WMI) and disruption of normal brain development (i.e., dysmaturation). Compared to severe cystic WMI encountered in the past decades, contemporary cohorts of preterm neonates experience milder WMIs. More than destructive lesions, disruption of the normal developmental trajectory of cellular elements of the white and the gray matter occurs. In the acute phase, in response to hypoxia-ischemia and/or infection and inflammation, multifocal areas of necrosis within the periventricular white matter involve all cellular elements. Later, chronic WMI is characterized by diffuse WMI with aberrant regeneration of oligodendrocytes, which fail to mature to myelinating oligodendrocytes, leading to myelination disturbances. Complete neuronal degeneration classically accompanies necrotic white matter lesions, while altered neurogenesis, represented by a reduction of the dendritic arbor and synapse formation, is observed in response to diffuse WMI. Neuroimaging studies now provide more insight in assessing both injury and dysmaturation of both gray and white matter. Preterm brain injury remains an important cause of neurodevelopmental disabilities, which are still observed in up to 50% of the preterm survivors and take the form of a complex combination of motor, cognitive, and behavioral concerns.

Lenticulostriate vasculopathy in preterm infants: a new classification, clinical associations and neurodevelopmental outcome

OBJECTIVE

To examine the inter-rater reliability for the diagnosis of LSV on cranial ultrasound (cUS), determine the risk factors associated with LSV and its progression, and examine neurodevelopmental outcome.

STUDY DESIGN

Prospective case-control study of neonates ≤32wks of gestation assessed for LSV by serial cUS (n = 1351) between 2012 and 2014 and their neurodevelopment at 18-36mon-corrected age compared to controls.

RESULTS

Agreement for LSV on cUS improved from Κappa 0.4-0.7 after establishing definitive criteria and guidelines. BPD was the only variable associated with the occurrence and the progression of LSV. Cytomegalovirus (CMV) infection occurred in one neonate (1.5%). Neurodevelopmental outcome of neonates with LSV did not differ from controls.

CONCLUSIONS

Establishment of well-defined stages of LSV improves the reliability of the diagnosis and allows identification of neonates with progression of LSV. Although LSV was associated with BPD, it was not associated with congenital CMV infection.

Alterations in white matter microstructure are associated with goal-directed upper-limb movement segmentation in children born extremely preterm

Altered white matter microstructure is commonly found in children born preterm (PT), especially those born at an extremely low gestational age (GA). These children also commonly show disturbed motor function. This study explores the relation between white matter alterations and upper-limb movement segmentation in 41 children born PT (19 girls), and 41 children born at term (18 girls) at 8 years. The PT group was subdivided into extremely PT (E-PT; GA = 25-27 weeks, N = 10), very PT (V-PT; GA = 28-32 weeks, N = 13), and moderately PT (M-PT; GA = 33-35 weeks, N = 18). Arm/hand preference (preferred/non-preferred) was determined through object interactions and the brain hemispheres were designated accordingly. White matter alterations were assessed using diffusion tensor imaging in nine areas, and movement segmentation of the body-parts head, shoulder, elbow, and wrist were registered during a unimanual goal-directed task. Increased movement segmentation was demonstrated consistently on the preferred side in the E-PT group compared with the term born group. Also compared with the term born peers, the E-PT group demonstrated reduced fractional anisotropy (FA) in the cerebral peduncle (targeting the corticospinal tract) in the hemisphere on the non-preferred side and in the splenium of corpus callosum. In contrast, in the anterior internal capsule on the preferred side, the E-PT group had increased FA. Lower FA in the cerebral peduncle, but higher FA in the anterior internal capsule, was associated with increased movement segmentation across body-parts in a contralateral manner. The results suggest that impaired development of sensorimotor tracts in E-PT children could explain a sub-optimal spatiotemporal organization of upper-limb movements. Hum Brain Mapp 38:5051-5068, 2017. © 2017 Wiley Periodicals, Inc.

The Role of Prematurity in Patients With Hemiplegic Cerebral Palsy

A multicenter retrospective study was conducted to investigate the perinatal factors, imaging findings and clinical characteristics of hemiplegic cerebral palsy with a particular focus on children born prematurely. Our cohort included 135 patients of whom 42% were born prematurely; 16% were extreme premature infants who were born at 30 weeks or earlier. Nineteen (14%) were twins. Right hemiplegia was slightly more common and accounted for 59% of the patients. Imaging findings of intraventricular hemorrhage and periventricular leukomalacia were more prevalent in premature children whereas stroke, porencephaly, cerebral hemorrhage and cerebral atrophy were more evenly distributed in both term-born and prematurely-born children (p< 0.01). The overall prevalence of epilepsy in the cohort was 26% with no differences in full-term compared to prematurely-born children. Regardless of the gestational birth age, intellectual deficits were more common in the presence of comorbidity of both hemiplegia and epilepsy (p< 0.05).

Lenticulostriate vasculopathy in neonates: Perspective of the radiologist

Lenticulostriate vasculopathy (LSV) is a diagnosis dependent on neonatal cranial ultrasound (US). The diagnosis of LSV requires the presence of linear or branching echogenicities in the area of the basal ganglia and/or thalamus on gray scale cranial US. Although the diagnosis of LSV is dependent on cranial US, there are no convincing correlates observed on either computerized tomography or magnetic resonance imaging. Moreover, the radiographic criteria for LSV on cranial US remain vague, and intra-observer correlations are generally reported to be poor. The purpose of this review is to examine the issues associated with the use of cranial US and the diagnosis of LSV, including alternative imaging, clinical abnormalities and the significance of LSV on cranial US.

Lenticulostriate vasculopathy in extremely low gestational age newborns: Inter-rater variability of cranial ultrasound readings, antecedents and postnatal characteristics

Although lenticulostriate vasculopathy (LSV) was first detected on a cranial ultrasound nearly 30 years ago, its clinical implications and significance remain unknown. The objective of this study was to evaluate the inter-rater reliability of cranial ultrasound readings of LSV, and to explore relationships with potential antecedents and developmental correlates in extremely low gestational age newborns. Of the 1506 infants enrolled during the years 2002-2004, 1450 had at least one set of ultrasound scans evaluated for LSV and 939 had all three sets. To evaluate the inter-rater agreement for identifying LSV, we compared readings from two independent radiologists on days 1-4, 5-14, and on or after day 15. We then evaluated the relationships between LSV and maternal, antenatal, and postnatal characteristics. Our results showed that kappa values were 0.18, 0.33, and 0.36 on days 1-4, days 5-14, and day 15 or greater. Infants who were identified as LSV positive by two readers had higher Score for Neonatal Acute Physiology-II (an illness severity indicator), higher rates of tracheal infection and bacteremia, lower partial pressure of arterial oxygen and pH levels on 2 of the first 3 postnatal days, and they were more likely to have a lower psycho-motor development index at age 2 years. Positive agreement on the presence of LSV was low, as was the kappa value, an index of inter-rater reliability. Infants with high illness severity scores and their correlates were at increased risk of developing LSV, while those who develop LSV appear to be at increased risk of motor dysfunction.

Focal necrosis and disturbed myelination in the white matter of newborn infants: a tale of too much or too little oxygen

White matter disease in preterm infants comes along with focal destructions or with diffuse myelination disturbance. Recent experimental work with transgenic mice paves the way for a unifying molecular model for both types of brain injury, placing oxygen sensing by oligodendrocyte precursor cells (OPCs) at the center stage. Mice genetically altered to mimic high local oxygen tension in oligodendroglia lineage cells (via deletion of hypoxia-inducible factor, HIF) develop white matter disease resembling cystic periventricular leukomalacia within the first 7 days of life. Mice in which local hypoxia is mimicked in oligodendroglial cells (via genetic inhibition of HIF decay) display arrested OPC maturation and subsequent hypomyelination, reminiscent of the diffuse white matter disease observed in preterm infants and infants with congenital heart disease. These recent experimental findings on oxygen sensing and myelination are awaiting integration into a clinical framework. Gene regulation in response to hyperoxia or hypoxia, rather than oxidative stress, may be an important mechanism underlying neonatal white matter disease.

[Ages of sitting up and walking in preterm newborns less than 1,500 G with bronchopulmonary dysplasia]

INTRODUCTION

Adverse neurological events in very low birth weight (VLBW) children with bronchopulmonary dysplasia (BPD) are more frequent than in children without. An understanding of the ages when preterm infants acquire certain motor skills will give parents more appropriate information on motor development. The objective of the present study is to estimate the influence between BPD and the age of acquisition of sitting unsupported and independent walking in VLBW children with normal neurological examination at 2 years of corrected age.

PATIENTS AND METHODS

A longitudinal study was conducted on a cohort of 885 children with VLBW, admitted to the Hospital "12 de Octubre" between January 1991 and December 2003. Age for both skills was established by interview with parents. Means were compared with t-test and Bonferroni adjustment where appropriate.

RESULTS

Both motor skills were acquired later in the group with BPD (7.8±2m vs. 7.1±1.3m for sitting unsupported and 14.5±3.8m vs. 13.4±2.5m for walking) (P<.001). BPD was associated with delayed acquisition (above p90) of these skills, OR=2.6 (1.6-4.1) for sitting and OR=2.8 (1.6-4.8) for walking. Association was found after adjusting for gestational age (GA) and weight.

CONCLUSION

BPD was associated with delayed acquisition of both skills in VLBW children with normal neurological examination at 2 years.

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

PURPOSE

To evaluate reader variability of white matter lesions seen on cranial sonographic scans of extreme low gestational age neonates (ELGANs).

METHODS

In 1,452 ELGANs, cranial sonographic scans were obtained in the first and second postnatal weeks, and between the third postnatal week and term. All sets of scans were read independently by two sonologists. We reviewed the use of four diagnostic labels: early periventricular leucomalacia, cystic periventricular leucomalacia, periventricular hemorrhagic infarction (PVHI), and other white matter diagnosis, by 16 sonologists at 14 institutions. We evaluated the association of these labels with location and laterality of hyperechoic and hypoechoic lesions, location of intraventricular hemorrhage, and characteristics of ventricular enlargement.

RESULTS

Experienced sonologists differed substantially in their application of the diagnostic labels. Three readers applied early periventricular leucomalacia to more than one fourth of all the scans they read, whereas eight applied this label to ≤5% of scans. Five applied PVHI to ≥10% of scans, while three applied this label to ≤5% of scans. More than one third of scans labeled cystic periventricular leucomalacia had unilateral hypoechoic lesions. White matter abnormalities in PVHI were more extensive than in periventricular leucomalacia and were more anteriorly located. Hypoechoic lesions on late scans tended to be in the same locations, regardless of the diagnostic label applied.

CONCLUSIONS

Experienced sonologists differ considerably in their tendency to apply diagnostic labels for white matter lesions. This is due to lack of universally agreed-upon definitions. We recommend reducing this variability to improve the validity of large multicenter studies.

The ELGAN study of the brain and related disorders in extremely low gestational age newborns

BACKGROUND

Extremely low gestational age newborns (ELGANs) are at increased risk for structural and functional brain abnormalities.

AIM

To identify factors that contribute to brain damage in ELGANs.

STUDY DESIGN

Multi-center cohort study.

SUBJECTS

We enrolled 1506 ELGANs born before 28 weeks gestation at 14 sites; 1201 (80%) survived to 2 years corrected age. Information about exposures and characteristics was collected by maternal interview, from chart review, microbiologic and histological examination of placentas, and measurement of proteins in umbilical cord and early postnatal blood spots.

OUTCOME MEASURES

Indicators of white matter damage, i.e. ventriculomegaly and echolucent lesions, on protocol cranial ultrasound scans; head circumference and developmental outcomes at 24 months adjusted age, i.e., cerebral palsy, mental and motor scales of the Bayley Scales of Infant Development, and a screen for autism spectrum disorders.

RESULTS

ELGAN Study publications thus far provide evidence that the following are associated with ultrasongraphically detected white matter damage, cerebral palsy, or both: preterm delivery attributed to preterm labor, prelabor premature rupture of membranes, or cervical insufficiency; recovery of microorganisms in the placenta parenchyma, including species categorized as human skin microflora; histological evidence of placental inflammation; lower gestational age at delivery; greater neonatal illness severity; severe chronic lung disease; neonatal bacteremia; and necrotizing enterocolitis.

CONCLUSIONS

In addition to supporting a potential role for many previously identified antecedents of brain damage in ELGANs, our study is the first to provide strong evidence that brain damage in extremely preterm infants is associated with microorganisms in placenta parenchyma.

Age of sitting unsupported and independent walking in very low birth weight preterm infants with normal motor development at 2 years

AIMS

The aims of this study is to (i) determine the age of sitting unsupported and independent walking in preterm infants with birth weight under 1500 g (very low birth weight, VLBW); (ii) estimate differences between VLBW children and a reference population and (iii) estimate the association between clinical characteristics and late age at sitting and walking.

METHODS

A longitudinal study was conducted of a cohort of 876 children with VLBW. The World Health Organization (WHO) motor development study population was used as a reference. Ages for both skills were established by interview with parents. Means were compared with t-test, ANOVA and Bonferroni adjustment where appropriate.

RESULTS

The inclusion criteria were complied with 694 patients; 50% of VLBW sat at 7 m corrected age (CA) and walked at 13 m CA. Both motor skills were acquired later (7.3 +/- 1.5 and 13.6 +/- 2.8 m) compared with the control group (6 +/- 1.1 and 12.1 +/- 1.8 m). Weight or head circumference at birth below the 10th percentile or the presence of bronchopulmonary dysplasia were associated with delayed acquisition of both skills.

CONCLUSION

Very low birth weight infants typically sit unsupported and walk later than term infants. Tables describing reference values for milestones acquisition for different categories of infants (gestational age, birth weight and other determinants) may contribute to inform the decision making process on access to available resources.

Bronchopulmonary dysplasia and brain white matter damage in the preterm infant: a complex relationship

We analysed the relationship between bronchopulmonary dysplasia (BPD) and brain white matter damage (WMD) in very preterm infants, adjusting for common risk factors and confounders. We studied a cohort of infants <32 weeks gestational age (GA) and <1500 g, admitted to 12 hospitals in Northern Italy in 1999-2002. The association between BPD and WMD was estimated by generalised estimating equations and conditional logistic models, adjusting for centre, GA, propensity score for prolonged ventilation and other potential confounders. Directed acyclic graphs (DAG) were used to depict the underlying causal structure and guide analysis. Of the 1209 infants reaching 36 weeks, 192 (15.8%) developed BPD (supplemental oxygen at 36 weeks) and 88 (7.3%) ultrasound-defined WMD (cystic periventricular leukomalacia). In crude analysis, BPD was a strong risk factor for WMD [odds ratio (OR) = 5.9]. With successive adjustments, the OR progressively decreased to 3.88 when adjusting for GA, to 2.72 adding perinatal risk factors, and further down to 2.16 [95% confidence interval 1.1, 3.9] when ventilation was also adjusted for. Postnatal factors did not change the OR. Significant risk factors for WMD, in addition to BPD, were a low GA, a lower Apgar score, a higher illness severity score, ventilation and early-onset sepsis, while antenatal steroids, being small for GA, and surfactant were associated with a reduced risk. In conclusion, our data suggest that BPD is associated with an increased risk of WMD; most of the effect is due to shared risk factors and causal pathways. DAGs helped clarify the complex confounding of this scenario.

''Intraventricular'' hemorrhage and cystic periventricular leukomalacia in preterm infants: how are they related?

Intraventricular hemorrhage and cystic periventricular leukomalacia are often co-occurring characteristics of brain damage in preterm infants. Using data from 1016 infants born before 30 completed weeks' gestational age, we sought to clarify the relationship between severe intraventricular hemorrhage and cystic periventricular leukomalacia, with special emphasis on common antecedents and potential confounding. After comparing risk factors for intraventricular hemorrhage grades 1 through 4 and cystic periventricular leukomalacia, it appears the risk patterns for intraventricular hemorrhage grade 3, intraventricular hemorrhage grade 4, and cystic periventricular leukomalacia differ. The association between intraventricular hemorrhage grade 3 and cystic periventricular leukomalacia differs appreciably from the association between intraventricular hemorrhage grade 4 and cystic periventricular leukomalacia, supporting the notion that intraventricular hemorrhage grade 3 and intraventricular hemorrhage grade 4 are different entities. The presence of intraventricular hemorrhage grade 3 and intraventricular hemorrhage grade 4 increases the risk of cystic periventricular leukomalacia, even after adjusting for potential confounders. This raises the possibility that intraventricular hemorrhage grade 3 and intraventricular hemorrhage grade 4 cause cystic periventricular leukomalacia.

Segmentation of white matter flaring areas in ultrasound images of very-low-birth-weight preterm infants

In this article, we present an interactive algorithm segmenting white brain matter, visible as hyperechoic flaring areas in ultrasound (US) images of preterm infants with periventricular leukomalacia (PVL). The algorithm combines both the textural properties of pathological brain tissue and mathematical morphology operations. An initial flaring area estimate is derived from a multifeature multiclassifier tissue texture classifier. This area is refined based on the structural properties of the choroid plexus, a brain feature known to have characteristics similar to flaring. Subsequently, a combination of a morphological closing, gradient and opening by reconstruction operation determines the final flaring area boundaries. Experimental results are compared with a gold standard constructed from manual flaring area delineations of 12 medical experts. In addition, we compared our algorithm to an existing active contour method. The results show our technique agrees to the gold standard with statistical significance and outperforms the existing method in accuracy. Finally, using the flaring area as a criterion we improve the sensitivity of PVL detection up to 98% as compared with the state of the art.

Observer variability assessing US scans of the preterm brain: the ELGAN study

BACKGROUND

Neurosonography can assist clinicians and can provide researchers with documentation of brain lesions. Unfortunately, we know little about the reliability of sonographically derived diagnoses.

OBJECTIVE

We sought to evaluate observer variability among experienced neurosonologists.

MATERIALS AND METHODS

We collected all protocol US scans of 1,450 infants born before the 28th postmenstrual week. Each set of scans was read by two independent sonologists for the presence of intraventricular hemorrhage (IVH) and moderate/severe ventriculomegaly, as well as hyperechoic and hypoechoic lesions in the cerebral white matter. Scans read discordantly for any of these four characteristics were sent to a tie-breaking third sonologist.

RESULTS

Ventriculomegaly, hypoechoic lesions and IVH had similar rates of positive agreement (68-76%), negative agreement (92-97%), and kappa values (0.62 to 0.68). Hyperechoic lesions, however, had considerably lower values of positive agreement (48%), negative agreement (84%), and kappa (0.32). No sonologist identified all abnormalities more or less often than his/her peers. Approximately 40% of the time, the tie-breaking reader agreed with the reader who identified IVH, ventriculomegaly, or a hypoechoic lesion in the white matter. Only about 25% of the time did the third party agree with the reader who reported a white matter hyperechoic lesion.

CONCLUSION

Obtaining concordance seems to be an acceptable way to assure reasonably high-quality of images needed for clinical research.

Magnesium sulphate given before very-preterm birth to protect infant brain: the randomised controlled PREMAG trial*

OBJECTIVE

To evaluate whether magnesium sulphate (MgSO(4)) given to women at risk of very-preterm birth would be neuroprotective in preterm newborns and would prevent neonatal mortality and severe white-matter injury (WMI).

DESIGN

A randomised study.

SETTING

Eighteen French tertiary hospitals. Population Women with fetuses of gestational age < 33 weeks whose birth was planned or expected within 24 hours were enrolled from July 1997 to July 2003 with follow up of infants until hospital discharge. METHODS Five hundred and seventy-three mothers were randomly assigned to receive a single 40-ml infusion of 0.1 g/ml of MgSO(4) (4 g) solution or isotonic 0.9% saline (placebo) over 30 minutes. This study is registered as an International Standard Randomised Controlled Trial, number 00120588.

MAIN OUTCOME MEASURES

The primary endpoints were rates of severe WMI or total mortality before hospital discharge, and their combined outcome. Analyses were based on intention to treat.

RESULTS

After 6 years of enrolment, the trial was stopped. Data from 688 infants were analysed. Comparing infants who received MgSO(4) or placebo, respectively, total mortality (9.4 versus 10.4%; OR: 0.79, 95% CI 0.44-1.44), severe WMI (10.0 versus 11.7%; OR: 0.78, 95% CI 0.47-1.31) and their combined outcomes (16.5 versus 17.9%; OR: 0.86, 95% CI 0.55-1.34) were less frequent for the former, but these differences were not statistically significant. No major maternal adverse effects were observed in the MgSO(4) group.

CONCLUSION

Although our results are inconclusive, improvements of neonatal outcome obtained with MgSO(4) are of potential clinical significance. More research is needed to assess the protective effect of MgSO(4) alone or in combination with other neuroprotective molecules.

[The use of the continuous positive airway pressure for early stabilization in very low birthweight infants]

BACKGROUND

The introduction of continuous positive airway pressure (CPAP) in neonatal units provides a new strategy in the management of infants weighing less than 1500 g, and especially in those weighing less than 1000 g, allowing a reduction in the use of surfactant without negatively affecting prognosis.

OBJECTIVES

To compare the rate of surfactant use in very low birthweight (VLBW) infants before and after the introduction of CPAP for early stabilization. To compare the frequency of pneumothorax, bronchopulmonary dysplasia (BPD), mortality, severe brain injury, length of hospital stay, and days of intubation in both groups of VLBW infants.

METHODS

We performed a before-after study comparing VLBW infants born in a tertiary care hospital in two periods: group 1 consisted of 78 VLBW infants born in 2001 and group 2 consisted of 80 VLBW infants born from June 2003 to February 2004. Group 1 received conventional management (intubation and administration of surfactant in the delivery room). In group 2, CPAP was introduced for early stabilization.

RESULTS

The mean weight was 1059+/-309 g in group 1 and 1127+/-295 g in group 2 (p = 0.15). The mean gestational age was 29 +/- 3.3 weeks in group 1 and 29 +/- 2.8 weeks in group 2 (p = 1). Fifty-four percent of the neonates in group 1 were intubated in the delivery room versus 31 % of those in group 2 (p = 0.004). Surfactant was used in 68 % of neonates in group 1 versus 49 % of those in group 2 (RR = 1.34 [1.06-1.83]). The mean number of days of intubation was 4 +/- 11 in group 1 versus 2.7 6 5.8 in group 2 (p 5 0.15). Bronchopulmonary dysplasia at a corrected age of 36 weeks occurred in 19 % of neonates in group 1 and in 14.5 % of those in group 2 (RR = 1.34 [0.63-2.84]). The mean number of days on oxygen was 34 6 47 and 21 6 25 respectively (p = 0.04). Necrotizing enterocolitis occurred in 3.8 % of neonates in group 1 and in 8.7 % of those in group 2 (RR= 0.43 [0.11-1.63]). The mortality rate and frequency of pneumothorax were similar in both groups. In the subgroup of VLWB infants with a gestation age of < 28 weeks, no differences were found between the two periods.

CONCLUSIONS

The use of CPAP for early stabilization of VLBW infants is not associated with an increase in neonatal morbidity. This therapy allows the use of surfactant to be decreased, and even allows the number of days on oxygen to be reduced, without adverse effects. However, data on long-term follow-up are not yet available.

Inflammation, brain damage and visual dysfunction in preterm infants

Antenatal intrauterine infection and the fetal inflammatory response appear to be important pathogenetic factors in preterm birth and subsequent neonatal disorders of the lung and brain. In this paper, we expand this concept to include visual dysfunction. Although present data tend to support our notion, we suggest that more experimental and epidemiological research is needed to elucidate mechanisms of infection/inflammation-induced damage to the eye and visual brain pathways of preterm infants.

Peso de nascimento como preditor para a gravidade da lesão da substância branca cerebral neonatal

Para analisar a associação entre fatores natais com a gravidade da lesão da substância branca (LSB) cerebral neonatal, controlando o peso de nascimento, identificaram os neonatos pela ultra-sonografia craniana, que foram divididos em: aqueles com evolução da LSC para resolução da imagem ao ultra-som (menor gravidade) e, aqueles que evoluiram com formação de cistos e/ou ventriculomegalia e/ou hemorragia (maior gravidade). Doze variáveis (hiponatremia, anemia, infecção, retinopatia, displasia broncopulmonar, hipoalbuminemia, persistência do canal arterial, audiometria alterada, desconforto respiratório precoce, peso de nascimento <2500g, peso por categoria e prematuridade) tiveram diferenças entre os dois grupos (p<0,05), sendo que 9 (hiponatremia, infecção, retinopatia, hipoalbuminemia, persistência do canal arterial, desconforto respiratório precoce, baixo peso, prematuridade e peso por categorias) se mantiveram estatisticamente diferentes (p<0,01) após análise por regressão logística. Quando analisadas por categoria de peso de nascimento, nenhuma variável demonstrou significância estatística. O estudo sugere que o peso de nascimento é o maior fator - provavelmente o único - associado com gravidade da LSB cerebral neonatal.

Brain white matter lesions correlated to newborns death and lethality

OBJECTIVES: to describe hospital lethality rates and factors correlated to death in neonates with brain white matter lesions. METHODS: a retrospective study was performed from January 1994 to December 2001. Neonates with white brain matter lesions were divided into survival and death groups and their medical files reviewed through the single blind method to determine evolution. Death certificates provided the cause of death. The groups were compared through correlation coefficients. Hospital lethality rate was calculated. RESULTS: ninety three cases of white brain matter lesions and seven deaths were determined. Hospital lethality rate was of 8.2.% (95%CI: 2.4-14.0) independently from lesion occurrence time, and of 10.3% (95%CI: 3.3-17.3) for deaths occurred during prenatal and perinatal periods. Death was correlated to: Apgar score, non-cephalic presentation, gestational age, hyperglicemia, hypercalcemia, convulsion, respiratory insufficiency and atelectasy. CONCLUSIONS: hospital lethality was of 10.3% generating the following hypothesis: perinatal asphyxia must be the principal direct and indirect etiologic factor (aggravating the expression of prematurity and infection diseases), of prenatal and perinatal mortality among newborns with white brain matter lesions; and <7 Apgar score in the 5th minute associated to brain white matter lesions, are markers for perinatal asphyxia diagnosis.

Magnetic resonance and ultrasound brain imaging in preterm infants

Cranial ultrasonography has been used to identify brain injury in preterm neonates for more than two decades. More recently, magnetic resonance imaging has been used to evaluate brain development and pathology in these infants. In this review we describe how well findings from these two imaging modalities agree with histology findings and neuro-developmental outcome. In addition, we discuss studies comparing ultrasound and magnetic resonance imaging findings.

Cerebral palsy in very preterm infants: new epidemiological insights

The focus of this review is on new insights from recent epidemiological research on cerebral palsy in preterm infants. These include: 1) a better understanding of issues related to diagnosis and classification; 2) new information about the brain abnormalities underlying cerebral palsy in preterm infants; and 3) a better understanding of biological mechanisms that may underlie previously described epidemiological associations. Ongoing efforts to improve the diagnosis and classification of cerebral palsy have been enhanced by findings from serial examinations of cohorts of very preterm infants. Cranial ultrasonography through the anterior fontanelle of very preterm infants has provided information about grossly evident brain damage, found in about one-half of preterm infants who develop cerebral palsy. Insights into the pathophysiologic basis for certain epidemiologic associations have come from studies of experimental brain damage in animals and clinical studies of neurologic disorders in adults. Much of the current epidemiological research into the causes of cerebral palsy in preterm infants has focused on two potential mechanisms of brain damage. One mechanism involves insufficient cerebral perfusion; the other, cytokine-mediated damage, potentially triggered by events such as maternal infection (e.g., intrauterine or periodontal infection), neonatal infection (e.g., sepsis and necrotizing enterocolitis), and neonatal oxygen- or ventilator-induced lung injury. In addition to the preterm infant's increased exposure to such damaging factors, the high frequency of cerebral palsy in these infants might be due, in part, to insufficient levels of developmentally regulated protective substances, such as thyroid hormone and glucocorticoids. Models of causation currently are being investigated using recently developed methods for quantifying, with small quantities of blood, biomolecules that are suspected to either promote or protect against brain damage in the neonate. Clinical investigations now under way can be expected to identify strategies to be tested in clinical trials that could lower the risk of cerebral palsy in very preterm infants.