Improved Myelination following Camp Leg Power, a Selective Motor Control Intervention for Children with Spastic Bilateral Cerebral Palsy: A Diffusion Tensor MRI Study

BACKGROUND AND PURPOSE

Children with spastic cerebral palsy have motor deficits associated with periventricular leukomalacia indicating WM damage to the corticospinal tracts. We investigated whether practice of skilled lower extremity selective motor control movements would elicit neuroplasticity.

MATERIALS AND METHODS

Twelve children with spastic bilateral cerebral palsy and periventricular leukomalacia born preterm (mean age, 11.5 years; age range, 7.3-16.6 years) participated in a lower extremity selective motor control intervention, Camp Leg Power. Activities promoted isolated joint movement including isokinetic knee exercises, ankle-controlled gaming, gait training, and sensorimotor activities (3 hours/day, 15 sessions, 1 month). DWI scans were collected pre- and postintervention. Tract-Based Spatial Statistics was used to analyze changes in fractional anisotropy, radial diffusivity, axial diffusivity, and mean diffusivity.

RESULTS

Significantly reduced radial diffusivity (P < . 05) was found within corticospinal tract ROIs, including 28.4% of the left and 3.6% of the right posterior limb of the internal capsule and 14.1% of the left superior corona radiata. Reduced mean diffusivity was found within the same ROIs (13.3%, 11.6%, and 6.6%, respectively). Additionally, decreased radial diffusivity was observed in the left primary motor cortex. Additional WM tracts had decreased radial diffusivity and mean diffusivity, including the anterior limb of the internal capsule, external capsule, anterior corona radiata, and corpus callosum body and genu.

CONCLUSIONS

Myelination of the corticospinal tracts improved following Camp Leg Power. Neighboring WM changes suggest recruitment of additional tracts involved in regulating neuroplasticity of the motor regions. Intensive practice of skilled lower extremity selective motor control movements promotes neuroplasticity in children with spastic bilateral cerebral palsy.

Expanding the phenotype of children presenting with hypoventilation with biallelic TBCK pathogenic variants and literature review

Individuals with biallelic TBCK pathogenic variants present in infancy with distinctive facial features, profound hypotonia, severe intellectual impairment and epilepsy. Although rare, it may mimic other neurogenetic disorders leading to extensive investigations. Improved understanding of the clinical phenotype can support early monitoring of complications due to respiratory insufficiency. We present six individuals who were found to have pathogenic biallelic TBCK variants. The clinico-radiological and diagnostic records were reviewed. Five individuals were diagnosed with hypoventilation, requiring respiratory support, highlighting the need for early respiratory surveillance. Characteristic brain imaging in our cohort included periventricular leukomalacia-like changes. We recommend screening for TBCK in hypotonic children with periventricular leukomalacia-like changes, particularly in the absence of prematurity.

The prognosis of refractory hypotension and severe intraventricular hemorrhage in very low birth weight infants

BACKGROUND

The increased survival rate among very low birth weight infants has resulted in a higher risk for developing neuro-complications such as intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and adverse neurodevelopmental outcomes.

PURPOSE

We examined refractory hypotension experienced within a week of life in association with severe IVH (grades 3-4) among very low birth weight infants (VLBWIs).

METHOD

Between Jan 2014 and Dec 2017, the clinical data of 191 VLBWIs were retrospectively chart reviewed. Of a total of 191 VLBWIs, 71.2% (136/191) had IVH, and 28.7% (55/191) had severe IVH.

RESULTS

The VLBWI with severe IVH group (grade 3-4) presented with a significantly lower gestational age along with higher use of postnatal hydrocortisone for refractory hypotension within a week of life. Resuscitation at delivery, pulmonary hemorrhage, neonatal seizure, and PVL were significantly more frequent in the severe IVH group (P < .05). Higher mortality occurred in the VLBWI with severe IVH group (P < .001). The multivariable logistic regression analysis consistently showed that refractory hypotension within a week of life and neonatal seizures were significantly associated with severe IVH. Those in the severe IVH and refractory hypotension groups had significantly lower composite cognitive, language, motor scores in Bayley Scales of Infant and Toddler Development III scores at corrected 18-24 months.

CONCLUSION

Refractory hypotension within a week of life and seizures were consistently associated with severe IVH and developmental delay at corrected 18-24 months. VLBWI who experienced refractory hypotension within a week of life may indicate a more vulnerable clinical setting with a higher risk for developmental delay.

Recent Investigations on Neurotransmitters' Role in Acute White Matter Injury of Perinatal Glia and Pharmacotherapies-Glia Dynamics in Stem Cell Therapy

Periventricular leukomalacia (PVL) and cerebral palsy are two neurological disease conditions developed from the premyelinated white matter ischemic injury (WMI). The significant pathophysiology of these diseases is accompanied by the cognitive deficits due to the loss of function of glial cells and axons. White matter makes up 50% of the brain volume consisting of myelinated and non-myelinated axons, glia, blood vessels, optic nerves, and corpus callosum. Studies over the years have delineated the susceptibility of white matter towards ischemic injury especially during pregnancy (prenatal, perinatal) or immediately after child birth (postnatal). Impairment in membrane depolarization of neurons and glial cells by ischemia-invoked excitotoxicity is mediated through the overactivation of NMDA receptors or non-NMDA receptors by excessive glutamate influx, calcium, or ROS overload and has been some of the well-studied molecular mechanisms conducive to the injury of white matter. Expression of glutamate receptors (GluR) and transporters (GLT1, EACC1, and GST) has significant influence in glial and axonal-mediated injury of premyelinated white matter during PVL and cerebral palsy. Predominantly, the central premyelinated axons express extensive levels of functional NMDA GluR receptors to confer ischemic injury to premyelinated white matter which in turn invoke defects in neural plasticity. Several underlying molecular mechanisms are yet to be unraveled to delineate the complete pathophysiology of these prenatal neurological diseases for developing the novel therapeutic modalities to mitigate pathophysiology and premature mortality of newborn babies. In this review, we have substantially discussed the above multiple pathophysiological aspects of white matter injury along with glial dynamics, and the pharmacotherapies including recent insights into the application of MSCs as therapeutic modality in treating white matter injury.

Ultrasound imaging of preterm brain injury: fundamentals and updates

Neurosonography has become an essential tool for diagnosis and serial monitoring of preterm brain injury. Preterm infants are at significantly higher risk of hypoxic-ischemic injury, intraventricular hemorrhage, periventricular leukomalacia and post-hemorrhagic hydrocephalus. Neonatologists have become increasingly dependent on neurosonography to initiate medical and surgical interventions because it can be used at the bedside. While brain MRI is regarded as the gold standard for detecting preterm brain injury, neurosonography offers distinct advantages such as its cost-effectiveness, diagnostic utility and convenience. Neurosonographic signatures associated with poor long-term outcomes shape decisions regarding supportive care, medical or behavioral interventions, and family members' expectations. Within the last decade substantial progress has been made in neurosonography techniques, prompting an updated review of the topic. In addition to the up-to-date summary of neurosonography, this review discusses the potential roles of emerging neurosonography techniques that offer new functional insights into the brain, such as superb microvessel imaging, elastography, three-dimensional ventricular volume assessment, and contrast-enhanced US.

Clinical Diagnosis of White Matter Softening in Premature Infants Based on Electroencephalogram (EEG)

Periventricular white matter softening in preterm infants can lead to severe sequelae and greatly affects the quality of life of preterm infants, and early diagnosis is of great clinical significance and value. The purpose of this study is to select a diagnostic test scientifically and rationally, to interpret and evaluate the results of the diagnostic test, and to evaluate the selected diagnostic method. Although DWI is a sensitive method for early diagnosis of PVL, it is not suitable for critical preterm infants. Therefore, according to clinical research data and the basic hardware conditions of our hospital, video EEG was chosen as the target diagnostic test method to explore whether VEEG can be used for early diagnosis of PVL. According to the results of this study, video EEG may play an important role in the early diagnosis of PVL, and it is believed that video EEG can be used as an auxiliary examination tool, especially for some critical preterm infants who are not suitable for DWI examination, and it can be used as an electrophysiological examination index for the preliminary diagnosis of periventricular white matter softening in preterm infants to indicate that the clinic should carry out necessary and appropriate diagnostic tests. The timely intervention and the results of VEEG are valuable for the assessment of the prognosis of critically ill preterm infants as raw data. However, the use of VEEG to screen clinically suspicious PVL preterm infants is a new attempt, and although good results have been achieved in foreign countries, this study has been conducted only recently in China and requires further exploration.

The Management of Myelomeningocele Study: Short-Term Neonatal Outcomes

INTRODUCTION

The Management of Myelomeningocele Study was a multicenter randomized trial to compare prenatal and standard postnatal repair of myelomeningocele (MMC). Neonatal outcome data for 158 of the 183 randomized women were published in The New England Journal of Medicine in 2011.

OBJECTIVE

Neonatal outcomes for the complete trial cohort (N = 183) are presented outlining the similarities with the original report and describing the impact of gestational age as a mediator.

METHODS

Gestational age, neonatal characteristics at delivery, and outcomes including common complications of prematurity were assessed.

RESULTS

Analysis of the complete cohort confirmed the initial findings that prenatal surgery was associated with an increased risk for earlier gestational age at birth. Delivery occurred before 30 weeks of gestation in 11% of neonates that had fetal MMC repair. Adverse pulmonary sequelae were rare in the prenatal surgery group despite an increased rate of oligohydramnios. There was no significant difference in other complications of prematurity including patent ductus arteriosus, sepsis, necrotizing enterocolitis, periventricular leukomalacia, and intraventricular hemorrhage.

CONCLUSION

The benefits of prenatal surgery outweigh the complications of prematurity.

[Effect of pranlukast on neonatal rats with periventricular leukomalacia]

OBJECTIVE

To study the effect of pranlukast (Pran) on neonatal rats with periventricular leukomalacia (PVL).

METHODS

The rats, aged 3 days, were randomly divided into a sham-operation group, a PVL group, and a Pran group. A rat model of PVL was prepared by right common carotid artery ligation and postoperative hypoxia. The rats in the sham-operation group were given isolation of the right common carotid artery without ligation or hypoxic treatment. The rats in the Pran group were given intraperitoneal injection of Pran (0.1 mg/kg) once every 12 hours, for 3 consecutive days, and those in the sham-operation group and the PVL group were given intraperitoneal injection of an equal volume of normal saline. On day 14 after modeling, hematoxylin-eosin (HE) staining was used to observe the pathological changes of brain tissue; immunofluorescent staining was used to measure the expression of myelin basic protein (MBP) in brain tissue (n=8); Western blot was used to measure the expression of cyclic nucleotide phosphodiesterase (CNPase), MBP, and G protein-coupled receptor 17 (GPR17) (n=8). On day 21 after modeling, Morris water maze test was used to evaluate the learning and memory abilities of rats in each group (n=8).

RESULTS

The results of HE staining showed that the PVL group had greater pathological changes of white matter than the sham-operation group, and compared with the PVL group, the Pran group had a significant improvement in such pathological changes. The results of immunofluorescence assay showed that the PVL group had a lower mean fluorescence intensity of MBP than the sham-operation group (P<0.05), and the Pran group had a higher mean fluorescence intensity of MBP than the PVL group (P<0.05). Western blot showed that compared with the sham-operation group, the PVL group had significantly lower relative expression of MBP and CNPase (P<0.05) and significantly higher relative expression of GPR17 (P<0.05), and compared with the PVL group, the Pran group had significantly higher relative expression of MBP and CNPase (P<0.05) and significantly lower relative expression of GPR17 (P<0.05). Morris water maze test showed that compared with the sham-operation group, the PVL group had a significant increase in escape latency and a significant reduction in the number of platform crossings, and compared with the PVL group, the Pran group had a significant reduction in escape latency and a significant increase in the number of platform crossings (P<0.05).

CONCLUSIONS

Pran can alleviate brain damage, promote myelination, and improve long-term learning and memory abilities in neonatal rats with PVL, possibly by reducing the expression of GPR17.

Effects of Interferon-γ and Tumor Necrosis Factor-α on Survival and Differentiation of Oligodendrocyte Progenitors

OBJECTIVE

There is strong evidence from recent clinical studies that ascending intrauterine infection is associated with an increased incidence of periventricular leukomalacia in very premature fetuses. Periventricular leukomalacia is characterized by disrupted myelination from a loss of oligodendrocyte progenitors. We investigated the effects of proinflammatory cytokines on the survival and differentiation of this cell type.

METHODS

Cultures of more than 90% A2B5-positive progenitors were prepared from neonatal rats and kept for 3 days in medium supplemented with factors that stimulate cell proliferation. After 1 day in proliferation medium, cells were treated with interferon-gamma (100 U/mL) and tumor necrosis factor-alpha (100 ng/mL) for 48 hours triggering an increase in apoptotic A2B5 progenitor cells from 3.2 +/- 2.3% to 11.0 +/- 2.6%. After cytokine treatment cultures were transferred to medium containing factors to promote differentiation of progenitors into the myelinating phenotype.

RESULTS

In cytokine pretreated cultures, only 2.6 +/- 1.1% of total cells survived after a total of 9 days in vitro, whereas in untreated cultures most cells differentiated as shown by expression of myelin basic protein, myelin-associated glycoprotein, 2,3-cyclic nucleotide 3-phosphodiesterase, and myelin oligodendrocyte-specific protein. Using ten-fold reduced concentrations of combined interferon-gamma (10 U/mL) and tumor necrosis factor-alpha (10 ng/mL) pretreatment resulted in a survival to 11.2 +/- 4.9% of total cells with 36.3 +/- 11.6% A2B5-positive cells at day 9. This indicates a major enrichment of undifferentiated cells compared with untreated controls which harbored only 1.0 +/- 0.3% A2B5-positive cells.

CONCLUSION

Inflammatory cytokines not only induced apoptotic cell death but also prevented the differentiation of immature A2B5 oligodendrocyte progenitors into the myelinating phenotype.

Network of Northwest Neonatal Professional Collaboration Group. [Epidemiological survey of neonatal respiratory distress syndrome in part of northwest regions in China]

OBJECTIVE

To investigate the status of admission and treatment of neonatal respiratory distress syndrome (RDS) in northwest regions in China.

METHOD

Twenty hospitals (6 secondary hospitals, 2 tertiary grade B hospitals and 12 tertiary grade A hospitals) from 3 regions participated in the retrospective investigation. Data of infants with RDS and age ≤3 days admitted to neonatal intensive care units (NICUs) of participated hospitals from January 1, 2011 to December 31, 2011 were collected by using descriptive epidemiologic survey methodology. The investigation included the basic information of children, perinatal risk factors, clinical manifestations and treatment, complications and prognosis.

RESULT

Of the 17 406 infants admitted to the 20 hospitals under investigation, 580 neonates (3.3%) suffered from RDS and 379 (65.3%) of them were males. Their average gestational age (GA) was (33.0±2.9) weeks and birth weight (BW) was (1 956±647)g. The average age of their mothers was (28±5) years, 19 (3.3%) infants with RDS were conceived with assisted reproductive technologies (ART). The selective cesarean section rate of mothers with gestational age ≥ 37 weeks was 59.3 % (51/86). The median duration and cost of the hospitalization were 13 (6.0, 21.0) days and 14 200 (6 800, 23 200) yuan. The common perinatal risk factors in the order of occurrence rate were 33.1% (192/580) cases of birth asphyxia, 19.7% (114 /580) cases of multiple births, 17.8% (103/580) cases of gestational hypertension, 15.2% (88/580) cases of fetal distress, 13.3% (77/580) cases of premature rupture, 5.7% (33/580) cases of placental abruption, 1.6% (9/580) cases of gestational diabetes, 1.4% (8/580) cases of intrahepatic cholestasis in pregnancy; 23.6% (33/140) cases in Gansu were treated with antenatal steroids, 12.1% (8/66) cases in Xinjiang and 9.4% (25/265) cases in Shaanxi. Shaanxi had the highest rate of applying pulmonary surfactant (PS) and intubate-surfactant-extubate to CPAP (INSURE), 61.6% (226/367) and 57.3% (142/248) respectively, but they had the lowest dosage of PS (80±43) mg/kg. Hospitals in Shaanxi used CPAP as the major assisted ventilation mode (87.5%, 294/336), with the maximum ventilation duration, the median was 67.0 (43.7, 108.7) hours. Hospitals in Xinjiang had the lowest rate of applying PS and INSURE, 27.3% (18/66) and 19.6% (10/51) cases respectively, but they had the largest dosage of PS (170±32) mg/kg. In Xinjiang, conventional mechanical ventilation was used as the major assisted ventilation mode (60.5%, 23/28) and the median of ventilation duration 24.0 (0.0, 60.0) hours was the shortest in the three regions. Hospitals in Gansu had the longest time of using PS, the median was 24 (7.0, 24.0) hours and also had the highest rate of applying assisted ventilation (94.6%, 139/147). The three regions had significant differences in the application of PS, mode of assistant ventilation and duration (χ(2)=40.572, 54.271, 29.529, P all<0.05). The common complications included hypoxic ischemic encephalopathy (HIE, 20.3% (104/513)), intraventricular hemorrhage (IVH,14.3%(71/498)), patent ductus arteriosus (PDA, 9.2%(48/522)), pulmonary hemorrhage (6.1%, 32/526), necrotizing enterocolitis (NEC, 4.6%(22/476)), bronchopulmonary dysplasia (BPD, 3.4%(17/502)), periventricular leukomalacia (PVL, 2.5%(12/488)), and lung leakage (1.3%, 7/531). The total mortality rate of RDS infants was 14.7% (85/580). Of the 85, 65 died after abandoning of treatment, accounting for 76.5%. The abandoning rate in Xinjiang was much higher (59.1%, 39/66) than those in Shaanxi (8.7%, 32/367) and Gansu (18.4%, 27/147). The difference was statistically significant (χ(2)=21.237, P<0.05).

CONCLUSION

The infants with RDS have greater average gestational age and weight. Problems found include incomplete prenatal examination, the high elective cesarean section rate of full-term infants with RDS, the low antepartum application rate of antenatal steroids, the non-standard use of PS, the low level of using INSURE, inadequate knowledge of complications as well as underdeveloped examination methods. The abandoning of treatment is the major cause of death. Therefore, we suggest that the government should list pulmonary surfactant among the medical insurance covered medicines to lower the rate of the family giving up the RDS infants because of economic difficulties.

[The morbidities of extremely preterm and extremely low birth weight infants during hospitalization]

OBJECTIVE

Extremely preterm (EP) and extremely low birth weight infants (ELBWI) tended to suffer from some serious complications. How to treat and make them survive reflect the progress of perinatal medicine and neonatal treatment technology. But in our country, there was still lack of data analysis about the morbidities and interventions of large sample survey on such infants. This study was designed to survey the in-hospital morbidities of EP and ELBWI who had been admitted to neonatology departments.

METHOD

Clinical data of EP (gestational age < 28 weeks) and ELBWI (birth weight < 1 000 g), who were discharged from January 1, 2008 to December 31, 2012, were collected retrospectively from twenty tertiary neonatology departments in Guangdong province. The rates of major in-hospital morbidities such as neonatal asphyxia, neonatal respiratory distress syndrome (NRDS), bronchopulmonary dysplasia (BPD, oxygen therapy at postnatal 28d), hospital-acquired infection (HAI), periventricular-intraventricular hemorrhages (PVH-IVH), periventricular leukomalacia (PVL), retinopathy of prematurity (ROP) and necrotizing enterocolitis (NEC) etc. were summarized and calculated respectively. Comparisons were made among subgroups according to areas of hospitalization, and infants of small for gestational age (SGA) and appropriate for gestational age (AGA). Categorical data were analyzed using the chi-square test, and P < 0.05 were considered statistically significant.

RESULT

Totally 888 cases were enrolled in the study, including 498 EP and 683 ELBWIs (while 293 cases were both EP and ELBWIs). The mean gestational ages were (27.6±1.7) weeks (22(+6)-35 weeks), and mean birth weights were (928±154) g (300-1 480 g); 57.7% (512/888) of them were male while 42.3% (376/888) were female. The major in-hospital morbidity rates of EP were NRDS 80.3% (400/498), BPD 54.6% (113/207), PVH-IVH 40.8% (111/272), ROP 40.7% (92/226), HAI 28.1% (99/352), Apgar score ≤7 at five minutes 19.6% (87/445), PVL 14.7% (40/272) and NEC 9.4% (37/393), while ELBWI were NRDS 75.5% (516/683), BPD 50.2% (153/305), ROP 31.6% (103/326), HAI 30.3% (149/491), PVH-IVH 29.6% (111/375), PVL 21.9% (82/375), Apgar score ≤7 at five minutes 20.3% (125/617) and NEC 12.2% (66/542). There were 69.2% (614/888) and 79.7% (708/888) of all infants received pulmonary surfactant therapy and ventilator therapy respectively. Infants stayed in the hospitals in Guangzhou and Shenzhen had higher morbidity rates in NRDS (80.6% (382/474) vs. 72.9% (302/414), χ(2)=7.297, P=0.007), BPD (57.7% (146/253) vs. 28.2%(48/170), χ(2)=35.571, P <0.01), ROP (40.9% (114/272) vs. 14.1%(29/205), χ(2)=42.931, P <0.01) and PVH-IVH (34.8% (110/316) vs. 19.5% (48/246), χ(2)=16.017, P <0.01), but had lower rate in PVL (10.1% (32/316) vs. 25.2% (62/246), χ(2)=22.537, P <0.01) than those from other cities. The SGA infants had lower morbidity rates in NRDS (62.9% (149/237) vs. 82.7% (512/619), χ(2)=38.368, P <0.01), ROP (21.7% (25/115) vs. 33.0% (115/349), χ(2)=5.161, P =0.023) and PVH-IVH (13.8% (21/152) vs. 33.3% (132/396), χ(2)=20.791, P <0.01) than AGA infants.

CONCLUSION

The in-hospital morbidity rates of EP and ELBWI were really high, and NRDS had the highest rate of all. The morbidities could be influenced by many factors which should be managed comprehensively.

Abnormal cerebral structure is present at term in premature infants

BACKGROUND

Long-term studies of the outcome of very prematurely born infants have clearly documented that the majority of such infants have significant motor, cognitive, and behavioral deficits. However, there is a limited understanding of the nature of the cerebral abnormality underlying these adverse neurologic outcomes.

AIM

The overall aim of this study was to define quantitatively the alterations in cerebral tissue volumes at term equivalent in a large longitudinal cohort study of very low birth weight premature infants in comparison to term-born infants by using advanced volumetric 3-dimensional magnetic resonance imaging (MRI) techniques. We also aimed to define any relationship of such perinatal lesions as white matter (WM) injury or other potentially adverse factors to the quantitative structural alterations. Additionally, we wished to identify the relationship of the structural alterations to short-term neurodevelopmental outcome.

METHODS

From November 1998 to December 2000, 119 consecutive premature infants admitted to the neonatal intensive care units at Christchurch Women's Hospital (Christchurch, New Zealand) and the Royal Women's Hospital (Melbourne, Australia) were recruited (88% of eligible) after informed parental consent to undergo an MRI scan at term equivalent. Twenty-one term-born infants across both sites were recruited also. Postacquisition advanced 3-dimensional tissue segmentation with 3-dimensional reconstruction was undertaken to estimate volumes of cerebral tissues: gray matter (GM; cortical and deep nuclear structures), WM (myelinated and unmyelinated), and cerebrospinal fluid (CSF).

RESULTS

In comparison to the term-born infants, the premature infants at term demonstrated prominent reductions in cerebral cortical GM volume (premature infants [mean +/- SD]: 178 +/- 41 mL; term infants: 227 +/- 26 mL) and in deep nuclear GM volume (premature infants: 10.8 +/- 4.1 mL; term infants: 13.8 +/- 5.2 mL) and an increase in CSF volume (premature infants: 45.6 +/- 22.1 mL; term infants: 28.9 +/- 16 mL). The major predictors of altered cerebral volumes were gestational age at birth and the presence of cerebral WM injury. Infants with significantly reduced cortical GM and deep nuclear GM volumes and increased CSF volume volumes exhibited moderate to severe neurodevelopmental disability at 1 year of age.

CONCLUSIONS

This MRI study of prematurely born infants further defines the nature of quantitative cerebral structural abnormalities present as early as term equivalent. The abnormalities particularly involve cerebral neuronal regions including both cortex and deep nuclear structures. The pattern of cerebral alterations is related most significantly to the degree of immaturity at birth and to concomitant WM injury. The alterations are followed by abnormal short-term neurodevelopmental outcome.

Periventricular leukomalacia, inflammation and white matter lesions within the developing nervous system

Periventricular leukomalacia (PVL) occurring in premature infants, represents a major precursor for neurological and intellectual impairment, and cerebral palsy in later life. The disorder is characterized by multifocal areas of necrosis found deep in the cortical white matter, which are often symmetrical and occur adjacent to the lateral ventricles. There is no known cure for PVL. Factors predisposing to PVL include birth trauma, asphyxia and respiratory failure, cardiopulmonary defects, premature birth/low birthweight, associated immature cerebrovascular development and lack of appropriate autoregulation of cerebral blood flow in response to hypoxic-ischemic insults. The intrinsic vulnerability of oligodendrocyte precursors is considered as central to the pathogenesis of PVL. These cells are susceptible to a variety of injurious stimuli including free radicals and excitotoxicity induced by hypoxic-ischemic injury (resulting from cerebral hypoperfusion), lack of trophic stimuli, as well as secondary associated events involving microglial and astrocytic activation and the release of pro-inflammatory cytokines TNF-alpha and IL-6. It is yet unclear whether activated astrocytes and microglia act as principal participants in the development of PVL lesions, or whether they are representatives of an incidental pathological response directed towards repair of tissue injury in PVL. Nevertheless, the accumulated evidence points to a pathological contribution of microglia towards damage. The topography of lesions in PVL most likely reflects a combination of the relatively immature cerebrovasculature together with a failure in perfusion and/or hypoxia during the greatest period of vulnerability occurring around mid-to-late gestation. Mechanisms underlying the pathogenesis of PVL have so far been related to prenatal ischemic injury to the brain initiated within the third trimester, which result in global cognitive and developmental delay and motor disturbances. Over the past few years, several epidemiological and experimental studies have implicated intrauterine infection and chorioamnionitis as causative in the pathogenesis of PVL. In particular, recent investigations have shown that inflammatory responses in the fetus and neonate can contribute towards neonatal brain injury and development-related disabilities including cerebral palsy. This review presents current concepts on the pathogenesis of PVL and emphasizes the increasing evidence for an inflammatory pathogenic component to this disorder, either resulting from hypoxic-ischemic injury or from infection. These findings provide the basis for clinical approaches targeted at protecting the premature brain from inflammatory damage, which may prove beneficial for treating PVL, if identified early in pathogenesis.

Outcome of extremely low birth weight infants (500 to 999 grams) over a 12-year period

OBJECTIVE

Advances in neonatology have contributed to improved survival for extremely low birth weight (ELBW) infants. Neurodevelopmental outcome is usually reported for a single large group of infants rather than according to smaller birth weight groups because of small numbers. Our purpose was to review the neurodevelopmental outcome of a large group of ELBW infants and examine differential outcome according to birth weight.

STUDY DESIGN

A total of 446 infants born between 1979 and 1991, with a birth weight of 500 to 999 g, were followed to mean age 55 months +/- 33 standard deviation. Univariate analyses of medical risk factors of birth weight, gestational age, year of birth, growth retardation, gender, inborn/outborn status, days on oxygen, intracranial hemorrhage, and social risk in relation to outcome were conducted on the group as a whole. Neurologic/developmental outcome was also analyzed by 100-g weight groups.

RESULTS

A total of 61% of all infants were completely normal, with no neurologic, neurosensory, or cognitive deficits. There was no association between outcome and birth weight. There was a strong association between intracranial hemorrhage (ICH) grade III or IV and/or cystic periventricular leukomalacia (PVL) and abnormal outcome (Somers' D = .17) and ICH III/IV and/or cystic PVL and cognitive outcome (Kendall's tau = .15). Mild to moderate cognitive delays were associated with chronic lung disease (oxygen >60 days) (Kruskal-Wallis chi2 = 17.53) or high social risk (Kruskal-Wallis chi2 = 22.17).

CONCLUSION

In this study of ELBW infants, low birth weight was not associated with abnormal outcome. The risk factors of ICH III-IV/cystic PVL, chronic lung disease, and high social risk were associated with abnormal outcome.

Physical growth of low birthweight infants in the first year of life: impact of maternal behaviors

Physical growth of preterm infants relates to many medical factors, such as birthweight, severity of medical illnesses, and nutritional status. We previously reported that maternal behaviors influence developmental outcomes in low birthweight infants (birthweight < 1600 g); we now hypothesize that maternal behaviors also influence physical somatic growth in low birthweight (LBW) infants. We serially followed 218 mother-infant pairs from birth through 12 months of age. One-hundred thirteen LBW infants were categorized based on severity of early medical complications. Low Risk infants (LR, n = 71) had acute respiratory distress and/or grade 1-2 intraventricular hemorrhage (IVH), or grade 3 IVH without hydrocephalus. High Risk infants (HR, n = 42) had chronic lung disease, grade 3 IVH with hydrocephalus or grade 4 IVH, and/or periventricular leukomalacia. We also studied 105 socioeconomic (SES) matched Full Term (FT) controls. Maternal behaviors were assessed during home visits with global ratings of Warm Sensitivity and Punitiveness. Infant weight was measured at birth and at 38 weeks, 6 months and 12 months corrected gestational age. We examined alternative expressions of weight growth across the three groups by developing the Weight Quotient (WQ), which is the ratio of actual measured weight to the median weight for age. For each infant the regression of the WQ ratio against correct gestational age was analyzed. We used a General Linear Model to compare the relation of the maternal variables to the weight quotients for the three groups. We determined the catch up growth as the slope of each regression. Results indicated that higher levels of maternal Punitiveness were related to slower rates of growth for High Risk (R2 = 0.36), but not Low Risk or Full Term. For maternal Warm Sensitivity (R2 = 0.36), there were significant (P < 0.05) inverse relations with weight gain growth for the Full Term infants. These data suggest that some maternal behaviors are related to the growth of term and premature infants, although the mechanisms through which this occurs is unclear.

Analgesia for dying infants whose life support is withdrawn or withheld

OBJECTIVE

To determine the frequency of opiate analgesia administration to infants when life support is discontinued and to determine whether infant characteristics, such as birth weight and diagnosis, or the physician's reasons for discontinuing life support influence either the decision to provide opioid agents or the dosages administered.

METHODS

We reviewed all 165 deaths in a 3-year period at a university-based level III intensive care nursery. Of the 121 deaths attributable to withdrawal or withholding of mechanical ventilation and/or extracorporeal membrane oxygenation, we ascertained whether opioid analgesics (morphine sulfate [MS] or fentanyl) were administered either concurrent with or after life-support withdrawal and at what doses. We examined whether these end-of-life practices varied according to birth weight, diagnoses, and the reasons documented by the neonatologist for discontinuing life support.

RESULTS

Opioid analgesia was provided to 84% of infants as their life support was either withheld or withdrawn. Infants with necrotizing enterocolitis and major anomalies or chromosomal disorders were more likely to be given opiates than infants with other diagnoses. Birth weight was not different for infants who received opiates compared with those who were not given opiates. Opioid analgesia was provided to all 18 infants for whom physicians documented the patients' suffering as a reason to discontinue life support. Sixty-four percent of infants who received opiates were given doses in the usual pharmacologic range of 0.1 to 0.2 mg/kg MS. Of the 36 infants given more than 0.2 mg/kg MS, all but 2 were receiving ongoing treatment with opioid agents.

CONCLUSIONS

In most cases of withholding or withdrawal of life support in critically ill infants, neonatologists provided opioid analgesia to these infants at the end of life, despite the potential respiratory depression of opioid agents in infants whose respiratory support is discontinued.

Acute appendicitis in pregnancy and the occurrence of major intraventricular hemorrhage and periventricular leukomalacia

BACKGROUND

Infection and endotoxemia have been associated with neurologic injury in the newborn. In addition, recent reports have noted an increased incidence of fetal neurologic injury in the presence of intrauterine infection.

CASES

Three pregnancies complicated by acute appendicitis and refractory preterm labor resulting in the delivery of neonates who developed early major intraventricular hemorrhage and/or periventricular leukomalacia are described.

CONCLUSION

We hypothesize that extrauterine infections like acute appendicitis may play a role in the occurrence of neonatal neurologic injury.