Cerebral palsy in four northern California counties, births 1983 through 1985

Background suppression of electrical activity is a potential biomarker of subsequent brain injury in a rat model of neonatal hypoxia-ischemia

Electrographic seizures and abnormal background activity in the neonatal electroencephalogram (EEG) may differentiate between harmful versus benign brain insults. Using two animal models of neonatal seizures, electrical activity was recorded in freely behaving rats and examined quantitatively during successive time periods with field-potential recordings obtained shortly after the brain insult (i.e., 0-4 days). Single-channel, differential recordings with miniature wireless telemetry were used to analyze spontaneous electrographic seizures and background suppression of electrical activity after 1) hypoxia-ischemia (HI), which is a model of neonatal encephalopathy that causes acute seizures and a large brain lesion with possible development of epilepsy, 2) hypoxia alone (Ha), which causes severe acute seizures without an obvious lesion or subsequent epilepsy, and 3) sham control rats. Background EEG exhibited increases in power as a function of age in control animals. Although background electrical activity was depressed in all frequency bands immediately after HI, suppression in the β and γ bands was greatest and lasted longest. Spontaneous electrographic seizures were recorded, but only in a few HI-treated animals. Ha-treated rat pups were similar to sham controls, they had no subsequent spontaneous electrographic seizures after the treatment and background suppression was only briefly observed in one frequency band. Thus, the normal age-dependent maturation of electrical activity patterns in control animals was significantly disrupted after HI. Suppression of the background EEG observed here after HI-induced acute seizures and subsequent brain injury may be a noninvasive biomarker for detecting severe brain injuries and may help predict subsequent epilepsy.NEW & NOTEWORTHY Biomarkers of neonatal brain injury are needed. Hypoxia-ischemia (HI) in immature rat pups caused severe brain injury, which was associated with strongly suppressed background EEG. The suppression was most robust in the β and γ bands; it started immediately after the HI injury and persisted for days. Thus, background suppression may be a noninvasive biomarker for detecting severe brain injuries and may help predict subsequent epilepsy.

Pilot Study of Cadence, a Novel Shoe for Patients with Foot Drop

Foot Drop is a mobility disorder that limits ankle dorsiflexion, complicating the swing phase of gait and balance. It is a common result of a neurological injury or disease such as stroke, cerebral palsy or multiple sclerosis. Here we present Cadence, a low-cost assistive shoe designed to passively improve the biomechanics and rhythmicity of gait for people with foot drop. The shoe reduces the magnitude of scuffing forces when dragging the foot forward across the ground by using regions of low-friction material that can retract into the shoe to restore friction during stance phase. We report the results from a pilot study of Cadence, which show the biomechanical and performance effects of the device for five adults with foot drop due to neurological disorder. In 3 of the 5 subjects, we found that the shoe immediately improved gait mechanics, speed over ground, and qualitative gait comfort.

Multivariate Analysis and Machine Learning in Cerebral Palsy Research

Cerebral palsy (CP), a common pediatric movement disorder, causes the most severe physical disability in children. Early diagnosis in high-risk infants is critical for early intervention and possible early recovery. In recent years, multivariate analytic and machine learning (ML) approaches have been increasingly used in CP research. This paper aims to identify such multivariate studies and provide an overview of this relatively young field. Studies reviewed in this paper have demonstrated that multivariate analytic methods are useful in identification of risk factors, detection of CP, movement assessment for CP prediction, and outcome assessment, and ML approaches have made it possible to automatically identify movement impairments in high-risk infants. In addition, outcome predictors for surgical treatments have been identified by multivariate outcome studies. To make the multivariate and ML approaches useful in clinical settings, further research with large samples is needed to verify and improve these multivariate methods in risk factor identification, CP detection, movement assessment, and outcome evaluation or prediction. As multivariate analysis, ML and data processing technologies advance in the era of Big Data of this century, it is expected that multivariate analysis and ML will play a bigger role in improving the diagnosis and treatment of CP to reduce mortality and morbidity rates, and enhance patient care for children with CP.

Does maternal psychological distress affect neurodevelopmental outcomes of preterm infants at a gestational age of ≤32weeks

BACKGROUND

There is some evidence that maternal psychological status in the prenatal and postnatal periods is associated with infants' cognitive, behavioural, and emotional functions.

AIM

The aim of this study was to examine the relationships of maternal depression and anxiety with neurodevelopmental outcomes of preterm infants with a gestational age of ≤32weeks, examined at a corrected age of 18 to 22months.

STUDY DESIGN

Cross-sectional study.

SUBJECTS

In total, 220 preterm infants with a gestational age of ≤32weeks who were born from January 2008 to September 2011 and admitted to the neonatal intensive care unit were prospectively examined.

OUTCOME MEASURES

Neurodevelopmental evaluation was performed at a corrected age of 18 to 22months by a developmental paediatrician using the Bayley Scales of Infant Development II (BSID-II). The Beck Depression Inventory and Beck Anxiety Inventory were used to assess maternal depression and anxiety at the same visit as the neurodevelopmental evaluation.

RESULTS

The depression scores of mothers of infants with a Mental Development Index (MDI) score of <70 were significantly higher than those of mothers of infants with an MDI score of >70 (16.3±12.8 vs 8.8±7.0, p<0.001). The depression scores of mothers of infants with neurodevelopmental impairment were also significantly higher than those without neurodevelopmental impairment (12.8±10.5 vs 8.8±7.3, p=0.003). There was no relationship between the presence of cerebral palsy or a Psychomotor Developmental Index (PDI) score of <70 and the mothers' depression scores. Multiple regression analysis revealed that maternal depression and the occurrence of more than two sepsis attacks were associated with an MDI score of <70, and grade III to IV intraventricular haemorrhage was associated with neurodevelopmental impairment and a PDI score of <70.

CONCLUSION

Maternal depression is negatively associated with the neurodevelopment of preterm infants at a gestational age of ≤32weeks. Maternal psychological well-being should be taken into consideration during the long-term follow-up of preterm infants.

Prenatal Systemic Hypoxia-Ischemia and Oligodendroglia Loss in Cerebellum

Hypoxic-ischemic (HI) injury is an important cause of death and disabilities. Despite all improvements in neonatal care, the number of children who suffer some kind of injury during birth has remained stable in the last decade. A great number of studies have shown alterations in neural cells and many animal models have been proposed in the last 5 decades. Robinson et al. (2005) proposed an HI model in which the uterine arteries are temporarily clamped on the 18th gestation day. The findings were quite similar to the ones observed in postmortem studies. The white matter is clearly damaged, and a great amount of astrogliosis takes place both in the gray and white matters. Motor changes were also found but no data regarding the cerebellum, an important structure related to motor performance, was presented. Using this model, we have shown an increased level of iNOS at P0 and microgliosis and astrogliosis at P9, and astrogliosis at P23 (up to 4 weeks from the insult). NO is important in migration, maturation, and synaptic plasticity, but in exacerbated levels it may also contribute to cellular and tissue damage. We have also evaluated oligodendroglia development in the cerebellum. At P9 in HI animals, we found a decrease in the number of PDGFRα+ cells and an apparent delay in myelination, suggesting a failure in oligodendroglial progenitors migration/maturation and/or in the myelination process. These results point to an injury in cerebellar development that might help to explain the motor problems in HI.

Age specificity in general and rehabilitation medical services in children with cerebral palsy

Objective

To review the medical utilization in children with cerebral palsy according to age and discern particularities

Methods

From January 2007 to December 2007, 10,659 children and adolescents between 1 and 18 years of age who had filed national insurance claims for a diagnosis of cerebral palsy were selected. Age was chosen as an independent variable, and the population was categorized into specific age groups to verify any differences in medical service utilization. Admission duration to rehabilitation, number of visits to rehabilitation outpatient clinics, numbers of admission dates and outpatient clinic visits for general medical services, number of rehabilitation utilizations, and type of rehabilitations treatment were selected as dependent variables. One-way ANOVA was used for statistical evaluation, and analysis was done with SAS software.

Results

In general medical use, adolescences diagnosed with cerebral palsy had the highest mean admission duration (p<0.001). The mean visit day to outpatient clinics for general medical services was highest for infants (p<0.001). In rehabilitation treatment, infants diagnosed with cerebral palsy had the highest mean admission duration (p<0.001). The mean visit day to outpatient clinics for rehabilitation treatment was highest for infants (p<0.001).

Conclusion

Significant differences in use of general and rehabilitation medical services among pediatric age groups with cerebral palsy were evident. This implies that particular attention is necessary when setting up a national medical care policy for patient with cerebral palsy.

Magnesium sulfate for cerebral palsy prevention

Magnesium sulfate (MgSO4) has been shown to prevent cerebral palsy among children born to women at high risk of early preterm delivery. Three large, randomized placebo-controlled trials and a subsequent Cochrane Review suggest this intervention can decrease rates of cerebral palsy by 32% with a number needed to treat of 63 to prevent one case. Not only is MgSO4 familiar to obstetricians, it also has an excellent safety profile. Simple protocols exist to help guide clinicians in using MgSO4 for this indication. Evaluation of actual clinical practice shows that this use is both feasible and can be accomplished parsimoniously.

Nanomedicine in cerebral palsy

Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed.

A systematic review of risk factors for cerebral palsy in children born at term in developed countries

AIM

The aim of this study was to conduct a systematic review in order to identify the risk factors for cerebral palsy (CP) in children born at term. The secondary aim was to ascertain if the potential for prevention of these risk factors has been adequately explored.

METHOD

A MEDLINE search up to 31 July 2011 was completed, following the Meta-Analysis of Observational Studies in Epidemiology guidelines. Publications were reviewed to identify those with both a primary aim of identifying risk factors for all children or term-born children with CP and a cohort or case-control study design. Studies were examined for potential chance or systematic bias. The range of point estimates of relative risk is reported.

RESULTS

From 21 articles meeting inclusion/exclusion criteria and at low risk of bias, data from 6297 children with CP and 3 804 791 children without CP were extracted. Ten risk factors for term-born infants were statistically significant in each study: placental abnormalities, major and minor birth defects, low birthweight, meconium aspiration, instrumental/emergency Caesarean delivery, birth asphyxia, neonatal seizures, respiratory distress syndrome, hypoglycaemia, and neonatal infections. Strategies for possible prevention currently exist for three of these.

INTERPRETATION

Ten consistent risk factors have been identified, some with potential for prevention. Efforts to prevent these risk factors to interrupt the pathway to CP should be extended.

Evaluation of the clinical use of magnesium sulfate for cerebral palsy prevention

OBJECTIVE

Clinical trials support the efficacy and safety of magnesium sulfate for cerebral palsy prevention. We evaluated the implementation of a clinical protocol for the use of magnesium for cerebral palsy prevention in our large women's hospital, focusing on uptake, indications, and safety.

METHODS

We performed a review of selected gravidas with threatened or planned delivery before 32 weeks of gestation from October 2007 to February 2011. The primary study outcome was the change in the rate of predelivery administration of magnesium sulfate over this time period.

RESULTS

Three hundred seventy-three patients were included. In 2007, before guideline implementation, 20% of eligible gravidas (95% confidence interval [CI] 9.1-35.6%) received magnesium before delivery compared with 93.9% (95% CI 79.8-99.3%) in the final 2 months of the study period (P<.001). Dosing did not vary significantly over the 4 study years: the median number of treatments was one, the total predelivery median dose ranged from 15 to 48 g, and the median duration of therapy ranged from 3 to 12 hours. After 3 years, magnesium administration was almost universal among patients diagnosed with preeclampsia, preterm labor, or preterm premature rupture of membranes (95.4%), whereas patients delivered preterm for fetal growth restriction were significantly less likely to receive predelivery magnesium (44%, P<.001). No maternal or perinatal magnesium-attributable morbidity was noted. Among patients eligible for the protocol who received magnesium, 84.2% delivered before 32 weeks of gestation.

CONCLUSION

It is feasible to implement a magnesium sulfate cerebral palsy prevention protocol into clinical practice.

LEVEL OF EVIDENCE

III.

Prophylactic maternal N-acetylcysteine in rats prevents maternal inflammation-induced offspring cerebral injury shown on magnetic resonance imaging

OBJECTIVE

Maternal infection or inflammation may induce fetal inflammatory responses associated with fetal injury and cerebral palsy. We sought to assess the inflammation-associated neuroprotective potential of prophylactic N-acetyl-cysteine (NAC). We examined the effect of NAC on prevention of maternal lipopolysaccharide (LPS)-induced neonatal brain injury using magnetic resonance imaging.

STUDY DESIGN

Pregnant Sprague Dawley dams (n = 5-8) at embryonic day 18 received intraperitoneal injection of LPS or saline at time 0. Animals were randomized to receive 2 intravenous injections of NAC or saline (time -30 and 120 minutes). Pups were delivered spontaneously and allowed to mature until postnatal day 25. Female offspring were examined by magnetic resonance brain imaging and analyzed using voxel-based analysis after spatial normalization. T2 relaxation time was used to assess white matter injury and diffusion tensor imaging for apparent diffusion coefficient (ADC) to assess white and gray matter injury.

RESULTS

Offspring of LPS-treated dams exhibited significantly increased T2 levels and increased ADC levels in white and gray matter (eg, hypothalamus, motor cortex, corpus callosum, thalamus, hippocampus), consistent with diffuse cerebral injury. In contrast, offspring of NAC-treated LPS dams demonstrated similar T2 and ADC levels as control in both white and gray matter.

CONCLUSION

Maternal NAC treatment significantly reduced evidence of neonatal brain injury associated with maternal LPS. These studies suggest that maternal NAC therapy may be effective in human deliveries associated with maternal/fetal inflammation.

Recording EEG in immature rats with a novel miniature telemetry system

Serial EEG recordings from immature rat pups are extremely difficult to obtain but important for analyzing animal models of neonatal seizures and other pediatric neurological conditions as well as normal physiology. In this report, we describe the features and applications of a novel miniature telemetry system designed to record EEG in rat pups as young as postnatal day 6 (P6). First, we have recorded electrographic seizure activity in two animal models of neonatal seizures, hypoxia- and kainate-induced seizures at P7. Second, we describe a viable approach for long-term continuous EEG monitoring of naturally reared rat pups implanted with EEG at P6. Third, we have used serial EEG recordings to record age-dependent changes in the background EEG signal as the animals matured from P7 to P11. The important advantages of using miniature wireless EEG technology are: 1) minimally invasive surgical implantation; 2) a device form-factor that is compatible with housing of rat pups with the dam and littermates; 3) serial recordings of EEG activity; and 4) low power consumption of the unit, theoretically allowing continuous monitoring for up to 2 yr without surgical reimplantation. The miniature EEG telemetry system provides a technical advance that allows researchers to record continuous and serial EEG recordings in neonatal rodent models of human neurological disorders, study the progression of the disease, and then assess possible therapies using quantitative EEG as an outcome measure. This new technical approach should improve animal models of human conditions that rely on EEG monitoring for diagnosis and therapy.

Neuroprotective approaches: before and after delivery

Infants born preterm are especially vulnerable to cerebral palsy, the risk of which is inversely proportional to gestational age at birth. The contribution of prematurity to the overall burden of cerebral palsy is substantial. This article reviews and discusses potential antenatal and postnatal neuroprotective approaches targeted at the numerous risk factors associated with cerebral palsy among preterm infants, including magnesium sulfate.

Epidemiology of cerebral palsy in El-Kharga District-New Valley (Egypt)

Cerebral palsy (CP) is the most frequent cause of motor handicap among children. The present door to door (every door) study was conducted in El-Kharga District-New Valley to estimate the epidemiology of CP among children. Each child was subjected to complete medical and neurological examination to detect cases with CP. These diseased children were subjected to meticulous neurological and medical assessment, brain MRI, EEG and Stanford Binet (4th edition). It was found that 52 out of 25,540 children had CP yielding prevalence rate of 2.04/1000 (95% CI: 1.48-2.59) of living births. Mean age of children with CP, was 7.17±4.38years. The order of frequency of different subtypes of CP was as follows, 65.4% had spastic type, 26.9% mixed type and 3.8% for each ataxic and dyskinetic types of CP. The frequency of risk factors of CP in our study is prenatal complications (cyanosis, preterm, jaundice, birth weight and obstructed labor of mothers), first baby, similar condition and recurrent abortions.

Treadmill responses and physical activity levels of infants at risk for neuromotor delay

PURPOSE

This study described developmental changes in treadmill (TM) stepping and physical activity (PA) of infants at risk for neuromotor delay (ND) and explored these changes by diagnosis of cerebral palsy (CP). Relationships of stepping and PA with walking onset were examined.

METHOD

Fifteen infants at risk for ND (9.9 +/- 2.4 months) were tested every 2 months on a TM until walking onset or 24 months of corrected age. We recorded PA profiles using an activity monitor. Throughout the study, 6 of the 15 infants received a CP diagnosis.

RESULTS

Infants increased alternating steps (AltStp), decreased toe contacts, and increased high-level PA. Infants with CP showed less AltStp, more toe contacts, and less high-level PA than those without CP. Infants' AltStp and high-level PA revealed a positive correlation to earlier onset of walking.

CONCLUSION

Future studies should examine whether a TM intervention could improve mobility in infants at risk for ND.

Heart rate characteristics and neurodevelopmental outcome in very low birth weight infants

BACKGROUND

Sepsis in very low birth weight (VLBW) infants has been associated with an increased risk of adverse developmental outcome. We have identified abnormal heart rate characteristics (HRCs) that are predictive of impending sepsis, and we have developed a summary measure of an infant's abnormal HRCs during the neonatal hospitalization that we refer to as the cumulative HRC score (cHRC).

OBJECTIVE

In this study, we tested the hypothesis that increasing cHRC is associated with an increasing risk of adverse neurodevelopmental outcome in VLBW infants.

METHOD

Data were collected on 65 VLBW infants whose HRCs were monitored while in the neonatal intensive care unit and who were examined at 12 to 18 months adjusted age. Using the Bayley Scale of Infant Development-II, we identified delays in early cognitive function (i.e., Mental Developmental Index <70) and psychomotor development (i.e., Psychomotor Developmental Index <70). Cerebral palsy (CP) was diagnosed using a standard neurological examination.

RESULT

Increasing cHRC score was associated with an increased risk of CP (odds ratio per 1 standard deviation increase in cHRC: 2.6, 95% confidence limits: 1.42, 5.1) and delayed early cognitive development [odds ratio: 2.3 (1.3; 4.3)]. These associations remain statistically significant when adjusted for major cranial ultrasound abnormality. There was an association of increasing cHRC and delayed psychomotor development, which did not reach statistical significance [odds ratio: 1.7 (1.0, 3.0)].

CONCLUSION

Among VLBW infants, the cumulative frequency of abnormal HRCs, which can be assessed non-invasively in the neonatal intensive care unit, is associated with an increased risk of adverse neurodevelopmental outcome.

The role of perinatal and intrapartum risk factors in the etiologyof cerebral palsy in term deliveries in a Turkish population

OBJECTIVE

To investigate the relationship between cerebral palsy (CP) and perinatal and intrapartum risk factors and markers of birth asphyxia.

METHODS

This was a retrospective case-control study of 101 children with CP and 308 controls who were born at the Zeynep Kamil Hospital between 1990 and 2000. The roles of possible perinatal and intrapartum risk factors were investigated in CP development. Chi-square tests, Fisher's exact tests, Student t-tests, and regression analysis were used for statistical analysis (p < 0.05).

RESULTS

The only significant perinatal risk factor was neonatal weight of <2500 grams. The CP rate in the presence of solely intrapartum risk factors was estimated as 24.7% (n = 25). In 39.6% of cases, no risk factor could be identified. When regression analysis was performed, the following factors were significant: decreased beat-to-beat variability on electronic fetal monitoring (EFM) (p = 0.02), an Apgar score of <7 at 1 and 5 minutes (p = 0.02), and the necessity for neonatal intensive care unit admission (p < 0.0001).

CONCLUSION

Intrapartum risk factors were significantly more frequent in the CP group (p < 0.01). An increased cesarean section rate could not prevent CP, suggesting that the hypoxic insult that causes CP might be of chronic onset. The development of diagnostic tests to detect non-reassuring fetal status in its intrauterine life and interventions at appropriate times may decrease the CP rate.

Role of perinatal inflammation in cerebral palsy

Inflammatory molecules are promptly upregulated in the fetal environment and postnatally in brain-damaged subjects. Intrauterine infections and inflammation are often associated with asphyxia. This double-hit effect by combined infection or inflammation and hypoxia is therefore a frequent concomitant in neonatal brain damage. Animal models combining hypoxia and infection were recently designed to explore the mechanisms underlying brain damage in such circumstances and to look for possible neuroprotective strategies. Proinflammatory cytokines are thought to be major mediators in brain injury in neonates with perinatal asphyxia, bacterial infection, or both. Cytokines, however, could also have neuroprotective properties. The critical point in the balance between neurodamaging and neuroprotective effects of cytokines has yet to be unraveled. This understanding might help to develop new therapeutic approaches to counteract the inflammatory disequilibrium observed in the pathophysiologic mechanisms associated with brain injury.

Increased risk of adverse neurological development for late preterm infants

OBJECTIVE

To assess the risks of moderate prematurity for cerebral palsy (CP), developmental delay/mental retardation (DD/MR), and seizure disorders in early childhood.

STUDY DESIGN

Retrospective cohort study using hospitalization and outpatient databases from the Northern California Kaiser Permanente Medical Care Program. Data covered 141 321 children > or =30 weeks born between Jan 1, 2000, and June 30, 2004, with follow-up through June 30, 2005. Presence of CP, DD/MR, and seizures was based on International Classification of Diseases, Ninth Revision codes identified in the encounter data. Separate Cox proportional hazard models were used for each of the outcomes, with crude and adjusted hazard ratios calculated for each gestational age group.

RESULTS

Decreasing gestational age was associated with increased incidence of CP and DD/MR, even for those born at 34 to 36 weeks gestation. Children born late preterm were >3 times as likely (hazard ratio, 3.39; 95% CI, 2.54-4.52) as children born at term to be diagnosed with CP. A modest association with DD/MR was found for children born at 34 to 36 weeks (hazard ratio, 1.25; 95% CI, 1.01-1.54), but not for children in whom seizures were diagnosed.

CONCLUSIONS

Prematurity is associated with long-term neurodevelopmental consequences, with risks increasing as gestation decreases, even in infants born at 34 to 36 weeks.

A randomized, controlled trial of magnesium sulfate for the prevention of cerebral palsy

BACKGROUND

Research suggests that fetal exposure to magnesium sulfate before preterm birth might reduce the risk of cerebral palsy.

METHODS

In this multicenter, placebo-controlled, double-blind trial, we randomly assigned women at imminent risk for delivery between 24 and 31 weeks of gestation to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour, or matching placebo. The primary outcome was the composite of stillbirth or infant death by 1 year of corrected age or moderate or severe cerebral palsy at or beyond 2 years of corrected age.

RESULTS

A total of 2241 women underwent randomization. The baseline characteristics were similar in the two groups. Follow-up was achieved for 95.6% of the children. The rate of the primary outcome was not significantly different in the magnesium sulfate group and the placebo group (11.3% and 11.7%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.77 to 1.23). However, in a prespecified secondary analysis, moderate or severe cerebral palsy occurred significantly less frequently in the magnesium sulfate group (1.9% vs. 3.5%; relative risk, 0.55; 95% CI, 0.32 to 0.95). The risk of death did not differ significantly between the groups (9.5% vs. 8.5%; relative risk, 1.12; 95% CI, 0.85 to 1.47). No woman had a life-threatening event.

CONCLUSIONS

Fetal exposure to magnesium sulfate before anticipated early preterm delivery did not reduce the combined risk of moderate or severe cerebral palsy or death, although the rate of cerebral palsy was reduced among survivors. (ClinicalTrials.gov number, NCT00014989.)

White matter injury correlates with hypertonia in an animal model of cerebral palsy

Hypertonia and postural deficits are observed in cerebral palsy and similar abnormalities are observed in postnatal rabbits after antenatal hypoxia-ischemia. To explain why some kits become hypertonic, we hypothesized that white matter injury was responsible for the hypertonia. We compared newborn kits at postnatal day 1 (P1) with and without hypertonia after in vivo global fetal hypoxia-ischemia in pregnant rabbits at 70% gestation. The aim was to examine white matter injury by diffusion tensor magnetic resonance imaging indices, including fractional anisotropy (FA). At P1, FA and area of white matter were significantly lower in corpus callosum, internal capsule, and corona radiata of the hypertonic kits (n=32) than that of controls (n=19) while nonhypertonic kits (n=20) were not different from controls. The decrease in FA correlated with decrease in area only in hypertonia. A threshold of FA combined with area identified only hypertonic kits. A reduction in volume and loss of phosphorylated neurofilaments in corpus callosum and internal capsule were observed on immunostaining. Concomitant hypertonia with ventriculomegaly resulted in a further decrease of FA from P1 to P5 while those without ventriculomegaly had a similar increase of FA as controls. Thus, hypertonia is associated with white matter injury, and a population of hypertonia can be identified by magnetic resonance imaging variables. The white matter injury manifests as a decrease in the number and density of fiber tracts causing the decrease in FA and volume. Furthermore, the dynamic response of FA may be a good indicator of the plasticity and repair of the postnatal developing brain.

Cerebral palsy and fetal inflammatory response syndrome: a review

Cerebral palsy (CP) is the most common cause of severe physical disability in childhood. The precise etiological factor for the development of the majority of cases of CP has not been identified, however, prematurity is considered to be the leading identifiable risk factor. During the last decade, intrauterine infection/inflammation has been identified as the most common cause of preterm delivery and neonatal complications. When microorganisms or their products gain access to the fetus they stimulate the production of cytokines and a systemic response termed FIRS (Fetal Inflammatory Response Syndrome). Subsequently, FIRS was implicated as a cause of fetal or neonatal injury that leads to CP and chronic lung disease. Several authors found an increase in the risk for CP in infants born to mothers with clinical chorioamnionitis, especially in preterm neonates. A relationship between CP and intra-amniotic inflammation was demonstrated, intrauterine infection may lead to activation of the cytokine network which in turn can cause white matter brain damage and preterm delivery, as well as the future development of CP. This white matter insult is identified clinically as periventricular leucomalacia (PVL) which is associated with the subsequent development of impaired neurological outcomes of variable severity including CP.

Cerebral palsy in a term population: risk factors and neuroimaging findings

OBJECTIVE

The purpose of this work was to study risk factors and neuroimaging characteristics of cerebral palsy in term and near-term infants.

PATIENTS AND METHODS

Among a cohort of 334,339 infants > or = 36 weeks' gestation born at Kaiser Permanente Medical Care Program in northern California in 1991-2003, we identified infants with cerebral palsy and obtained clinical data from electronic and medical charts. Risk factors for cerebral palsy among infants with different brain abnormalities were compared using polytomous logistic regression.

RESULTS

Of 377 infants with cerebral palsy (prevalence: 1.1 per 1000), 273 (72%) received a head computed tomography or MRI. Abnormalities included focal arterial infarction (22%), brain malformation (14%), and periventricular white matter abnormalities (12%). Independent risk factors for cerebral palsy were maternal age > 35, black race, and intrauterine growth restriction. Intrauterine growth restriction was more strongly associated with periventricular white matter injury than with other neuroimaging findings. Nighttime delivery was associated with cerebral palsy accompanied by generalized brain atrophy but not with cerebral palsy accompanied by other brain lesions.

CONCLUSIONS

Cerebral palsy is a heterogeneous syndrome with focal arterial infarction and brain malformation representing the most common neuroimaging abnormalities in term and near-term infants. Risk factors for cerebral palsy differ depending on the type of underlying brain abnormality.

Estimación de la prevalencia de parálisis cerebral en la comunidad de Castilla y León mediante el registro de minusvalías

INTRODUCTION

The prevalence of cerebral palsy in Western countries is estimated to be around 2 cases/1,000 inhabitants. The objective of this study was to estimate the prevalence of cerebral palsy in the Autonomous Community of Castilla y León and to assess potential differences among the nine provinces of this region.

PATIENTS AND METHODS

The number of patients with CP in 1999, separated by provinces and by age groups, was obtained from the Community Sectorial Program for Persons with Disabilities. These data originally came from handicap evaluations carried out in each base center. Prevalences were calculated using population data from the National Institute of Statistics.

RESULTS

A total of 335 patients aged 0-13 years were registered as having a diagnosis of cerebral palsy in 1999. The prevalence of cerebral palsy was 1.05 cases/1,000 inhabitants aged 0-13 years. Statistically significant differences were found in the prevalence of cerebral palsy among provinces (p < 0.0001). The highest prevalence was found in Salamanca, with 1.87 cases/1,000 inhabitants, while the lowest prevalence was found in Segovia, with 0.33 cases/ 1,000 inhabitants.

CONCLUSIONS

The prevalence of cerebral palsy in childhood in Castilla y León was lower than that reported in western countries. Substantial differences were found among provinces. The prevalence of cerebral palsy is probably underreported in some provinces. These differences could be due to a disparity in diagnostic criteria, especially in young children.

Unstudied infants: outcomes of moderately premature infants in the neonatal intensive care unit

BACKGROUND

Newborns of 30-34 weeks gestation comprise 3.9% of all live births in the United States and 32% of all premature infants. They have been studied much less than very low birthweight infants.

OBJECTIVE

To measure in-hospital outcomes and readmission within three months of discharge of moderately premature infants.

DESIGN

Prospective cohort study including retrospective chart review and telephone interviews after discharge.

SETTING

Ten birth hospitals in California and Massachusetts.

PATIENTS

Surviving moderately premature infants born between October 2001 and February 2003.

MAIN OUTCOME MEASURES

(a) Occurrence of assisted ventilation during the hospital stay after birth; (b) adverse in-hospital outcomes-for example, necrotising enterocolitis; (c) readmission within three months of discharge.

RESULTS

With the use of prospective cluster sampling, 850 eligible infants and their families were identified, randomly selected, and enrolled. A total of 677 families completed a telephone interview three months after hospital discharge. During the birth stay, these babies experienced substantial morbidity: 45.7% experienced assisted ventilation, and 3.2% still required supplemental oxygen at 36 weeks. Readmission within three months occurred in 11.2% of the cohort and was higher among male infants and those with chronic lung disease.

CONCLUSIONS

Moderately premature infants experience significant morbidity, as evidenced by high rates of assisted ventilation, use of oxygen at 36 weeks, and readmission. Such morbidity deserves more research.

The descriptive epidemiology of cerebral palsy

The prevalence of cerebral palsy (CP) ranges from 1.5 to 2.5 per 1000 live births with little or no variation among western nations, although data from the Americas are sparse. Time trends in overall CP prevalence for the past 40 years are most notable for their stability, but a modest increase in prevalence probably occurred in the last decades of the twentieth century. European countries have pioneered the development of CP registries, and as a result, CP is a condition that is enumerated regularly in several parts of the world. The United States has no CP registries, although ongoing surveillance of CP, along with other developmental disabilities, is performed by the Centers for Disease Control and Prevention in metropolitan Atlanta.

Short-term outcomes of infants born at 35 and 36 weeks gestation: we need to ask more questions

BACKGROUND

Newborns who are 35 to 36 weeks gestation comprise 7.0% of all live births and 58.3% of all premature infants in the United States. They have been studied much less than very low birth weight infants.

OBJECTIVE

To examine available data permitting quantification of short-term hospital outcomes among infants born at 35 and 36 weeks gestation.

DESIGN

Review of existing published data and, where possible, re-analysis of existing databases or retrospective cohort analyses.

SETTING

Multiple hospitals and neonatal intensive care units in the United States and England.

PATIENTS

Premature infant cohorts with infants whose dates of birth ranged from 1/1/98 through 6/30/04.

MAIN OUTCOME MEASURES

1) Death, 2) respiratory distress requiring some degree of in-hospital respiratory support during the birth hospitalization, and 3) rehospitalization following discharge home after the birth hospitalization.

RESULTS

Newborns born at 35 and 36 weeks gestation experienced considerable mortality and morbidity. Approximately 8% required supplemental oxygen support for at least 1 hour, almost 3 times the rate found in infants born at > or =37 weeks. Among 35 to 36 week newborns who progressed to respiratory failure and who survived to 6 hours of age and did not have major congenital anomalies, the mortality rate was 0.8%. Following discharge from the birth hospitalization, 35 to 36 week infants were much more likely to be rehospitalized than term infants, and this increase was evident both within 14 days as well as within 15 to 182 days after discharge. In addition, late preterm infants experienced multiple therapies, few of which have been formally evaluated for safety or efficacy in this gestational age group.

CONCLUSIONS

Greater attention needs to be paid to the management of late preterm infants. In addition, it is important to conduct formal evaluations of the therapies and follow-up strategies employed in caring for these infants.

Developmental changes induced by graded prenatal systemic hypoxic–ischemic insults in rats

In infants, a common consequence of systemic perinatal insults is disruption of neonatal brain development. Such insults can cause cerebral palsy, cognitive delay, epilepsy and other chronic neurologic deficits in children. The mechanisms underlying disruption of brain development after perinatal insults are poorly defined. To mimic human systemic insults, a transient prenatal hypoxic-ischemic insult model was developed in rodents. Ischemic animals showed reproducible histological lesions including oligodendrocyte loss, gliosis, and axonal disruption. Ischemic animals displayed persistent postnatal loss of oligodendrocyte lineage cells and cortical neurons, decreased cell proliferation, increased cell death, elevated pro-inflammatory cytokine levels, and impaired motor skills as young adults. Progressive ischemic intervals produced a graded pattern of injury. This systemic rodent prenatal hypoxic-ischemic insult accurately models human perinatal brain injury in several important criteria, including functional association of altered brain development with motor delay, and consequently provides novel insights into the pathogenesis of human perinatal brain insults.

Global and Specific Behavioral Measures of Pain in Children With Cerebral Palsy

OBJECTIVES

The aim of this research was to validate global and behavioral observation methods for measuring pain in children with cerebral palsy (CP).

MATERIALS AND METHODS

Nineteen children diagnosed with CP (2-21 years of age) and their primary caregivers participated in this study. Children and their caregivers were videotaped in their home before, during, and after a stretching exercise, and tests of cognitive and social development were administered. Children who were able to pass a training task were also asked to rate their experience of pain using a numerical rating scale (self-report NRS), but only 5 children (24%) passed so their self-report scores were not included. Healthcare professionals rated videotaped segments for each of the 3 time periods in a randomized order using an observer NRS and the Non-Communicating Children's Pain Checklist-Postoperative Version (NCCPC-PV). Raters trained in the Child Facial Coding System (CFCS) examined the same videotaped segments.

RESULTS

Results showed significantly greater pain behavior (observer NRS, NCCP- PV) during the stretching procedure than during the baseline and recovery segments. There were no significant differences in CFCS scores, across time segments.

CONCLUSIONS

These findings support the hypothesis that children with CP express discernible pain behaviors regardless of cognitive or language ability. These results contribute to multidimensional assessment of pain in children with neurologic impairment.

Maternal infection and risk of cerebral palsy in term and preterm infants

OBJECTIVE

We tested the hypothesis that term and preterm infants exposed to maternal infection at the time of delivery are at increased risk of developing cerebral palsy (CP).

STUDY DESIGN

A population-based case-control study was conducted using Washington State birth certificate data linked to hospital discharge data. Cases (688) were children <or=6 years old, singleton births, hospitalized during 1987 to 1999 with an ICD-9 diagnosis code for CP. Controls were 3,068 singleton birth infants randomly selected from birth records for the same years without CP-related hospitalizations. Infection information was available only for the birth hospitalization.

RESULTS

Infants of women who had any infection during their hospitalization for delivery were at increased risk of CP (odds ratio (OR) 3.1, 95% confidence interval (CI) 2.3 to 4.2). This was observed for term deliveries (OR 1.8, 95% CI 1.1 to 2.8) and preterm deliveries (OR 2.3, 95% CI 1.3 to 4.2).

CONCLUSIONS

Our results suggest that maternal infection is a risk factor for CP in both term and preterm infants.

Risks for severe mental retardation occurring in isolation and with other developmental disabilities

Individual and maternal characteristics as potential risk factors for having severe mental retardation (SMR) occurring with and without cerebral palsy (CP), epilepsy, or a pervasive developmental disorder (PDD) were explored among a cohort of 119,404 children without Down syndrome born in the California Central Valley in 1992 and 1993. Unadjusted and adjusted relative risks (RRs) and their 95% confidence intervals (CIs) based on the Poisson distribution were used to estimate the risks associated with each individual and maternal factor studied for each SMR diagnostic category. The most notable increased risks for SMR occurring in isolation or with CP or epilepsy was for children born low-birth-weight or preterm who were at a substantially increased risk (RRs 2.6-9.9). In contrast, the risk of SMR occurring with a PDD was the greatest among males compared to females (RR = 3.4, 95% CI 1.5, 7.9), Blacks compared to Whites (RR = 5.1, 95% CI 1.7, 15.5), and Asians compared to Whites (RR = 3.9, 95% CI 1.3, 12.0). Etiologic heterogeneity when SMR occurs with a PDD was suggested.

Cerebral palsy registries

Cerebral palsy (CP) registers appear to be appropriate tools for answering questions regarding the prevalence and characteristics of this common childhood disability. Registers are population databases issuing from multiple sources, relying on a clear definition and inclusion and exclusion criteria of CP, and requiring a mix of skills with the collaboration of obstetricians, pediatricians, and epidemiologists. In Europe alone there are 18 different CP registers or population data collections on CP, and collaborative research efforts exist through a European network. Data collection on CP has also been done in Australia (register), the United States (surveys), and Canada (register). Beside monitoring trends, other public health contributions of CP registers might be to reduce the frequency of CP and to improve the quality of life of children with CP. CP registers are useful to clinicians by enabling them to identify subgroups of children requiring specific etiologic investigations, and also to provide more accurate information to the parents of children with CP.

Animal models of hypoxic-ischemic brain damage in the newborn

Controversy continues over which animal model to use as a reflection of human disease states. With respect to perinatal brain disorders, scientists must contend with a disease in evolution. In that regard, the perinatal brain is at risk during a time of extremely rapid development and maturation, involving processes that are required for normal growth. Interfering with these processes, as part of therapeutic intervention must be efficacious and safe. To date, numerous models have provided tremendous information regarding the pathophysiology of brain damage to term and preterm infants. Our challenges will continue to be in identifying those infants at greatest risk for permanent injury, and adapting therapies that provide more benefit than harm. Using animal models to conduct these studies will bring us closer to that goal.

Preterm fetal hypoxia-ischemia causes hypertonia and motor deficits in the neonatal rabbit: a model for human cerebral palsy?

Prenatal hypoxia-ischemia to the developing brain has been strongly implicated in the subsequent development of the hypertonic motor deficits of cerebral palsy (CP) in premature and full-term infants who present with neonatal encephalopathy. Despite the enormous impact of CP, there is no animal model that reproduces the hypertonia and motor disturbances of this disorder. We report a rabbit model of in utero placental insufficiency, in which hypertonia is accompanied by marked abnormalities in motor control. Preterm fetuses (67-70% gestation) were subjected to sustained global hypoxia. The dams survived and gave spontaneous birth. At postnatal day 1, the pups that survived were subjected to a battery of neurobehavioral tests developed specifically for these animals, and the tests were videotaped and scored in a masked manner. Newborn pups of hypoxic groups displayed significant impairment in multiple tests of spontaneous locomotion, reflex motor activity, and the coordination of suck and swallow. Increased tone of the limbs at rest and with active flexion and extension were observed in the survivors of the preterm insult. Histopathological studies identified a distinct pattern of acute injury to subcortical motor pathways that involved the basal ganglia and thalamus. Persistent injury to the caudate putamen and thalamus at P1 was significantly correlated with hypertonic motor deficits in the hypoxic group. Antenatal hypoxia-ischemia at preterm gestation results in hypertonia and abnormalities in motor control. These findings provide a unique behavioral model to define mechanisms and sequelae of perinatal brain injury from antenatal hypoxia-ischemia.

Neurodevelopmental Disabilities

The topic of this chapter is neurodevelopmental disabilities, with discussion focused on three prototypic neurodevelopmental disorders: mental retardation, autism, and cerebral palsy. These disorders are highlighted because the epidemiologic knowledge is more advanced; however, many of the important methodologic issues apply to other neurodevelopmental disorders. The chapter discusses the particular research challenges in achieving complete case ascertainment due to the problems of case finding and case confirmation. It presents information about the prevalence of each of these disorders and temporal changes in frequency over time, as well as the possible factors contributing to increased recognition of these disorders. The chapter summarizes investigations of risk factors for each disorder, including genetic factors and possible environmental etiologies.

Unselected low-risk pregnancies and the effect of continuous intrapartum fetal heart rate monitoring on umbilical blood gases and cerebral palsy

OBJECTIVE

Our purpose was to evaluate the clinical validity of electronic fetal heart rate monitoring to detect fetal acidemia and to evaluate the prevalence of cerebral palsy in unselected low-risk pregnancies.

STUDY DESIGN

We selected two secondary and two tertiary level institutions in which 10,030 infants were born. Among them, 5546 of the pregnancies were low-risk pregnancies by antepartum evaluation. The fetal heart rate patterns were interpreted according to the guidelines of the National Institute of Child Health and Human Development. The correlations between the fetal heart rate pattern and umbilical blood gases and the fetal heart rate pattern and cerebral palsy were studied. Spastic cerebral palsy was diagnosed at > or =1 year by pediatric neurologists. Statistics included unpaired t test, contingency table with chi(2) and Fisher tests, and one-way analysis of variance with Bonferroni/Dunn test.

RESULTS

On the basis of the severity of decelerations, frequency of decelerations, and decreased variability, umbilical pH, and Po(2) level were decreased accordingly, and incidence of pH<7.1 was increased. Sensitivity and false-positive rate of nonreassuring fetal heart rate patterns for fetal acidemia were 63% and 89%. There were nine cerebral palsy cases: six of the cases were preexisting asphyxia before monitoring was initiated, two of the cases were cytomegaloviral infections, and one of the cases was a maternal amniotic fluid embolism.

CONCLUSION

In low-risk pregnancies, intrapartum fetal heart rate monitoring was useful to detect fetal acidemia. Cerebral palsy caused by intrapartum asphyxia was restricted to unavoidable accidents under continuous fetal heart rate monitoring.

Infants with bilirubin levels of 30 mg/dL or more in a large managed care organization

OBJECTIVE

To describe the incidence, etiology, treatment, and outcome of newborns with total serum bilirubin (TSB) levels >or=30 mg/dL (513 micro mol/L).

DESIGN

Population-based case series.

SETTING

Eleven Northern California Kaiser Permanente Medical Care Program hospitals and 1 affiliated hospital.

PATIENTS

Eleven infants with TSB levels of >or=30 mg/dL in the first 30 days after birth, identified using computer databases from a cohort of 111,009 infants born 1995-1998.

OUTCOME MEASURES

Clinical data from the birth hospitalization, rehospitalization, and outpatient visits in all infants; psychometric testing at age 5 (N = 3), neurologic examinations by child neurologists at age 5 (N = 3), or primary care providers (N = 7; mean age: 2.2 years); Parent Evaluation of Developmental Status (N = 8; mean age: 4.2 years).

RESULTS

Maximum TSB levels of the 11 infants ranged from 30.7 to 45.5 mg/dL (525 micro mol/L to 778 micro mol/L; mean: 34.9 mg/dL [597 micro mol/L]). Four were born at 35 to 36 weeks gestation, and 7 were exclusively breastfed. Two had apparent isoimmunization; the etiology for the other 9 remained obscure, although only 4 were tested for glucose-6-phosphate dehydrogenase deficiency and 1 was bacteremic. None had acute neurologic symptoms. All received phototherapy and 5 received exchange transfusions. One infant died of sudden infant death syndrome; there was no kernicterus at autopsy. Two were lost to follow-up but were neurologically normal when last seen for checkups at 18 and 43 months. One child was receiving speech therapy at age 3. There were no significant parental concerns or abnormalities in the other children.

CONCLUSIONS

In this setting, TSB levels >or=30 mg/dL were rare and generally unaccompanied by acute symptoms. Although we did not observe serious neurodevelopmental sequelae in this small sample, additional studies are required to quantify the known, significant risk of kernicterus in infants with very high TSB levels.

Macropremies: underprivileged newborns

The focus of neonatal intensive care has been on very low birthweight infants, who comprise only 1.4% of neonates. Too little attention is paid to moderately preterm infants that we call macropremies or moderately low birthweight infants (MLBW, with birthweights 1500-2500 grams). Admitting over half MLBW infants to normal nurseries presumes that they have few needs and an excellent prognosis similar to fullterm newborns. It does not take into account the macropremie's vulnerability to complications of prematurity due to immature organ systems. Obstetricians are increasingly willing to deliver these infants prematurely for signs of fetal distress. As many as 25% of children with cerebral palsy referred to a disability clinic in Paris were MLBW, with hypoxic-ischemic-inflammatory associated disorders in one-third. The majority of MLBW infants who required neonatal intensive care at a tertiary care center in Baltimore had complications of prematurity: 47% had respiratory problems, 20% had feeding intolerance and 9% had hypoglycemia. MLBW infants comprise 5-7% of the neonatal population but account for 14% of neonatal deaths, 18-37% of children with cerebral palsy and 7-12% of children with mental retardation. Increasing the level of neonatal care for the macropremie's transition to extrauterine life would be economically feasible if it prevented as few as 30% of cases of major disability. A change in attitude towards this low risk (but not risk free) group of MLBW infants will both reduce morbidity and improve their health and neurodevelopmental outcome. It includes: 1) Providing an intermediate level of neonatal care for a short duration, with close monitoring and prompt intervention as needed, and 2) Neonatal neurodevelopmental screening to allow focused neurodevelopmental followup of MLBW infants with abnormalities.