Effect of erythropoietin combined with hypothermia on serum tau protein levels and neurodevelopmental outcome in neonates with hypoxic-ischemic encephalopathy

Although hypothermia therapy is effective to treat neonatal hypoxic-ischemic encephalopathy, many neonatal patients die or suffer from severe neurological dysfunction. Erythropoietin is considered one of the most promising neuroprotective agents. We hypothesized that erythropoietin combined with hypothermia will improve efficacy of neonatal hypoxic-ischemic encephalopathy treatment. In this study, 41 neonates with moderate/severe hypoxic-ischemic encephalopathy were randomly divided into a control group (hypothermia alone for 72 hours, n = 20) and erythropoietin group (hypothermia + erythropoietin 200 IU/kg for 10 days, n = 21). Our results show that compared with the control group, serum tau protein levels were lower and neonatal behavioral neurological assessment scores higher in the eryth-ropoietin group at 8 and 12 days. However, neurodevelopmental outcome was similar between the two groups at 9 months of age. Thesefindings suggest that erythropoietin combined with hypothermia reduces serum tau protein levels and improves neonatal behavioral neu-rology outcome but does not affect long-term neurodevelopmental outcome.     

Expression of Clock genes in the pineal glands of newborn rats with hypoxic-ischemic encephalopathy

Clock genes are involved in circadian rhythm regulation, and surviving newborns with hypoxic-ischemic encephalopathy may present with sleep-wake cycle reversal. This study aimed to determine the expression of the clock genes Clock and Bmal1, in the pineal gland of rats with hypoxic-ischemic brain damage. Results showed that levels of Clock mRNA were not significantly changed within 48 hours after cerebral hypoxia and ischemia. Expression levels of CLOCK and BMAL1 protein were significantly higher after 48 hours. The levels of Bmal1 mRNA reached a peak at 36 hours, but were significantly reduced at 48 hours. Experimental findings indicate that Clock and Bmal1 genes were indeed expressed in the pineal glands of neonatal rats. At the initial stage (within 36 hours) of hypoxic-ischemic brain damage, only slight changes in the expression levels of these two genes were detected, followed by significant changes at 36-48 hours. These changes may be associated with circadian rhythm disorder induced by hypoxic-ischemic brain damage.     

Brain diffusivity in infants with hypoxic-ischemic encephalopathy following whole body hypothermia: preliminary results

Hypoxic-ischemic encephalopathy is an important cause of neuropsychological deficits. Little is known about brain diffusivity in these infants following cooling and its potential in predicting outcome. Diffusion tensor imaging was applied to 3 groups: (1) three infants with hypoxic-ischemic encephalopathy: cooled; (2) three infants with hypoxic-ischemic encephalopathy: noncooled; and (3) four controls. Diffusivity values at the corticospinal tract, thalamus, and putamen were correlated with Apgar scores and early neurodevelopmental outcome. While cooled infants exhibited lower Apgar scores than noncooled infants, their developmental scores at a mean age of 8 months were higher. All groups differed in their diffusivity values with the cooled infants showing better values compared with the noncooled, correlating with early neurodevelopmental outcome. These preliminary results indicate that diffusion tensor imaging performed at an early age in infants with hypoxic-ischemic encephalopathy may forecast clinical outcome and support the neuroprotective effect of hypothermia treatment.     

Predictive value of amplitude-integrated electroencephalography pattern and voltage in asphyxiated term infants

The aim of this study was to correlate amplitude-integrated electroencephalography soon after birth with neurodevelopmental outcome in children who suffered from hypoxic-ischemic encephalopathy. Near term infants with hypoxic-ischemic encephalopathy and amplitude-integrated electroencephalography recording before 6 hours of age were included. Neurologic and cognitive outcome were assessed at 30 months of age and over. Outcome was correlated with either the pattern or voltage of the tracing. Thirty-nine infants were included. Eight died in the immediate neonatal period. At the age of 3 and 6 hours, sensitivity of low voltage to poor outcome was 33% and 42% respectively and of burst suppression pattern to poor outcome was 83% and 75% respectively. Association of voltage to outcome was significant only at 6 hours of age (P = 0.025). Association of pattern to outcome was significant both at 3 and 6 hours of age (P = 0.003, 0.008). These data on amplitude-integrated electroencephalography predictive value early in life were similar to previous studies. Burst suppression pattern, as early as 3 hours of age, is associated with poor outcome. At the age of 6 hours, both low voltage and burst suppression are associated with poor outcome. Pattern seems more sensitive than voltage.     

Electrographic seizures during therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy

Electrographic seizures are common in neonates with hypoxic-ischemic encephalopathy, but detailed data are not available regarding seizure incidence during therapeutic hypothermia. The objective of this prospective study was to determine the incidence and timing of electrographic seizures in term neonates undergoing whole-body therapeutic hypothermia for hypoxic-ischemic encephalopathy as detected by conventional full-array electroencephalography for 72 hours of therapeutic hypothermia and 24 hours of normothermia. Clinical and electroencephalography data were collected from 26 consecutive neonates. Electroencephalograms were reviewed by 2 pediatric neurophysiologists. Electrographic seizures occurred in 17 of 26 (65%) patients. Seizures were entirely nonconvulsive in 8 of 17 (47%), status epilepticus occurred in 4 of 17 (23%), and seizure onset was in the first 48 hours in 13 of 17 (76%) patients. Electrographic seizures were common, were often nonconvulsive, and had onset over a broad range of times in the first days of life.     

Quantitative cranial magnetic resonance imaging in neonatal hypoxic-ischemic encephalopathy

The volume of acute injury detected by diffusion-weighted imaging and quantitative brain growth on serial cranial magnetic resonance imaging was not previously used to predict neurodevelopmental outcomes in infants with neonatal hypoxic-ischemic encephalopathy treated with head cooling. Our longitudinal study involved 16 head-cooled term infants with hypoxic-ischemic encephalopathy who underwent early and follow-up cranial magnetic resonance imaging and follow-up neurologic evaluations, out of 105 infants who received therapeutic hypothermia. The volume of acute injury was measured on initial cranial magnetic resonance imaging, using diffusion-weighted images. Total brain volumes were measured in both early and follow-up magnetic resonance imaging studies. Acute injury volume in the corpus callosum >0.5 cm(3) was associated with developing epilepsy (odds ratio, 20; 95% confidence interval, 1.01-1059.6; P = 0.013). Follow-up whole brain volume was reduced in those with unfavorable outcomes (i.e., epilepsy, cerebral palsy, and delayed developmental milestones), compared with infants without all three outcomes. Although acute brain injury volume and brain growth measurements may be useful predictors of outcomes in neonatal hypoxic-ischemic encephalopathy, the evolution of brain injury in these infants has yet to be fully understood and should be studied prospectively.     

Neuroprotective effects of melatonin administered alone or in combination with topiramate in neonatal hypoxic-ischemic rat model

Purpose: The objective of this study was to compare the effects of two neuroprotective agents; melatonin, a free radical scavenger and topiramate, AMPA/kainate receptor antagonist, administered alone or in combination in neonatal hypoxic-ischemic model. Methods: After being anesthetized, 7-day-old pups underwent ischemia followed by exposure to hypoxia. The pups were divided into 4 groups in order to receive the vehicle, melatonin, topiramate and combination of topiramate and melatonin. These were administered intraperitoneally for three times; the first before ischemia, the second after hypoxia and the third 24 hours after the second dose. After sacrification, infarct volume and apoptosis were evaluated. Results: Percent infarcted brain volume was significantly reduced in rats which received drugs compared with those which received the vehicle. The number of TUNEL positive cells per unit area in hippocampus and cortex were markedly reduced in drug treated groups compared with control group. No significant differences were found regarding percent infarcted brain volume and number of TUNEL positive cells among drug-treated groups. Conclusions: Melatonin and topiramate, administered either alone or in combination significantly reduced the percent infarcted brain volume and number of TUNEL positive cells suggesting that these agents may confer benefit in treatment of infants with hypoxic-ischemic encephalopathy.     

TERM INFANTS WITH HYPOXIC-ISCHEMIC ENCEPHALOPATHY: OUTCOME AT 3.5 YEARS

A total of 167 term neonates with a diagnosis of hypoxic-ischemic encephalopathy (HIE) had detailed neurodevelopmental follow-up at 3.5 years of age. All 66 children with mild HIE were free from handicap; all seven with severe HIE were severely handicapped; and of the 94 with moderate HIE at birth, 21.3 per cent were handicapped. Mean IQ was significantly related to the category of HIE. Within the moderate HIE category, the neurological examination at discharge from the Neonatal Intensive Care Unit was more useful than the presence of neonatal convulsions in identifying children with subsequent developmental delay. Abnormalities on this examination related significantly to an increased number of handicapped children, decreased motor and language skills, and lower IQs. Although neonatal convulsions were associated with an increased number of handicapped children, they did not significantly affect most other developmental outcome measures. In term infants with documented HIE at birth, major neurodevelopmental dysfunction at 3.5 years depended more on prospectively established category of HIE than on other perinatal or social factors.     

Antenatal risk factors associated with unfavorable neurologic status in newborns and at 2 years of age

The aim of this prospective cohort study was to evaluate the influence of different antenatal factors on neurologic signs in the first days of life and neurodevelopmental outcome at 2 years of age. The study group consisted of 390 children drawn from a cohort of 828 consecutive live births. The data about potential antenatal risk factors, birth complications, and neonatal course were abstracted from pregnancy and delivery records and the hospital register. Odds ratio estimates with 95% confidence intervals were used to measure the associations between antenatal factors and neurologic status in newborns and at 2 years of age. Significance level was set at P < .05. At the mean age of 2 years, 49 of 390 children exhibited adverse neurodevelopmental outcome (cerebral palsy and other developmental disorders). The development of 341 children was normal. Comparative analysis of risk factors was conducted. The strongest correlation with development of hypoxic-ischemic encephalopathy during the first days of life was found in trichomoniasis during pregnancy (odds ratio 4.34; 95% confidence interval 1.32-14.23) and acute respiratory disease (temperature > or = 38 degrees C) in the second half of pregnancy (odds ratio 2.86; 95% confidence interval 1.08-7.58). Of various antenatal factors, bacterial vaginosis combined with impending abortion in the first half of pregnancy (odds ratio 4.96; 95% confidence interval 1.35-18.26) had a significant association with adverse outcome at 2 years of age. The presence of at least one complication at delivery placed the child at risk of adverse neurologic outcome (odds ratio 2.44; 95% confidence interval 1.32-4.54). The study provides supportive evidence that antenatal factors associated with maternal infections can influence the development of hypoxic-ischemic encephalopathy and later neurodevelopmental outcome. These children should be assigned to risk groups for early intervention.     

Posthypoxic glucose supplement reduces hypoxic-ischemic brain damage in the neonatal rat

We evaluated the effect of posthypoxic glucose supplement in a neonatal hypoxic-ischemic animal model. Seven-day-old rats underwent bilateral ligation of the carotid arteries, followed by exposure to an 8% oxygen atmosphere for 1 hour. The extent of hypoxic-ischemic brain damage was assessed histologically 72 hours later. Glucose load immediately after the end of the hypoxic exposure reduced the volume of neocortical infarction to 37% of the unsupplemented value, and attenuated ischemic damage in the striatum and the dentate gyrus. At the end of the hypoxic exposure, the brain level of glucose was 0.3 mmol/kg and the level of lactate 9 mmol/kg. Glucose supplement produced a rapid rise in brain glucose level to 3 to 5 mmol/kg over the next 2 hours. Lactate in both brain and plasma gradually fell toward the baseline level during the first hour of recovery. Posthypoxic glucose supplement slightly retarded lactate restitution. At any period of this neonatal model, brain lactate levels did not exceed the toxic level, which is postulated to be responsible for cerebral infarction in adult ischemic models. These results illustrate the important role of glucose in the development of neonatal hypoxic-ischemic encephalopathy and the fact that full cortical infarction can develop even if brain lactate levels are low.     

Flunarizine limits hypoxia-ischemia induced morphologic injury in immature rat brain

We examined the impact of pre-treatment with the calcium antagonist flunarizine on the development of hypoxic-ischemic brain injury in the immature rat. Unilateral carotid artery ligation and subsequent exposure to 2 hours of 8% oxygen in 7-day-old rats was used as a model for perinatal hypoxic-ischemic encephalopathy. This procedure leads to atrophy in the cerebral hemisphere ipsilateral to carotid occlusion, with prominent foci of neuronal infarction in the caudate-putamen (striatum). The morphologic injury develops after 1 1/2 hours of hypoxia; and there is an equivalent time threshold for duration of hypoxic exposure needed to acutely stimulate dopamine release in the ipsilateral striatum. Parenteral administration of 30 mg/kg of flunarizine before hypoxic exposure limited both the release of dopamine acutely and the extent of morphologic damage observed two weeks after the insult. Oral administration of 30 mg/kg of flunarizine in a different vehicle prevented morphologic damage but had no effect on stimulated dopamine release. The drug vehicle for the parenteral preparation also prevented tissue injury, but to a lesser degree than flunarizine. However the parenteral vehicle was equipotent with parenteral flunarizine in limiting acute stimulation of dopamine release. The results demonstrate that flunarizine has potent neuroprotective properties against morphologic brain injury from hypoxia-ischemia, acting by a mechanism which is independent of effects on dopamine release.     

Prognostic value of 1H-MRS in neonatal encephalopathy

The aim of this study was to determine the prognostic value of proton magnetic resonance spectroscopy in neonatal encephalopathy. Studies were carried out in 11 consecutive term newborns with encephalopathy probably caused by hypoxic-ischemic injury. The clinical evaluation included pregnancy data, labor conditions, encephalopathy grade, presence of seizures, and necessity of antiepileptic drug therapy. Polygraphic recordings were obtained in all cases. Interest areas evaluated by spectroscopy were the basal ganglia and thalami. Among the cases, N-acetylaspartate/creatine, choline/creatine, and lactate/creatine ratios were calculated and related to the clinical variables, polygraphic recordings, and 6-month neurodevelopmental outcome. Abnormal follow-up occurred in 5 of 11 patients (45.4%) and was clearly related to an Apgar score <5 at 5 minutes (P = 0.003), encephalopathy grade (P = 0.02), early neonatal seizures (P = 0.02), and antiepileptic therapy (P = 0.01). No relationship was observed between spectroscopy results and polygraphic recordings profile. The lowest mean N-acetylaspartate/creatine ratio was observed in four of five patients with an adverse outcome and, although not statistically significant, demonstrated a clear trend to unfavorable follow-up (t test = 0.06). The choline/creatine ratios could not be related to follow-up in our sample. The most consistently observed abnormality on the spectra was the presence of the lactate peak in four of five patients with unfavorable outcome, with a high relative risk to determine evolution in the sample, relative risk 7.0 (chi2 = 0.01, 95% confidence interval = 1.1-42.9).     

Hypoxic-ischemic encephalopathy: correlation of serial MRI and outcome

Twenty-four patients with hypoxic-ischemic encephalopathy were examined with serial magnetic resonance imaging up to 4 years of age. Magnetic resonance imaging studies were performed in the neonatal period, at the fourth month and the fourth year of age, and the findings were compared with the patients' neurodevelopmental outcome at the fourth year of age. Periventricular signal alterations and deep gray matter involvement were usually evident in the initial magnetic resonance imaging studies, and encephalomalacia, periventricular leukomalacia, and atrophy were the common findings on follow-up magnetic resonance imaging studies. In the patients with hypoxic-ischemic encephalopathy, some correlation between magnetic resonance imaging findings and neurodevelopmental outcome was recognized. The patients with deep gray matter involvement on the initial magnetic resonance imaging had a poor prognosis, and the ones with normal magnetic resonance imaging findings had a favorable neurodevelopmental outcome. On the follow-up magnetic resonance imaging findings, encephalomalacia and periventricular leukomalacia were associated with poor neurodevelopmental outcome. In predicting the neurologic outcome at 4 years of age, magnetic resonance imaging findings of the neonatal period had the highest negative predictive value, whereas magnetic resonance imaging findings at 4 months of age and 4 years of age had the highest positive predictive value.     

Upregulation of calpain activity in neonatal rat brain after hypoxic-ischemia

Neonatal rats were subjected to transient cerebral hypoxic-ischemia (unilateral occlusion of the common carotid cartery plus 7.7% O₂ for 2 h) and allowed to recover for 0 min, 30 min or 20 h. The calpain and calpastatin activities were assayed in subcellular fractions of the ipsilateral, hypoxic-ischemic and the contralateral, hypoxic hemisphere. An upregulation of calpain activity occurred in the hypoxic hemisphere, both in the major, cytosolic fraction and in the hypotonic, membrane associated fraction (110% and 133% of controls, respectively). The hypoxic-ischemic hemisphere displayed a decrease in calpain activity in the cytosolic fraction but an increase in the hypotonic fraction (90% and 111% of controls, respectively). The changes in calpastatin activity were less pronounced. This indicates that an upregulation of calpain activity occurs in parallel with development of hypoxic-ischemic damage. However, this upregulation is not necessarily coupled to development of injury as lesions are not seen in the hypoxic hemisphere.     

Factors predictive of seizures and neurologic outcome in perinatal depression

To identify which early clinical variables are predictive of outcome in newborns with perinatal depression, we prospectively examined newborns with persistently abnormal neurologic examinations at 48 hours and (1) arterial pH 相似文献   

Neuron-specific enolase levels and neuroimaging in asphyxiated term newborns

The study was designed to investigate the cerebrospinal fluid and serum levels of neuron-specific enolase, along with cranial ultrasonography, magnetic resonance imaging (MRI), and electroencephalography (EEG), for predicting the clinical state and neurologic outcome of 26 asphyxiated term newborns. The babies were graded according to the Sarnat and Sarnat classification. Cerebrospinal fluid neuron-specific enolase levels of the 18 babies in the whole hypoxic-ischemic encephalopathy group were higher than the 8 babies in the "no encephalopathy" group. Cerebrospinal fluid neuron-specific enolase levels of 13 cases in the hypoxic-ischemic encephalopathy grade 2 and 3 groups (high-risk group) were higher than both the no encephalopathy and hypoxic-ischemic encephalopathy grade 1 groups when pooled. Cerebrospinal fluid neuron-specific enolase levels of the 7 newborns in the hypoxic-ischemic encephalopathy grade 3 group were also significantly higher than the 5 in the hypoxic-ischemic encephalopathy grade 1 group. The findings of cranial MRI, EEG, and cerebrospinal fluid neuron-specific enolase levels were correlated with each other and the clinical grade of the patients and also were predictive of the neurologic outcome at 1 year of age. Cerebrospinal fluid neuron-specific enolase levels, cranial MRI, and EEG are predictive of outcome of hypoxic-ischemic brain damage in asphyxiated newborns, and this predictivity would increase with the combination of these diagnostic parameters.     

Neuroimaging of neonatal encephalopathies

Neonatal brain disorders consist of a wide chapter including brain malformations, hypoxic-ischemic encephalopathy (HIE), intracranial infections, perinatal trauma and metabolic encephalopathy. We will focus here on HIE, intracranial infections (especially materno-fetal infection with or without prolonged and/or premature rupture of membranes) and metabolic encephalopathy, those three conditions being the most frequent so far in our experience. Neonatal stroke is also analyzed. Moreover minor perinatal events might be superimposed on an already damaged (infective, edematous, metabolically abnormal or maldeveloped) brain, highlighting the main role and potential benefits of neuroimaging during the neonatal period. The different methods of brain imaging are thus reported with their advantages and disadvantages.     

Single-nucleotide polymorphism screening and RNA sequencing of key messenger RNAs associated with neonatal hypoxic-ischemia brain damage

A single-nucleotide polymorphism(SNP)is an alteration in one nucleotide in a certain position within a genome.SNPs are associated with disease susceptibility.However,the influences of SNPs on the pathogenesis of neonatal hypoxic-ischemic brain damage remain elusive.Seven-day-old rats were used to establish a hypoxic ischemic encephalopathy model.SNPs and expression profiles of mRNAs were analyzed in hypoxic ischemic encephalopathy model rats using RNA sequencing.Genes exhibiting SNPs associated with hypoxic ischemic encephalopathy were identified and studied by gene ontology and pathway analysis to identify their possible involvement in the disease mechanism.We identified 89 up-regulated genes containing SNPs that were mainly located on chromosome 1 and 2.Gene ontology analysis indicated that the up-regulated genes containing SNPs are mainly involved in angiogenesis,wound healing and glutamatergic synapse and biological processing of calcium-activated chloride channels.Signaling pathway analysis indicated that the differentially expressed genes play a role in glutamatergic synapses,long-term depression and oxytocin signaling.Moreover,intersection analysis of high throughput screening following PubMed retrieval and RNA sequencing for SNPs showed that CSRNP1,DUSP5 and LRRC25 were most relevant to hypoxic ischemic encephalopathy.Significant up-regulation of genes was confirmed by quantitative real-time polymerase chain reaction analysis of oxygen-glucose-deprived human fetal cortical neurons.Our results indicate that CSRNP1,DUSP5 and LRRC25,containing SNPs,may be involved in the pathogenesis of hypoxic ischemic encephalopathy.These findings indicate a novel direction for further hypoxic ischemic encephalopathy research.This animal study was approved on February 5,2017 by the Animal Care and Use Committee of Kunming Medical University,Yunnan Province,China(approval No.kmmu2019038).Cerebral tissue collection from a human fetus was approved on September 30,2015 by the Ethics Committee of Kunming Medical University,China(approval No.2015-9).     

Apparent diffusion coefficient pseudonormalization time in neonatal hypoxic-ischemic encephalopathy

The apparent diffusion coefficient changes with time after hypoxic-ischemic brain injury. In this study, we quantitatively examined the relationship between the apparent diffusion coefficient and postnatal age for neonates with hypoxic-ischemic encephalopathy and poor outcome, and determined the postnatal age at which these values cannot be distinguished from those of neonates without hypoxic-ischemic encephalopathy (pseudonormalization time). Diffusion-weighted brain images were obtained from clinical scans of term neonates with hypoxic-ischemic encephalopathy and poor outcome (12 neonates, 23 scans) and from control subjects (30 neonates, 31 scans). The correlation between apparent diffusion coefficient and postnatal age was investigated for several brain regions. Pseudonormalization times were determined (1) from the intersection of the regression lines for the hypoxic-ischemic encephalopathy and control groups, as well as (2) from intrasubject apparent diffusion coefficient changes between two scans within a small subgroup. Pseudonormalization times from the regression ranged from 8.3 +/- 1.9 days to 10.1 +/- 2.1 days. Slightly (approximately 1 day) longer values were obtained from the intrasubject analysis. The results suggest that, although abnormally decreased apparent diffusion coefficient values may be evident from approximately 2 days to almost 1 week of postnatal age, abnormally elevated values may not be apparent until late in the second week of life.