Associated factors in neonatal hypoglycemic brain injury

Neonatal hypoglycaemia

Low blood concentrations of glucose (hypoglycaemia) soon after birth are common because of the delayed metabolic transition from maternal to endogenous neonatal sources of glucose. Because glucose is the main energy source for the brain, severe hypoglycaemia can cause neuroglycopenia (inadequate supply of glucose to the brain) and, if severe, permanent brain injury. Routine screening of infants at risk and treatment when hypoglycaemia is detected are therefore widely recommended. Robust evidence to support most aspects of management is lacking, however, including the appropriate threshold for diagnosis and optimal monitoring. Treatment is usually initially more feeding, with buccal dextrose gel, followed by intravenous dextrose. In infants at risk, developmental outcomes after mild hypoglycaemia seem to be worse than in those who do not develop hypoglycaemia, but the reasons for these observations are uncertain. Here, the current understanding of the pathophysiology of neonatal hypoglycaemia and recent evidence regarding its diagnosis, management, and outcomes are reviewed. Recommendations are made for further research priorities.

Relationship between EEG spectral power and dysglycemia with neurodevelopmental outcomes after neonatal encephalopathy

OBJECTIVE

We investigated how electroencephalography (EEG) quantitative measures and dysglycemia relate to neurodevelopmental outcomes following neonatal encephalopathy (NE).

METHODS

This retrospective study included 90 neonates with encephalopathy who received therapeutic hypothermia. EEG absolute spectral power was calculated during post-rewarming and 2-month follow-up. Measures of dysglycemia (hypoglycemia, hyperglycemia, and glycemic lability) and glucose variability were computed for the first 48 h of life. We evaluated the ability of EEG and glucose measures to predict neurodevelopmental outcomes at ≥ 18 months, using logistic regressions (with area under the receiver operating characteristic [AUROC] curves).

RESULTS

The post-rewarming global delta power (average all electrodes), hyperglycemia and glycemic lability predicted moderate/severe neurodevelopmental outcome separately (AUROC = 0.8, 95%CI [0.7,0.9], p < .001) and even more so when combined (AUROC = 0.9, 95%CI [0.8,0.9], p < .001). After adjusting for NE severity and magnetic resonance imaging (MRI) brain injury, only global delta power remained significantly associated with moderate/severe neurodevelopmental outcome (odds ratio [OR] = 0.9, 95%CI [0.8,1.0], p = .04), gross motor delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), global developmental delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), and auditory deficits (OR = 0.9, 95%CI [0.8,1.0], p = .03).

CONCLUSIONS

In NE, global delta power post-rewarming was predictive of outcomes at ≥ 18 months.

SIGNIFICANCE

EEG markers post-rewarming can aid prediction of neurodevelopmental outcomes following NE.

Factors associated with neonatal hyperinsulinemic hypoglycemia, a case-control study

OBJECTIVES

We aimed to identify perinatal risk factors associated with hyperinsulinemic hypoglycemia in neonates. Secondary objectives included an examination of clinical and biochemical characteristics at the time of diagnosis and an exploration of the duration of diazoxide therapy.

METHODS

A case-control study was conducted, involving individual chart reviews of inborn infants diagnosed with hyperinsulinemic hypoglycemia (the HH group) between 2014 and 2021. These cases were paired with controls (the non-HH group) belonging to the same gestational age (GA) strata who did not exhibit HH or only had transient postnatal hypoglycemia.

RESULTS

A total of 52 infants with HH were matched with corresponding controls. The mean GA in the HH group was 34.4 ± 3.1 weeks. Notably, the HH group exhibited lower mean minimum plasma glucose (PG) levels and required higher glucose infusion rates in comparison to the non-HH group (26.5 ± 15.6 vs. 49.1 ± 37.7 mg/dL and 12.9 ± 3.8 vs. 5.7 ± 2.1 mg/kg/min, respectively; p<0.001 for both). After adjusting for potential confounding factors, only two variables, fetal growth restriction (FGR) and neonatal sepsis, demonstrated significant associations with HH (adjusted odds ratio [95 % confidence interval]: 8.1 [2.1-31.0], p=0.002 and 6.3 [1.9-21.4], p=0.003, respectively). The median duration of diazoxide therapy for the HH group was 4 months.

CONCLUSIONS

FGR and neonatal sepsis emerged as notable risk factors for HH. These infants exhibited lower PG levels and necessitated higher glucose infusion rates compared to their non-HH counterparts. Importantly, a substantial proportion of the HH group received diazoxide therapy, with a median treatment duration of 4 months.

The relationship between neonatal hypoglycaemia and cord blood C-peptide levels in neonates of birthing individuals with type 1 diabetes

INTRODUCTION

Neonates of individuals with type 1 diabetes (T1D) are at increased risk of neonatal hypoglycaemia. It is hypothesised that this is a result of birthing-individual hyperglycaemia and subsequent foetal hyperinsulinemia.

AIMS

To test for association between clinically significant neonatal hypoglycaemia (requiring intravenous glucose treatment) and cord-blood c-peptide (CBCP) concentrations in birthing-individuals with T1D.

MATERIALS AND METHODS

This is a prospective cohort study of individuals with T1D followed at a single tertiary centre. Clinical variables and glucose control during pregnancy were recorded. Cord-blood was collected and CBCP concentrations determined. The correlation between clinically significant neonatal hypoglycaemia and CBCP concentrations was determined.

RESULTS

Fifty-four pregnant individuals and their newborns were included in the study. Individuals to neonates who experienced hypoglycaemia had longer diabetes duration (19 vs. 13 years, respectively, p = 0.023), higher HbA1c at conception (7.3 [6.3-8.8] vs. 6.5 [6.0-7.0], respectively, p = 0.042) and higher rates of caesarian section (73.3% vs. 28.2%, respectively, p = 0.005) than individuals to those who did not. CBCP levels were significantly higher in neonates with clinically significant neonatal hypoglycaemia as compared to those who did not experience hypoglycaemia (3.3 mcg/L vs. 1.9 mcg/L, respectively, p = 0.002). After adjustment for possible confounders, every 1 unit higher in CBCP level was associated with a 1.46 (1.02-2.09, p = 0.035)-fold greater risk for neonatal hypoglycaemia. No significant differences were observed in either birthing individual complications or glucose control indices during pregnancy between the two groups.

CONCLUSIONS

In neonates of individuals with T1D, higher CBCP levels are an independent risk factor for clinically significant neonatal hypoglycaemia.

Risk Factors for Hypoglycemia Among Neonates: A Prospective Cohort Study Among Pregnant People With Gestational Diabetes Mellitus

OBJECTIVE

Neonatal hypoglycemia (NH) is the most frequent complication in neonates born to pregnant people with gestational diabetes mellitus (GDM) and an important cause of brain damage and death of neonates. We explored the risk factors for NH in neonates of pregnant people with GDM.

METHODS

A prospective cohort study was conducted involving 322 pregnant people with GDM at the Guangzhou Women and Children's Medical Centre. Maternal sociodemographic, clinical, and biochemical data, as well as general characteristics of neonates, were collected to analyze their associations with NH in neonates of pregnant people with GDM.

RESULTS

The incidence of NH among neonates of pregnant people with GDM was 19.57% (63/322). After adjustment for confounders, the factors significantly associated with an increased risk of NH were cesarean delivery (relative risk [RR] = 3.44; 95% confidence interval [CI], 1.83-6.45), red blood cell (RBC) count (RR = 2.19; 95% CI, 1.22-3.96), and 1-hour postprandial glucose (RR = 2.35; 95% CI, 1.23-4.46) during pregnancy, whereas later gestational age (RR = 0.58; 95% CI, 0.42-0.80) and multiparity (RR = 0.32; 95% CI, 0.16-0.66) were associated with a reduced risk of NH.

CONCLUSION

Cesarean delivery, maternal 1-hour glucose of the oral glucose tolerance test, and increased RBC count of pregnant people with GDM are independent risk factors for NH, while later gestational age and multiparity are protective factors.

Neurologic Disorders of the Foal

Neurologic disease of foals is a diagnostic and therapeutic challenge for veterinarians. Disease conditions such as neonatal encephalopathy are seen as well as developmental and congenital defects, bacterial infections, and trauma. Neonatal encephalopathy can be considered a "syndrome" with a variety of causes resulting in a similar clinical presentation. These causes can be categorized as maladaptation, hypoxic/ischemic encephalopathy, and metabolic abnormalities, all leading to signs of cerebral and brainstem disease. Spinal cord signs may occasionally be seen, but these signs are usually overshadowed by cerebral disease. Treatment in most cases involves supportive care and outcome is favorable in most cases.

Impact of glucose metabolism on the developing brain

Glucose is the most important substrate for proper brain functioning and development, with an increased glucose consumption in relation to the need of creating new brain structures and connections. Therefore, alterations in glucose homeostasis will inevitably be associated with changes in the development of the Nervous System. Several studies demonstrated how the alteration of glucose homeostasis - both hyper and hypoglycemia- may interfere with the development of brain structures and cognitivity, including deficits in intelligence quotient, anomalies in learning and memory, as well as differences in the executive functions. Importantly, differences in brain structure and functionality were found after a single episode of diabetic ketoacidosis suggesting the importance of glycemic control and stressing the need of screening programs for type 1 diabetes to protect children from this dramatic condition. The exciting progresses of the neuroimaging techniques such as diffusion tensor imaging, has helped to improve the understanding of the effects, outcomes and mechanisms underlying brain changes following dysglycemia, and will lead to more insights on the physio-pathological mechanisms and related neurological consequences about hyper and hypoglycemia.

Comparison of risk-of-bias assessment approaches for selection of studies reporting prevalence for economic analyses

OBJECTIVES

Within cost-effectiveness models, prevalence figures can inform transition probabilities. The methodological quality of studies can inform the choice of prevalence figures but no single obvious candidate tool exists for assessing quality of the observational epidemiological studies for selecting prevalence estimates. We aimed to compare different tools to assess the risk of bias of studies reporting prevalence, and develop and compare possible numerical scoring systems using these tools to set a threshold for inclusion of reports of prevalence in an economic analysis of neonatal hypoglycaemia.

DESIGN

Assessments of bias using two tools (Joanna Briggs Institute (JBI) Checklist for Prevalence Studies and a modified version of Risk Of Bias In Non-randomised Studies-of Interventions (ROBINS-I)) were compared for 18 studies relevant to a single setting (neonatal hypoglycaemia). Inclusions of studies for use in a decision analysis model were considered based on summary scores derived from these tools.

RESULTS

Both tools were considered easy to use and produced dispersed scores for each of the 40 study-outcome combinations. The modified ROBINS-I scores were more skewed than the JBI scores, particularly at higher thresholds. The studies selected for inclusion are generally the same using either tool; if 50% was used as the cut-off threshold using the Applicable Score both tools would yield the same results. However, the JBI tool is shorter and may be easier to interpret and apply to studies that do not involve a control group, while the modified ROBINS-I tool assesses more methodological detail in studies that include a control group.

CONCLUSION

Both tools performed well for systematically assessing studies that report on outcome prevalence and provided similar discrimination between studies for risk of bias. This convergent validity supports use of both tools for the purpose of assessing risk of bias and selecting studies that report prevalence for inclusion in economic analyses.

The association between novel glucose indices in parturients with type 1 diabetes mellitus and clinically significant neonatal hypoglycemia

The aim of this study was to determine the association between glucose control indices of parturient with type 1 diabetes (T1DM), treated with an insulin pump and utilizing continuous glucose monitoring (CGM), and clinically significant neonatal hypoglycemia. This was a retrospective cohort study which included 37 pregnant women with T1DM. All women were followed at a single tertiary center and had available CGM data. The association between maternal glucose indices before delivery and the risk for neonatal hypoglycemia requiring IV glucose (clinically significant hypoglycemia) was assessed using logistic regression. Mothers to neonates that experienced clinically significant hypoglycemia had a higher glucose standard deviation (SD) before delivery than did mothers to neonates who did not (25.5 ± 13 mg/dL vs. 14.7 ± 6.7 mg/dl respectively; p = .008). This association persisted after adjustment for maternal age, maternal pregestational body mass index (BMI), gestational age at delivery, neonatal birth weight, large for gestational age (LGA) and gender. This study demonstrates an association between high maternal glucose standard deviation before delivery and the risk for clinically significant neonatal hypoglycemia. Larger studies are needed to confirm these results and further explore the role of intrapartum glucose variability in the prediction and prevention of significant neonatal hypoglycemia.

Synergic interaction between ritodrine and magnesium sulfate on the occurrence of critical neonatal hyperkalemia: A Japanese nationwide retrospective cohort study

Our aim was to evaluate the association between ritodrine and magnesium sulfate (MgSO4) and the occurrence of neonatal hyperkalemia or hypoglycemia among late preterm infants in a retrospective cohort study. We used a nationwide obstetrical database from 2014. A total of 4,622 live preterm infants born at 32-36 gestational weeks participated. Fourteen risk factors based on both clinical relevance and univariate analysis were adjusted in multivariable logistic regression analyses. Neonatal hyperkalemia and hypoglycemia occurred in 7.6% (284/3,732) and 32.4% (1,458/4,501), respectively. Occurrence of hyperkalemia was associated with concomitant usage of ritodrine and MgSO4 compared with no usage (adjusted odds ratio [aOR] 1.53, 95% confidence interval [CI] 1.09-2.15). Occurrence of hypoglycemia was associated with ritodrine alone (aOR 2.58 [CI 2.21-3.01]) and with concomitant usage of ritodrine and MgSO4 (aOR 2.59 [CI 2.13-3.15]), compared with no usage, and was associated with long-term usage (≥ 48 hours) of ritodrine and cessation directly before delivery. In conclusion, in late preterm infants, usage of ritodrine together with MgSO4 was associated with occurrence of critical neonatal hyperkalemia, and long-term usage of ritodrine and cessation directly before delivery were associated with neonatal hypoglycemia.

Identifying risk effectors involved in neonatal hypoglycemia occurrence

Hypoglycemia is a common metabolic condition in neonatal period, but severe and persistent hypoglycemia can cause neurological damage and brain injury. The aim of the present study was to analyze the risk factors of neonatal hypoglycemia in clinic. A total of 135 neonatal hypoglycemia infants and 135 healthy infants were included in the present study. The differences in birth weight between neonatal hypoglycemia group and healthy control group were analyzed via t test. The associations between neonatal blood sugar level and relevant characteristic factors were explored using χ² test. Binary logistic regression analysis was used to analyze risk factors related to the incidence of neonatal hypoglycemia. The results showed that the average birth weight was matched in neonatal hypoglycemia group and healthy control group. Neonatal blood sugar level of the infants was significantly associated with born term, birth weight, feed, gestational diabetes mellitus (GDM) and hypothermia (all P<0.05). Besides, logistic regression analysis showed that babies’ born term (odds ratio (OR) = 2.715, 95% confidence interval (95% CI): 1.311–5.625), birth weight (OR = 1.910, 95% CI: 1.234–2.955), improper feeding (OR = 3.165, 95% CI: 1.295–7.736) and mother’s GDM (OR = 2.184, 95% CI: 1.153–4.134) were high risk factors for neonatal hypoglycemia. The incidence of hypoglycemia in infants was significantly associated with various clinical factors. And monitoring these risk factors is one of important measures to reduce long-term neurological damage caused by neonatal hypoglycemia.

Timing of elective pre-labour caesarean section: A decision analysis

BACKGROUND

Since caesarean sections (CSs) before 39+0  weeks gestation are associated with higher rates of neonatal respiratory morbidity, it is recommended to delay elective CSs until 39+0  weeks. However, this bears the risk of earlier spontaneous labour resulting in unplanned CSs, which has workforce and resource implications, specifically in smaller obstetric units.

AIM

To assess, in a policy of elective CSs from 39+0  weeks onward, the number of unplanned CSs to prevent one neonate with respiratory complications, as compared to early elective CS.

MATERIALS AND METHODS

We performed a decision analysis comparing early term elective CS at 37+0-6 or 38+0-6  weeks to elective prelabour CS, without strict medical indication, at 39+0-6  weeks, with earlier unplanned CS, in women with uncomplicated singleton pregnancies. We used literature data to calculate the number of unplanned CSs necessary to prevent one neonate with respiratory morbidity.

RESULTS

Planning all elective CSs at 39+0-6  weeks required 10.9 unplanned CSs to prevent one neonate with respiratory morbidity, compared to planning all elective CSs at 38+0-6  weeks. Compared to planning all elective CSs at 37+0-6  weeks we needed to perform 3.3 unplanned CSs to prevent one neonate with respiratory morbidity.

CONCLUSION

In a policy of planning all elective pre-labour CSs from 39+0  weeks of gestation onward, between three and 11 unplanned CSs have to be performed to prevent one neonate with respiratory morbidity. Therefore, in our opinion, fear of early term labour and workforce disutility is no argument for scheduling elective CSs <39+0  weeks.

Neonatal Hypoglycemia: Is There a Sweet Spot?

Hypoglycemia is one of the most common neonatal problems. Despite increasing evidence that hypoglycemia is linked to neurologic impairment, knowledge regarding the specific value or duration of hypoglycemia that results in injury to the brain remains unclear. Current published statements/guidelines focused on preventing clinically significant hypoglycemia are conflicting and continue to be based on low evidence. This article reviews transitional events leading to extrauterine euglycemia, risk factors contributing to transient or persistent hypoglycemia, and common treatment approaches. Current information related to neurodevelopmental outcomes and screening strategies to prevent significant hypoglycemia with early treatment is described.

Presumed Neuroglycopenia Caused by Severe Hypoglycemia in Horses

BACKGROUND

Neuroglycopenia refers to a shortage of glucose in the brain resulting in neuronal dysfunction and death if left untreated. Presumed neuroglycopenia has not been described in horses.

OBJECTIVE

To report neurological signs in horses with presumed neuroglycopenia as the result of severe hypoglycemia.

ANIMALS

Ninety horses (hours to 28 years of age) diagnosed with hypoglycemia (blood glucose concentration < 75 mg/dL [< 4.2 mmol/L]).

METHODS

Retrospective study. Electronic medical records were searched. Signalment, history, complaint, clinical signs, laboratory findings including CSF analysis, electroencephalogram, clinical or definitive diagnosis, and outcome were recorded. Kruskal-Wallis analysis of variance and logistic regression were used to investigate association between blood glucose concentration and data extracted. Statistical significance was set at P < 0.05.

RESULTS

Thirty-eight and 52 horses had mild (50-74 mg/dL [2.8-4.1 mmol/L]), and severe hypoglycemia (< 50 mg/dL [< 2.8 mmol/L]), respectively. Most common causes of hypoglycemia included liver and gastrointestinal (40%) disease, sepsis (33%), neoplasia (7%), and insulin-induced (4%). Most common neurologic deficits included obtundation (100%), seizures (42%), and disorientation (22%). CSF-glucose was severely low (mean 2.5 mg/dL [0.1 mmol/L], median 0 mg/dL). Paroxysmal discharges in support of seizures were identified in the occipital (visual) and parietal (closest to temporal-auditory) cortical regions upon EEG examination (8/8 horses).

CONCLUSIONS AND CLINICAL IMPORTANCE

Neuroglycopenia is presumed to occur in horses as the result of severe hypoglycemia. Subclinical seizures, and intermittent blindness and deafness of cortical origin can occur. Severe altered state of consciousness and seizures can be observed at a blood glucose cut-off value of < 42 mg/dL (< 2.3 mmol/L).

Cost Analysis of Cot-Side Screening Methods for Neonatal Hypoglycaemia

BACKGROUND

Babies at risk of neonatal hypoglycaemia are often screened using cot-side glucometers, but non-enzymatic glucometers are inaccurate, potentially resulting in over-treatment and under-treatment, and low values require laboratory confirmation. More accurate enzymatic glucometers are available but at apparently higher costs.

OBJECTIVE

Our objective was to compare the cost of screening for neonatal hypoglycaemia using point-of-care enzymatic and non-enzymatic glucometers.

METHODS

We used a decision tree to model costs, including consumables and staff time. Sensitivity analyses assessed the impact of staff time, staff costs, probability that low results are confirmed via laboratory testing, false-positive and false-negative rates of non-enzymatic glucometers, and the blood glucose concentration threshold.

RESULTS

In the primary analysis, screening using an enzymatic glucometer cost NZD 86.94 (USD 63.47) while using a non-enzymatic glucometer cost NZD 97.08 (USD 70.87) per baby. Sensitivity analyses showed that using an enzymatic glucometer is cost saving with wide variations in staff time and costs, irrespective of the false-positive level of non-enzymatic glucometers, and where ≥78% of low values are laboratory confirmed. Where non-enzymatic glucometers may be less costly (e.g., false-negative rate exceeds 15%), instances of hypoglycaemia will be missed. Reducing the blood glucose concentration threshold to 1.94 mmol/L reduced the incidence of hypoglycaemia from 52 to 13%, and the cost of screening using a non-enzymatic glucometer to NZD 47.71 (USD 34.83).

CONCLUSIONS

In view of their lower cost in most circumstances and greater accuracy, enzymatic glucometers should be routinely utilised for point-of-care screening for neonatal hypoglycaemia.

Hypoglycemia in the preterm neonate: etiopathogenesis, diagnosis, management and long-term outcomes

Glucose, like oxygen, is of fundamental importance for any living being and it is the major energy source for the fetus and the neonate during gestation. The placenta ensures a steady supply of glucose to the fetus, while birth marks a sudden change in substrate delivery and a major change in metabolism. Hypoglycemia is one of the most common pathologies encountered in the neonatal intensive care unit and affects a wide range of neonates. Preterm, small for gestational age (GA) and intra-uterine growth restricted neonates are especially vulnerable due to their lack of metabolic reserves and associated co-morbidities. Nearly 30-60% of these high-risk infants are hypoglycemic and require immediate intervention. Preterm neonates are uniquely predisposed to developing hypoglycemia and its associated complications due to their limited glycogen and fat stores, inability to generate new glucose using gluconeogenesis pathways, have higher metabolic demands due to a relatively larger brain size, and are unable to mount a counter-regulatory response to hypoglycemia. In this review we will discuss the epidemiology; pathophysiology; clinical presentation; management and neurodevelopmental outcomes in affected infants and summarize evidence to develop a rational and scientific approach to this common problem.

Neurodevelopmental Outcome of Asymptomatic Hypoglycemia Compared With Symptomatic Hypoglycemia and Euglycemia in High-Risk Neonates

AIMS

We assessed the neurodevelopmental outcome at one year of age of children with asymptomatic neonatal hypoglycemia and compared their outcome with that of symptomatic hypoglycemic and euglycemic neonates.

METHOD

Seventy two hypoglycemic (plasma glucose less than 50 mg/dL) neonates, both symptomatic (n = 27) and asymptomatic (n = 45), and 70 weight- and gestation-matched euglycemic neonates of gestational age greater than 32 weeks were enrolled during the first week of life then assessed for neurodevelopmental outcome at corrected age six and 12 months (n = 67 and 62 in hypoglycemia group and 63 and 54 in euglycemia group, with the rest lost to follow-up, and death = 1).

RESULTS

At one year, 8% (five of 62, four in symptomatic and one in asymptomatic group) of hypoglycemic neonates developed cerebral palsy. Mean motor and mental development quotients were significantly lower at corrected ages six and 12 months in any hypoglycemia (P < 0.001) and if blood glucose was less than 40 mg/dL (P < 0.001) when compared with euglycemia. Symptomatic infants had lower motor development quotient (P = 0.004 and 0.003) and mental development quotient (P = 0.001 and 0.001) at corrected ages six and 12 months than asymptomatic infants, and asymptomatic infants had lower motor development quotient (P ≤ 0.001 and 0.004) and mental development quotient (P = 0.001 and 0.004) than the euglycemic group at corrected ages six and 12 months, respectively. Blood glucose of less than 40 mg/dL had high sensitivity (83% for motor development quotient and 81% for mental development quotient) for development quotient scores of less than 85.

CONCLUSION

Hypoglycemia, both symptomatic and asymptomatic, leads to adverse neurodevelopmental outcome when compared with euglycemia, although it was worse in the symptomatic group and at blood glucose less than 40 mg/dL.

Understanding the Implications of Birth Weight

Neonatal growth parameters include birth weight, length, and head circumference. Weight, as it relates to gestational age, is monitored closely during pregnancy to assess the appropriate growth of the fetus. At birth, it becomes an important parameter to assess the health and well-being of the newborn. Birth weight carries implications for nursing care and monitoring of the newborn's transition to extrauterine life. The importance of birth weight assessment and its interpretation will be reviewed, along with the implications for immediate neonatal care and potential long-term effects on an infant's health outcomes.

Clinical and Molecular Variability in Patients with PHKA2 Variants and Liver Phosphorylase b Kinase Deficiency

Glycogen storage disease (GSD) type IX is a rare disease of variable clinical severity affecting primarily the liver tissue. Individuals with liver phosphorylase b kinase (PhK) deficiency (GSD IX) can present with hepatomegaly with elevated serum transaminases, ketotic hypoglycemia, hyperlipidemia, and poor growth with considerable variation in clinical severity. PhK is a cAMP-dependent protein kinase that phosphorylates the inactive form of glycogen phosphorylase, phosphorylase b, to produce the active form, phosphorylase a. PhK is a heterotetramer; the alpha 2 subunit in the liver is encoded by the X-linked PHKA2 gene. About 75% of individuals with liver PhK deficiency have mutations in the PHKA2 gene; this condition is also known as X-linked glycogenosis (XLG). Here we report the variability in clinical severity and laboratory findings in 12 male patients from 10 different families with X-linked liver PhK deficiency caused by mutations in PHKA2. We found that there is variability in the severity of clinical features, including hypoglycemia and growth. We also report additional PHKA2 variants that were identified in 24 patients suspected to have liver PhK deficiency. The basis of the clinical variation in GSDIX due to X-linked PHKA2 gene mutations is currently not well understood. Creating systematic registries, and collecting longitudinal data may help in better understanding of this rare, but common, glycogen storage disorder.

SYNOPSIS

Liver phosphorylase b kinase (PhK) deficiency caused due to mutations in X-linked PHKA2 is highly variable.

Hypoglycaemia in hospitalised neonatal calves: Prevalence, associated conditions and impact on prognosis

Hypoglycaemia has traditionally been associated with neonatal diarrhoea and endotoxaemia in calves, but the clinical relevance of this finding in spontaneously diseased calves has not previously been evaluated. To determine the prevalence and prognostic relevance of severe hypoglycaemia (plasma glucose concentration < 2 mmol/L), data from 10,060 hospitalised calves (≤21 days of age) were retrospectively analysed. Additionally, clinical findings and diagnoses in a subset of 100 calves with severe hypoglycaemia were compared with those in 100 randomly selected calves with initial plasma glucose concentrations in the reference range (4.4-6.9 mmol/L). The prevalence of severe hypoglycaemia in the whole study sample was 6.3%. Severe hypoglycaemia was associated with a poor survival rate of 20.6% vs. 74.0% discharged animals in the group of calves with initial normoglycaemia. Review of medical records revealed that severe hypoglycaemia was significantly associated with clinical or necropsy evidence of septicaemia, hypothermia, history or clinical evidence of malnutrition, and peritonitis of varied origin, but not with the presence of neonatal diarrhoea. Only 10 of 100 calves with severe hypoglycaemia showed central nervous involvement such as seizures and opisthotonus. In conclusion, severe hypoglycaemia has a low prevalence in diseased calves in a hospital setting, but is associated with serious health problems and therefore a high risk of non-survival. Severe hypoglycaemia was not easily diagnosed based on clinical signs, but should be suspected in calves with clinical evidence of septicaemia, hypothermia, acute abdominal emergencies, and a history or clinical evidence of malnutrition.

Neonatal hypoglycemic brain injury is a cause of infantile spasms

Neonatal hypoglycemic brain injury is one of the causes of infantile spasms. In the present study, the clinical history and auxiliary examination results of 18 patients who developed infantile spasms several months after neonatal hypoglycemia were retrospectively analyzed. Among the 666 patients with infantile spasms admitted to two pediatric centers between January 2008 and October 2012, 18 patients developed infantile spasms after being diagnosed with neonatal hypoglycemia, defined as a whole blood glucose concentration of <2.6 mmol/l. These patients developed infantile spasms from between 2 and 10 months (mean, 4.9 months) following the diagnosis of neonatal hypoglycemia. All 18 patients had abnormal electroencephalographic findings with either classical or modified hypsarrhythmia. Upon examination using brain magnetic resonance imaging (MRI), 10 patients (55.6%) exhibited abnormalities. The MRI results principally showed a disproportional involvement of parietal and occipital cortices and sub-cortical white matter lesions. In conclusion, the results of this study indicate that neonatal hypoglycemic brain injury is associated with the subsequent development of infantile spasms.

Early term infants are at increased risk of requiring neonatal intensive care

BACKGROUND

Increasing evidence is demonstrating that infants born early on during the term period are at increased risk of morbidity compared with infants born closer to a complete 40 week gestational pregnancy. The purpose of this study was to compare early term [gestation age (GA): 37-37 6/7 weeks] neonatal outcomes with those of other full term neonatal intensive care unit (NICU) admissions.

METHODS

Retrospective chart review of all term infants admitted to the NICU at New York University Langone Medical Center over a 17 month period. Subjects were grouped and analyzed according to their GA at birth: 1) early term infants (GA between 37 0/7 to 37 6/7 weeks) and 2) other term infants (38 0/7 weeks and older).

RESULTS

Early term infants were more likely to require NICU care than other term infants [relative risk: 1.42, 95% confidence interval (CI)=1.07-1.88), P=0.01]. In the NICU, they are more likely to manifest respiratory distress syndrome [odds ratio (OR)=5.7, 95% CI=1.6-19.8, P<0.01] and hypoglycemia (OR=4.6, 95% CI=2.0-10.4, P<0.001). In addition, early term neonates were more likely to be born via elective cesarean section than other term neonates (OR=4.1, 95% CI=2.0-8.5, P<0.001).

CONCLUSIONS

Being born at early term is associated with increased risk of respiratory disease and hypoglycemia requiring neonatal intensive care. Further efforts directed at decreasing early term deliveries may be warranted.

Metabolic, endocrine, and other genetic disorders

Metabolic, endocrine, and genetic diseases of the brain include a very large array of disorders caused by a wide range of underlying abnormalities and involving a variety of brain structures. Often these disorders manifest as recognizable, though sometimes overlapping, patterns on neuroimaging studies that may enable a diagnosis based on imaging or may alternatively provide enough clues to direct further diagnostic evaluation. The diagnostic workup can include various biochemical laboratory or genetic studies. In this chapter, after a brief review of normal white-matter development, we will describe a variety of leukodystrophies resulting from metabolic disorders involving the brain, including mitochondrial and respiratory chain diseases. We will then describe various acidurias, urea cycle disorders, disorders related to copper and iron metabolism, and disorders of ganglioside and mucopolysaccharide metabolism. Lastly, various other hypomyelinating and dysmyelinating leukodystrophies, including vanishing white-matter disease, megalencephalic leukoencephalopathy with subcortical cysts, and oculocerebrorenal syndrome will be presented. In the following section on endocrine disorders, we will examine various disorders of the hypothalamic-pituitary axis, including developmental, inflammatory, and neoplastic diseases. Neonatal hypoglycemia will also be briefly reviewed. In the final section, we will review a few of the common genetic phakomatoses. Throughout the text, both imaging and brief clinical features of the various disorders will be discussed.

Pre-Adult MRI of Brain Cancer and Neurological Injury: Multivariate Analyses

Brain cancer and neurological injuries, such as stroke, are life-threatening conditions for which further research is needed to overcome the many challenges associated with providing optimal patient care. Multivariate analysis (MVA) is a class of pattern recognition technique involving the processing of data that contains multiple measurements per sample. MVA can be used to address a wide variety of neuroimaging challenges, including identifying variables associated with patient outcomes; understanding an injury's etiology, development, and progression; creating diagnostic tests; assisting in treatment monitoring; and more. Compared to adults, imaging of the developing brain has attracted less attention from MVA researchers, however, remarkable MVA growth has occurred in recent years. This paper presents the results of a systematic review of the literature focusing on MVA technologies applied to brain injury and cancer in neurological fetal, neonatal, and pediatric magnetic resonance imaging (MRI). With a wide variety of MRI modalities providing physiologically meaningful biomarkers and new biomarker measurements constantly under development, MVA techniques hold enormous potential toward combining available measurements toward improving basic research and the creation of technologies that contribute to improving patient care.

Hypoglycemia-induced alterations in hippocampal intrinsic rhythms: Decreased inhibition, increased excitation, seizures and spreading depression

Seizures are the most common clinical presentation of severe hypoglycemia, usually as a side effect of insulin treatment for juvenile onset type 1 diabetes mellitus and advanced type 2 diabetes. We used the mouse thick hippocampal slice preparation to study the pathophysiology of hypoglycemia-induced seizures and the effects of severe glucose depletion on the isolated hippocampal rhythms from the CA3 circuitry.

METHODS AND RESULTS

Dropping the glucose perfusate concentration from the standard 10 mM to 1 mM produced epileptiform activity in 14/16 of the slices. Seizure-like events (SLEs) originated in the CA3 region and then spread into the CA1 region. Following the SLE, a spreading-depression (SD)-like event occurred (12/16 slices) with irreversible synaptic failure in the CA1 region (8/12 slices). CA3 SD-like events followed ~30 s after the SD-like event in the CA1 region. Less commonly, SD-like events originated in the CA3 region (4/12). Additionally, prior to the onset of the SLE in the CA3 area, there was decreased GABA correlated baseline SPW activity (bSPW), while there was increased large-amplitude sharp wave (LASW) activity, thought to originate from synchronous pyramidal cell firing. CA3 pyramidal cells displayed progressive tonic depolarization prior to the seizure which was resistant to synaptic transmission blockade. The initiation of hypoglycemic seizures and SD was prevented by AMPA/kainate or NMDA receptor blockade.

CONCLUSIONS

Severe glucose depletion induces rapid changes initiated in the intrinsic CA3 rhythms of the hippocampus including depressed inhibition and enhanced excitation, which may underlie the mechanisms of seizure generation and delayed spreading depression.

Neural conduction impairment in the auditory brainstem and the prevalence in term babies in neonatal intensive care unit

OBJECTIVE

To detect neural conduction abnormality in the auditory brainstem in term babies in the neonatal intensive care unit (NICU), determine prevalence of the abnormality, and assess if maximum length sequence (MLS) technique improves early detection of the abnormality.

METHODS

One hundred and six term babies were recruited, and studied by recording and analysing MLS brainstem auditory evoked response (BAER). Interpeak intervals were analysed in detail, which were then compared with those in normal term babies.

RESULTS

Wave V latency and I-V and III-V intervals in MLS BAER were increased in the NICU term babies at all click rates 91-910/s, particularly at 455 and 910/s (p<0.05-0.001). No major abnormalities were found in wave I and III latencies and I-III interval. The abnormal increase in I-V and III-V intervals were seen in significantly more cases at 455 and 910/s in MLS BAER than at 21/s in conventional BAER (X(2)=10.92-13.88, all p<0.01). As a whole, 38 (35.8%) of the NICU babies had abnormal III-V and/or I-V intervals in MLS BAER, which was significantly more than 13 (12.2%) in conventional BAER (X(2)=16.14, p<0.01).

CONCLUSION

There is neural conduction impairment in the auditory brainstem in NICU term babies, which occurs in one-third of these babies.

SIGNIFICANCE

Term babies in NICU are at risk of neural conduction impairment in the auditory brainstem. High click rates in MLS BAER enhance early detection of the impairment.

Effect of insulin-induced hypoglycaemia on the central nervous system: evidence from experimental studies

Insulin-induced hypoglycaemia (IIH) is a major acute complication in type 1 as well as in type 2 diabetes, particularly during intensive insulin therapy. The brain plays a central role in the counter-regulatory response by eliciting parasympathetic and sympathetic hormone responses to restore normoglycaemia. Brain glucose concentrations, being approximately 15-20% of the blood glucose concentration in humans, are rigorously maintained during hypoglycaemia through adaptions such as increased cerebral glucose transport, decreased cerebral glucose utilisation and, possibly, by using central nervous system glycogen as a glucose reserve. However, during sustained hypoglycaemia, the brain cannot maintain a sufficient glucose influx and, as the cerebral hypoglycaemia becomes severe, electroencephalogram changes, oxidative stress and regional neuronal death ensues. With particular focus on evidence from experimental studies on nondiabetic IIH, this review outlines the central mechanisms behind the counter-regulatory response to IIH, as well as cerebral adaption to avoid sequelae of cerebral neuroglycopaenia, including seizures and coma.

Glucose control during labor and delivery

Neonatal hypoglycemia is an important consequence for the infant of the mother with diabetes. We have reviewed 24 published papers of various protocols for control of glucose in pregnant diabetic women during labor and delivery including our own published work. A relationship of maternal glucose during labor and neonatal hypoglycemia was sought in 19 of these studies. A significant inverse relationship was found in 10 reports with 3 others showing a similar trend. In all but 1 of these 13 studies the participants had pregestational diabetes. Three of the 6 studies not reporting an inverse relationship involved women with GDM. From this review it appears that the maternal glucose should be maintained between 4.0 and 6.0-7.0 mmol/L during labor. Most women with gestational diabetes, especially if they require <1.0 units/kg/d of insulin, can simply be monitored without intravenous insulin. Our own results demonstrate that a target glucose of 4.0-6.0 mmol/L can be used safely and results in a low rate of neonatal hypoglycemia using an iterative glucose insulin infusion protocol for women with pregestational diabetes and when needed for women with gestational diabetes.

Strategies to prevent reperfusion injury to the brain following intrapartum hypoxia-ischemia

Hypoxia-ischemia is an infrequent event which may occur prior to or during delivery, following a period of decreased placental and/or fetal blood flow. Following recovery, a reperfusion phase and secondary energy failure may occur 6-48 h subsequent to the initial insult. Therapeutic hypothermia may be offered to infants at risk for evolving encephalopathy if identified within the 6 h therapeutic window, and should be instituted as early as possible for eligible infants. Additionally, the clinician must pay close attention to supportive measures such as avoidance of hyperthermia, as well as comprehensive management of clinical or electrographic seizures, blood pressure, blood glucoses, and carbon dioxide levels.

Glycemic Control in Pediatric Patients on Extracorporeal Membrane Oxygenation

OBJECTIVES To determine whether glycemic control has an effect on outcomes for pediatric patients on extracorporeal membrane oxygenation (ECMO) therapy, while controlling for multiple factors.

METHODS A single-center retrospective chart review was performed on 82 patients who required ECMO from January 1, 2008, to December 31, 2010. All glucose concentrations collected while patients were on ECMO were analyzed; multiple other factors that may have affected mortality were also recorded. Primary outcome was mortality, and secondary outcomes were length of time on ECMO and length of time until death or discharge from the hospital.

RESULTS Of 82 patients, 53 patients survived ECMO (64.6%). Glucose control had no effect on survival of patients on ECMO (p=0.56), even when controlling for multiple factors (p=0.48). Similarly, statistical evaluation showed no differences for hospital mortality in relationship to controlled serum glucose (p=0.50). Patients with controlled glucose spent an average of 31.5% more time on ECMO than non-controlled patients (p=0.048).

CONCLUSIONS In this study, glycemic control, defined as serum glucose concentration between 60 mg/dL and 250 mg/dL for &gt;95% of the time on ECMO, had no statistically significant effect on mortality for patients on ECMO. Future studies could focus on tighter glucose control or specific dextrose/glucose protocols to evaluate whether improved glucose control would have an effect on morbidity and mortality.

Perinatal and early postnatal factors underlying developmental delay and disabilities

A delay in meeting developmental milestones may be secondary to perinatal events, involving complicated interactions between mother and fetus during delivery. Maternal factors including weight, diet, and morbidities can affect neonatal adaptation and later development. Prematurity, low birth weight, and previous intrauterine insults as well as complications during delivery of a previously normal fetus increase the risk for perinatal stress. In this article, the literature on perinatal and early postnatal factors that underlie risks for developmental delay and disabilities is reviewed. Studies that concern neuroprotective therapies and prediction of long-term neurologic outcome by clinical examination, neuroimaging techniques, and electroencephalographic studies are reviewed as well.

Topography of brain damage in metabolic hypoglycaemia is determined by age at which hypoglycaemia occurred

AIM

Having previously shown that comorbidity is a major determinant of neurological sequelae in hypoglycaemia, our aim was to describe the neuroimaging patterns of brain damage in different hypoglycaemic situations and to elucidate the factors that determine lesion topography.

METHOD

We reviewed 50 patients (31 females, 19 males) with symptomatic hypoglycaemia (<2.8 mmol/L) occurring between 1 day and 5 years of age (median 4 d) who had undergone magnetic resonance imaging (MRI; at least axial T2-weighted, sagittal T1-weighted, and coronal fluid-attenuated inversion recovery [FLAIR]-weighted imaging). MRI was performed during the follow-up examination at least 1 month after the occurrence of symptomatic hypoglycaemia, i.e. between 1 month and 5 years of age (median 3 mo). Hypoglycaemia resulted from three inborn errors of metabolism: congenital hyperinsulinism (33 patients), fatty acid β-oxidation disorders (13 patients), or glycogen storage disease type I (four patients). We selected the patients with clear MRI abnormalities and analysed their topography according to aetiology and age at occurrence of the lesion.

RESULTS

The topography of the brain lesions depended on age: from the neonatal period to 6 months of age, lesions predominantly involved the posterior white matter; between 6 and 22 months the basal ganglia, and after 22 months the parietotemporal cortex (p=0.04).

INTERPRETATION

The relationship between brain lesions and age could reflect the maturation sequence of the brain.

Comorbidity and metabolic context are crucial factors determining neurological sequelae of hypoglycaemia

AIM

To determine risk factors for neurological sequelae following hypoglycemia.

METHOD

We analysed the neurological outcome in 164 patients (mean age 10y 10mo, SD 5.9) following hypoglycemia due to three diseases with various metabolic contexts, different ages at onset, and combinations with comorbidity (fever/infection, hypoxia/ischemia): glycogen storage disease type I (GSDI) (21 patients, mean age at first hypoglycemic episode 3.8mo, SD 3.5); fatty acid β-oxidation defects (FAOD) (29 patients, mean age at first hypoglycemic episode 14.8mo, SD 12.6); and hyperinsulinism (HIns) (114 patients, mean age at first hypoglycemic episode 2.3mo, SD 4.7).

RESULTS

Risk factors of poor neurological outcome were aetiology (p<0.006), comorbidity (p<0.001), and prolonged convulsions (p<0.001). Ordinal logistic regression showed that comorbidity (p<0.001) and status epilepticus (p=0.002) were the main determinants of sequelae. Asymptomatic hypoglycemia did not lead to sequelae, whatever the aetiology. Age was not correlated to sequelae, whatever the aetiology. The highest prevalence of hypoglycemic sequelae was found in FAOD and HIns combined with comorbidity, the lowest in GSDI (p<0.001) in which hypoglycemia is often asymptomatic, associated with increased plasma lactate, and rarely combined with comorbidity.

INTERPRETATION

Hypoglycemia is severely deleterious for the brain in the context of fever/infection and/or hypoxia/ischemia, and status epilepticus. The metabolic context providing alternative fuels may improve neurological outcome.

Contribution of early glycemic status in the development of severe retinopathy of prematurity in a cohort of ELBW infants

OBJECTIVE

The objective of this study is to investigate the relationship between glycemic status and severe retinopathy of prematurity (ROP).

STUDY DESIGN

This is a retrospective cohort study of 114 infants <1000 g admitted to a level IV neonatal intensive care unit within 48 h of life. A cumulative, time-weighted glucose level (TWGL) derived from plotting glucose values over time was included in logistic regression analysis to identify predictors for severe ROP.

RESULT

Infants had 26.6 ± 2 weeks gestational age and had a birth weight of 782 ± 136 g. TWGL during first 10 and 30 days of life were greater in the severe ROP group (P<0.01). Unlike single events of glucose levels ≥ 150 mg dl(-1), 10 days TWGL ≥ 100 mg dl(-1) (odds ratio (OR) 5.2, P<0.02) and 30 days TWGL ≥ 118 mg dl(-1) (OR 5.7, P<0.02) were predictors for severe ROP (univariate). Multivariate regression confirmed 30 days TWGL ≥ 118 mg dl(-1) (OR 9.4 to 10) and gram-positive sepsis (OR 4.1 to 5) as predictors for severe ROP (P<0.05).

CONCLUSION

High overall glycemic status is associated with the development of severe ROP.

Long term prognosis of symptomatic occipital lobe epilepsy secondary to neonatal hypoglycemia

PURPOSE

To report on long-term clinical course in patients with symptomatic occipital lobe epilepsy secondary to neonatal hypoglycemia.

METHODS

Six patients with neonatal hypoglycemia and symptomatic occipital lobe epilepsy were studied in our hospital through reviewing their medical records retrospectively.

RESULTS

The median onset age of epilepsy was 2 years 8 months and median follow-up period was 12 years and 4 months. Initial seizure types were generalized convulsions in 4 patients, hemiconvulsion in 1, and infantile spasms in 1. Ictal manifestations of main seizures were identical to occipital lobe seizures, such as eye deviation, eye blinking, ictal vomiting, and visual hallucination. Seizure frequency was maximum during infancy and early childhood and decreased thereafter with no seizure in 2 patients, a few seizures a year in 3, and once a month in 1. All patients had status epilepticus in the early course of epilepsy. EEGs showed parieto-occipital spikes in all patients. MRI revealed cortical atrophy and T2 prolongation parieto-occipitally in 4 patients, hippocampal atrophy in 1, and unremarkable in 1.

CONCLUSION

This study indicates that epilepsy secondary to neonatal hypoglycemia is intractable during infancy and early childhood with frequent status epilepticus but tends to decrease in older age.