Effects of neonatal hypoglycaemia on the nervous system: a pathological study

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.

Further Delineation of Clinical Phenotype of ZMYND11 Variants in Patients with Neurodevelopmental Dysmorphic Syndrome

Intellectual disability with speech delay and behavioural abnormalities, as well as hypotonia, seizures, feeding difficulties and craniofacial dysmorphism, are the main symptoms associated with pathogenic variants of the ZMYND11 gene. The range of clinical manifestations of the ZMYND phenotype is constantly being expanded by new cases described in the literature. Here, we present two previously unreported paediatric patients with neurodevelopmental challenges, who were diagnosed with missense variants in the ZMYND11 gene. It should be noted that one of the individuals manifested with hyperinsulinaemic hypoglycaemia (HH), a symptom that was not described before in published works. The reason for the occurrence of HH in our proband is not clear, so we try to explain the origin of this symptom in the context of the ZMYND11 syndrome. Thus, this paper contributes to knowledge on the range of possible manifestations of the ZMYND disease and provides further evidence supporting its association with neurodevelopmental challenges.

Continuous interstitial glucose monitoring for term newborns: analysis of the first day of life

OBJECTIVE

Glycaemia in newborns changes significantly after birth; however, little is known about these changes. The objective was to describe continuous interstitial glucose values in term newborns who were exclusively breast fed on the first day of life.

DESIGN

We studied 159 newborns with appropriate weights for gestational age, who were exclusively breast fed on the first day of life, using a continuous glucose monitoring device that calculates interstitial glucose every 5 min. The device was removed after 24 hours, and the results were analysed using the R program, which provides the minimum, maximum, median and a standard curve with centiles.

RESULTS

At the second hour of life, the moment in which the sensor started to identify the newborn's glycaemia, interstitial glucose levels were 2.59-4.43 mmol/L (46.7-79.9 mg/dL). The median interstitial glucose level of the newborns during the first day of life was 3.33±0.48 mmol/L (60±8.6 mg/dL). Interstitial glucose levels dropped until the sixth hour of life, reaching 2.19-3.95 mmol/L (39.5-71.1 mg/dL), and then increased again. The maximum values were found at the 20th and 21st hours of life, which were 2.81-4.64 mmol/L (50.6-83.6 mg/dL).

CONCLUSION

The interstitial glucose during the first 24 hours of life declined until the sixth hour of life, then increased around the 20th hour and remained stable until the end of the first day of life.

Early neonatal hypoglycemia in term and late preterm small for gestational age newborns

BACKGROUND

Neonatal hypoglycemia is a common metabolic occurrence among small for gestational age (SGA) neonates. This study aims to determine the incidence of early neonatal hypoglycemia and confirms the potential risk factors among term and late preterm SGA neonates in a well-baby newborn nursery of a tertiary medical center in Southern Taiwan.

METHODS

We performed a retrospective medical record review of term and late preterm SGA (birth weight <10 percentile) neonates, born between January 1, 2012 and December 31, 2020, in the well-baby newborn nursery, of a tertiary medical center in Southern Taiwan. Blood glucose monitoring was routinely performed at 0.5, 1, 2, and 4 h of life. Antenatal and postnatal risk factors were recorded. Mean blood glucose level, age of occurrence, symptomatic hypoglycemia, and need for intravenous glucose treatment of early hypoglycemia in SGA neonates were documented.

RESULTS

690 SGA neonates in the nursery met the criteria and were retrospectively enrolled in the study, 358 of whom (51.80%) were male and 332 (48.10%) female. Of 690 enrolled SGA neonates, 134(19.42%) SGA neonates developed hypoglycemia during a well-baby nursery stay. Among these neonates, 97% of early hypoglycemic episodes occur during the first 2 h of life. The lowest blood glucose level was 46.78 ± 11.13 mg/dL, recorded in the first hour of life. Among the hypoglycemic 134 neonates, 26 (19.40%) neonates had to be transferred from the nursery to the neonatal ward and they required intravenous glucose treatment to achieve euglycemia. 14 (10.40%) neonates had symptomatic hypoglycemia. A multivariate logistic regression analysis revealed that cesarean delivery, small head circumference, small chest circumference, and low 1-min Apgar score were significant risk factors for early hypoglycemia in these neonates.

CONCLUSION

Periodic routine blood glucose level monitoring within the first 4 h of life in term and late preterm SGA neonates is required, especially those with cesarean delivery and low Apgar score.

Maximizing the detection rate of hypoglycemia among preterm neonates admitted in Neonatal intensive care unit in Ethiopia, 2021

The burden of hypoglycemia is high in resource limited countries, such as Ethiopia. However, there are no sufficient studies conducted in Ethiopia in general and in the study setting in particular in the previous era. Hence, this study aims to assess the proportion of hypoglycemia and associated factors among preterm neonates admitted to the neonatal intensive care unit at Debre Tabor Comprehensive Specialized Hospital, Ethiopia, in 2021. A hospital-based cross-sectional study was conducted from October 1 to December 30, 2021, at Debre Tabor Comprehensive Specialized Hospital in the neonatal intensive care unit ward. The data was entered in Epi-info 7 and exported to STATA version 14. A binary and multivariable logistic regression was computed at 95% confidence interval (CI). During bivariable analysis, variables having a p-value of less than 0.25 were chosen for multivariable logistic regression analysis, and variables having a p-value of less than 0.05 in multivariable analysis, were significant associations with the dependent variable. The study included 267 preterm neonates, and 23.59% (95% CI 18.9-29.1) were develop hypoglycemia. Moreover, 49 (18.35%) preterm neonates died during the study period. In this study, preterm neonates with hypothermia [Adjusted Odds Ratio (AOR = 4.5; 95 CI 3.4, 7.2)], birth asphyxia (AOR = 5.1; 95 CI 3.9, 27.1), seizure (AOR = 4.7; 95 CI 2.8, 17.8), and also preterm neonates born from diabetic mothers (AOR = 6.7; 95 CI 3.3, 27.2) were significantly associated with the occurrence of hypoglycemia in the neonatal intensive care. The proportion of hypoglycemia and associated factors among preterm neonates admitted to the neonatal intensive care unit at Debre Tabor Comprehensive Specialized Hospital was found to be high. The associated factors for the occurrence of hypoglycemia were discovered to be neonates with hypothermia, birth asphyxia, seizure, and neonates born with a diabetes mother. Thus, recognizing and treating the above associated factors is essential to preventing, and controlling hypoglycemia.

Associations between neonatal hypoglycaemia and brain volumes, cortical thickness and white matter microstructure in mid-childhood: An MRI study

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Neonatal hypoglycaemia is associated with damage to the brain in the acute phase.

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In mid-childhood, neonatal hypoglycaemia is associated with smaller brain regions.

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Deep grey matter regions such as the caudate and thalamus are implicated.

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Children with neonatal hypoglycemia had smaller occipital lobe cortical thickness.

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Grey matter may be especially vulnerable to long-term effects of neonatal hypoglycemia.

Neonatal hypoglycaemia is a common metabolic disorder that may cause brain damage, most visible in parieto-occipital regions on MRI in the acute phase. However, the long term effects of neonatal hypoglycaemia on the brain are not well understood. We investigated the association between neonatal hypoglycaemia and brain volumes, cortical thickness and white matter microstructure at 9–10 years.

Children born at risk of neonatal hypoglycaemia at ≥ 36 weeks’ gestation who took part in a prospective cohort study underwent brain MRI at 9–10 years. Neonatal hypoglycaemia was defined as at least one hypoglycaemic episode (at least one consecutive blood glucose concentration < 2.6 mmol/L) or interstitial episode (at least 10 min of interstitial glucose concentrations < 2.6 mmol/L). Brain volumes and cortical thickness were computed using Freesurfer. White matter microstructure was assessed using tract-based spatial statistics.

Children who had (n = 75) and had not (n = 26) experienced neonatal hypoglycaemia had similar combined parietal and occipital lobe volumes and no differences in white matter microstructure at nine years of age. However, those who had experienced neonatal hypoglycaemia had smaller caudate volumes (mean difference: −557 mm³, 95% confidence interval (CI), −933 to −182, p = 0.004) and smaller thalamus (−0.03%, 95%CI, −0.06 to 0.00; p = 0.05) and subcortical grey matter (−0.10%, 95%CI −0.20 to 0.00, p = 0.05) volumes as percentage of total brain volume, and thinner occipital lobe cortex (−0.05 mm, 95%CI −0.10 to 0.00, p = 0.05) than those who had not. The finding of smaller caudate volumes after neonatal hypoglycaemia was consistent across analyses of pre-specified severity groups, clinically detected hypoglycaemic episodes, and severity and frequency of hypoglycaemic events.

Neonatal hypoglycaemia is associated with smaller deep grey matter brain regions and thinner occipital lobe cortex but not altered white matter microstructure in mid-childhood.

Monitoring the Frequency and Duration of Hypoglycemia in Preterm Infants and Identifying Associated Factors

Hypoglycemia is common in very low birth weight neonates and may have adverse effects. Material and Method: Sixty preterm infants were monitored using continuous glucose monitoring (CGMS) and capillary techniques during the first week of life. Hypoglycemia was defined as glucose ≤47 mg/dL (≤2.6 mmol/L). Results: Hypoglycemic episodes were detected in 41.66% (95% CI: 29.07-55.12). In 69.64% the duration was greater than thirty minutes, in 26.78% (95% CI: 15.83-40.3) hypoglycemia exceeded two hours. Hypoglycemia was observed most frequently during the first 48 hours. In 35.7%, hypoglycemia was not detected with capillary tests. The agreement between the two techniques was good (r = 0.77, p < 0.001), Hypoglycemia was associated with a lower birth weight (OR: 0.99, p = 0.06). Conclusions: Hypoglycemia is frequent with significant duration in very low birth weight neonates. CGMS could be considered for use in these neonates to improve their glycemic control and prevent the associated morbidity.

Asymptomatic Hyperinsulinemic Hypoglycemia and Grade 4 Intraventricular Hemorrhage in a Late Preterm Infant

Hyperinsulinemic hypoglycemia (HH) has the potential to cause acute neurologic dysfunction and neurodevelopmental impairment. Parieto-occipital neuronal injuries have been reported in hypoglycemic infants, but intraparenchymal hemorrhage is rare. On day 5 of life, a late preterm infant was transferred to our care with recurrent asymptomatic hypoglycemia. Prior to arrival, plasma glucose levels were at a median of 1.25 mmol/L (22.5 mg/dL) in the first 6 hours of life, and he required a glucose infusion rate (GIR) of 22.6 mg/kg/min. Hyperinsulinism was confirmed in the presence of detectable insulin, low ketones, and fatty acid when hypoglycemic. A left grade 4 intraventricular hemorrhage (IVH) was noted in the cranial ultrasound scan during the workup for sepsis on the day of admission. However, magnetic resonance imaging of the brain on day 7 of life revealed extensive bilateral IVH. On day 9, he was initiated on diazoxide, and HH resolved within 48 to 72 hours, allowing increment of feeds while weaning GIR. Ventricular drain for post-hemorrhagic ventriculomegaly was advised but not performed. At 3 months, post-hemorrhagic ventriculomegaly was stable, and there were early signs of neurodevelopmental delay. After discontinuing diazoxide at 4 months of age, he passed an 8-hour fasting study confirming the resolution of HH. Severe hypoglycemia has been associated with cerebral hyperperfusion in preterm infants and potentially could cause IVH. Close monitoring and prompt intervention in preterm infants to prevent severe hypoglycemia are paramount. In addition to long-term neurodevelopmental follow-up, infants with recurrent hypoglycemia may benefit from neuroimaging and thereby early intervention if required.

Sanguinarine caused larval lethality and growth inhibition by suppressing energy metabolism in silkworms, Bombyx mori

Sanguinarine (Sang) is a natural alkaloid and distributed in several plants of Papaveraceae. The antitumor, antioxidant, antimicrobial and anti-inflammatory effects of Sang were extensively reported, but its speciality and mechanism against Lepidoptera insects were still unknown. In this study, detailed toxicological parameters of Sang against silkworms, Bombyx mori (B. mori), were determined by a toxicological test. Then, a nuclear magnetic resonance-based (NMR) metabolomics method was adopted to analyze the changes in hemolymph metabolites of silkworms after feeding Sang. The growth of fourth-instar larvae was significantly ceased by the oral administration of 0.05-0.3% Sang and vast deaths appeared in 0.3% Sang group on Day 4 and Day 5. The quantitative analysis of metabolites indicated that trehalose and citrate levels in hemolymph were increased after 24 h of feeding 0.3% Sang, whereas the concentrations of pyruvate, succinate, malate and fumarate were decreased. In addition, the enzymatic determination and reverse transcription quantitative PCR (RT-qPCR) showed that the trehalase (THL) activity and the transcriptional level of one gene coding THL were uniformly weakened by 0.3% Sang. One of the important mechanisms of Sang against silkworms might be interpreted as follows. Sang impaired trehalose hydrolysis, reduced THL activity and transcription, and led to the inhibition of energy metabolism, consequent antigrowth and high lethality in larvae of B. mori. Our findings offered new insights into the insecticidal effect of Sang from the perspective of energy metabolism and provided the basis for the application of Sang in the control of Lepidoptera pests.

Incidence of hypoglycemia in newborn infants identified as at risk

Background: Temporary low plasma glucose concentrations are common in healthy newborns. Although there is no uniform definition of neonatal hypoglycemia, there is a consensus in the current literature that plasma glucose concentrations should be measured in infants at risk. Known risk groups for transient neonatal hypoglycemia include infants of diabetic mothers (IDM), large (LGA) or small (SGA) for gestational age and late preterm (LPT) infants.Objectives: The aim of this retrospective trial was to determine the incidence of hypoglycemia and the impact of the application of a 2011 revised guideline in respect of additional feeding or i.v. glucose administration, admission to a neonatal ward and the number of blood samples taken.Methods: During the period 1 January 2015 to 31 January 2016, the plasma glucose concentrations of all infants at risk were determined. They were screened over a period of 24 hours or until plasma glucose concentration was >45 mg/dL on three occasions. Hypoglycemia was defined as a plasma glucose concentration <40 mg/dL, regardless of the age of the infant.Results: One hundred and thirty-six (13.6%) out of 1017 newborns were identified as at-risk patients, 119 (87.5%) of whom were included in the final data evaluation. Ten study participants had more than one risk factor and 32 (26.9%) newborns (male:female = 1.1:1) had a total of 40 hypoglycemic episodes. Three (9.4%) out of these 32 newborns had to be transferred to the neonatal ward for i.v. glucose treatment. The mean number of blood samples taken was 7.6 ± 2.4.Conclusions: The incidence of hypoglycemia in the studied infants at risk was 27%, and 19.7 blood samples had to be taken to detect one episode of low glucose concentration. Neonatal hypoglycemia can be recognized and avoided in time, which justifies the establishment of a standardized plasma glucose measurement protocol in newborn infants at risk.Brief RationaleFollowing a considerable number of sources, it is recommended that infants at risk be identified, low plasma glucose concentrations prevented and, if necessary, the affected neonates cared for. Our data show that the risk group for neonatal hypoglycemia comprised about one-tenth of all infants at our nursery and hypoglycemia occurred in one-fourth. These results are in accordance with the recommendations to implement this protocol as a screening tool in neonates.

A toxicological, metabonomic and transcriptional analysis to investigate the property of mulberry 1-deoxynojirimycin against the growth of Samia cynthia ricini

1-Deoxynojirimycin (DNJ) is a natural d-glucose analogue from mulberry with promising physiological activity in vivo. Up to the present, the antidiabetic effects of DNJ on lowering blood sugar and accelerating lipid metabolism in mammals were broadly reported, but the specific character of DNJ against insects was vastly ignored. In this study, a toxicological test of DNJ againgst eri-silkworm, Samia cynthia ricini was carried out to investigate the potential of DNJ in insect management. Further, a method of nuclear magnetic resonance (NMR) metabonomics and real-time qPCR (RT-qPCR) were performed to analyze the alteration in midgut of eri-silkworm caused by DNJ. The result of toxicology showed that 5% and 10% DNJ could significantly inhibit the development of third-instar larvae on day 1-5, and mass deaths happened in DNJ groups on day 3-5. The quantitative analysis of ¹H NMR in fifth-instar larvae showed that trehalose level increased in midgut of 0, 6 and 12 h DNJ groups, while the concentrations of glucose, lactate, alanine, pyruvate, α-ketoglutarate and fumarate were reduced in varying degrees. Meanwhile, principal component analysis (PCA) indicated that there were significant differences in the metabolic profiles among 12 h DNJ groups and the control group. In addition, RT-qPCR results displayed that four genes coding α-glucosidase, trehalase (THL) and lactate dehydrogenase (LDH) were lowered in expression of 12 h DNJ groups. Simultaneously, THL activity was significantly lowerd in 12 h DNJ groups. These mutually corroborated results indicated that the backbone pathways of energy metabolism, including hydrolysis of trehalose and glycogens, glycolysis and tricarboxylic acid (TCA) cycle were significantly inhibited by DNJ. Thus, the specific mechanism of DNJ efficiently suppressing the growth and energy metabolism of eri-silkworm was explored in this study, providing the potential of DNJ as to the production of botanical insecticide.

Forebrain cellular bioenergetics in neonatal mice

BACKGROUND

Hypoglycemia occurs frequently in the neonate and may result in neurologic dysfunction. Its impact on the kinetics of cellular respiration and bioenergetics in the neonatal brain remains to be explored.

AIMS

Develop murine model to investigate the effects of hypoglycemia on neonatal brain bioenergetics.

STUDY DESIGN

Forebrain fragments were excised from euthanized BALB/c pups aged <24 hours to 14 days. We measured cellular respiration (μM O2 min-1.mg-1) in phosphate-buffered saline with and without glucose, using phosphorescence oxygen analyzer, as well as cellular adenosine triphosphate (ATP, nmol.mg-1) using the luciferin-luciferase system.

RESULTS

In the presence of glucose, although cellular respiration was 11% lower in pups ≤3 days compared to those 3- 14 days old (0.48 vs. 0.54), that difference was not statistically significant (p = 0.14). Respiration driven by endogenous metabolic fuels (without added glucose) was 16% lower in pups ≤3 days compared to those 3- 14 days (0.35 vs. 0.42, p = 0.03), confirming their increased dependency on exogenous glucose. Although cellular ATP was similar between the two age groups (14.9 vs. 11.2, p = 0.32), the ATP content was more severely depleted without added glucose in the younger pups, especially in the presence of the cytochrome c oxidase inhibitor cyanide. The first-order rate constant of cellular ATP decay (hydrolysis) was 44% lower in 2-day-old pups compared to 14-day-old mice (0.43 vs. 0.77 min-1, p = 0.03).

CONCLUSIONS

Forebrain cellular respiration and ATP consumption are lower in young pups than older mice. In the absence of glucose, the support for these processes is reduced in young pups, explaining their brain hypersensitivity to hypoglycemia.

Moderate neonatal hypoglycemia and adverse neurological development at 2-6 years of age

To determine whether moderate neonatal hypoglycemia in otherwise healthy infants is associated with adverse neurodevelopmental outcome in pre-school children. Population-based cohort study with prospectively collected register data from Sweden. All singletons born July 1st 2008 through December 31st 2012 (n = 101,060) in the region were included. Infants with congenital malformations, infants treated in neonatal intensive care unit, infants with inborn errors of metabolism and infants to mothers with diabetes were excluded. Infants were followed-up until 2014, at 2–6 years of age. Exposure was neonatal moderate hypoglycemia. Main outcomes were a compiled neurological or neurodevelopmental outcome; any developmental delay; motor developmental delay; and cognitive developmental delay. In adjusted regression analyses, the odds ratio (OR) of any neurological or neurodevelopmental outcome was 1.48 (95% confidence interval: 1.17–1.88) in hypoglycemic compared to normoglycemic infants. The adjusted risk of any developmental delay was more than doubled (OR 2.53 [1.71–3.73]), the adjusted risk of motor developmental delay was almost doubled (OR: 1.91 [1.06–3.44]) and the adjusted risk of cognitive developmental delay was almost tripled (OR 2.85 [1.70–4.76]). Infants with early neonatal hypoglycemia (< 6 h) had a double risk (OR 1.94 [1.30–2.89]) of any neurological or neurodevelopmental outcome and a tripled risk of cognitive developmental delay (OR 3.17 [1.35–7.43]), compared to normoglycemic infants. In the first population-based study on this topic, we show that moderate neonatal hypoglycemia is associated with increased risks of impaired neurodevelopment. Current treatment routines for uncomplicated hypoglycemia should be followed.

Neonatal hypoglycemia: A wide range of electroclinical manifestations and seizure outcomes

PURPOSE

We examined the various types of epilepsy in children with neonatal hypoglycemia in order to define electroclinical and prognostic features of these patients.

METHOD

We retrospectively reviewed the medical records of patients with a history of symptomatic neonatal hypoglycaemia who have been followed at Gazi University Hospital Pediatric Neurology Department between 2006 and 2015. Patients with perinatal asphyxia were excluded. Details of each patient's perinatal history, neurological outcome, epilepsy details, seizure outcome and EEG and brain MRI findings were reviewed.

RESULTS

Fourty five patients (range 6 mo-15 y) with a history of symptomatic neonatal hypoglycaemia were included the study. Epilepsy developed in 36 patients and 23 of them had intractable epilepsy. All patients had occipital brain injury.

CONCLUSION

We observed that most of the patients, either manifesting focal or generalized seizures, further develop intractable epilepsy. This finding establishes neonatal hypoglycemia as a possible cause to be considered in any case of intractable epilepsy.

Association between antenatal corticosteroids and neonatal hypoglycemia in indicated early preterm births. J Matern Fetal Neonatal Med 2017;31:3095-3101. [PMID: 28782409 DOI: 10.1080/14767058.2017.1364724]

PURPOSE

We sought to determine if administration of antenatal corticosteroids in early preterm births (<34 weeks) is associated with an increased risk of developing neonatal hypoglycemia (<40 mg/dL) within the first 48 h of neonatal life.

MATERIALS AND METHODS

Retrospective cohort of all indicated singleton preterm births (23-34 weeks) in a single tertiary center from 2011 to 2014. The primary outcome was neonatal hypoglycemia (<40 mg/dL) within the first 48 h of life. The outcome was compared by antenatal corticosteroids received at any point during the gestation, within 2-7 d of delivery, and whether the patient received a partial, full, or repeat course of antenatal corticosteroids. Logistic regression was used to adjust for confounders.

RESULTS

Six hundred thirty-five patients underwent an indicated preterm birth during the study period. Six hundred and four (95%) received antenatal corticosteroids prior to delivery and 31 (5%) did not. The incidence of neonatal hypoglycemia within 48 h of life was not significantly different between those who received any antenatal corticosteroids and those who did not (23.0 versus 16.1%, adjusted odds ratio [OR] 1.3, 95%CI 0.5-3.6). Infants who received a full antenatal corticosteroid course within 2-7 d of delivery had similar incidences of hypoglycemia compared with those who received antenatal corticosteroids more than 7 d before delivery (20.4 versus 25.4%, adjusted OR 1.5, 95% confidence interval(CI) 0.8-2.9). Neonatal hypoglycemia was not increased by the number of antenatal corticosteroid doses (partial, full, or repeat course) administered. There was not a correlation between timing of antenatal corticosteroid administration before delivery, up to 250 h, and the lowest neonatal blood sugar in the first 48 h of life.

CONCLUSION

Our findings suggest antenatal corticosteroid administration in indicated early preterm infants (<34 weeks) may not increase the risk of developing neonatal hypoglycemia within the first 48 h of life. Further studies should validate our findings.

Metabolic changes in the midgut of Eri silkworm after Oral administration of 1-deoxynojirimycin: A 1H-NMR-based metabonomic study

1-deoxynojirimycin (DNJ) is a natural D-glucose analogue and has a strong physiological activity in inhibiting α-glucosidase in vivo. The antidiabetic effects of DNJ in mice or other mammals were extensively explored, but the physiological and toxic roles of DNJ in insects was seldom reported. In this study, the biological effects of DNJ were examined in midgut extracts of fourth-instar larvae of Eri silkworm (Samia cynthia ricini, Saturniidae). Based on nuclear magnetic resonance (NMR) metabonomics technology, we analyzed the alterations of glycometabolism, lipids, and energy metabolism pathways in the midgut of S. cynthia ricini caused by DNJ. Pattern recognition analysis (partial least square-discriminant analysis, PLS-DA) showed that four groups of latex, 0.25% DNJ, 0.5% DNJ and the mixture of 0.5% DNJ and latex (1:1) were distinctly different from the control group. Moreover, several metabolic pathways of DNJ-mediated modulation in the midgut were identified. Compared with the control group, alanine, succinate, glutamate, and fumarate concentrations decreased in three groups of 0.5% DNJ, latex, and the mixture, choline levels increased in two DNJ groups, and trehalose levels increased in all experimental groups. Therefore, these results suggest that DNJ modulated lipid metabolism by limiting the hydrolysis pathways of phospholipids metabolism. Additionally, DNJ has a potent negative effect on energy metabolism by inhibiting the hydrolysis of trehalose, glycolysis and the tricarboxylic acid (TCA) cycle. Overall, DNJ, as a single-ingredient, is an efficient substance for modulating lipid metabolism and inhibiting energy metabolism.

PEPCK-C reexpression in the liver counters neonatal hypoglycemia in Pck1 del/del mice, unmasking role in non-gluconeogenic tissues

Whole body cytosolic phosphoenolpyruvate carboxykinase knockout (PEPCK-C KO) mice die early after birth with profound hypoglycemia therefore masking the role of PEPCK-C in adult, non-gluconeogenic tissues where it is expressed. To investigate whether PEPCK-C deletion in the liver was critically responsible for the hypoglycemic phenotype, we reexpress this enzyme in the liver of PEPCK-C KO pups by early postnatal administration of PEPCK-C-expressing adenovirus. This maneuver was sufficient to partially rescue hypoglycemia and allow the pups to survive and identifies the liver as a critical organ, and hypoglycemia as the critical pathomechanism, leading to early postnatal death in the whole-body PEPCK-C knockout mice. Pathology assessment of survivors also suggest a possible role for PEPCK-C in lung maturation and muscle metabolism.

The Effects of Fluctuations in Blood Glucose Level on Reading Test Performance

This study examined the effect of fluctuations in blood glucose on the reading performance of diabetic school children. Nine diabetic children between the ages of 9 and 12 years were compared with a group of non-diabetics of the same ages and sex, who were matched on academic potential (by teacher judgement). The dependent variables were the vocabulary and reading comprehension subtests of the Canadian Test of Basic Skills. Although no achievement differences were found, differences were demonstrated in the time required to complete the subtests. The intercorrelations of achievement measures with blood glucose levels were also examined. The implications of these results, together with the limited existing literature, are discussed in terms of the directions needed in future research and the possible impact they might have on classroom practice.

Neonatal hypoglycemia

PURPOSE OF REVIEW

The screening and management for neonatal hypoglycemia remains a confusing and contentious problem in neonatology. The purpose of this article is to contrast recent recommendations from the American Academy of Pediatrics and the Pediatric Endocrine Society.

RECENT FINDINGS

Using different methodologies, the organizations have significant differences on whom to screen and what levels of glucose should be used for management. The identification of the first 48 h as a transitional hyperinsulinemic state is a new important concept. The neuroendocrine approach is contrasted with a neurodevelopmental strategy to find levels that exceed those associated with neuroglycopenia.

SUMMARY

The questions remain the same when it comes to screening and management of neonatal low-glucose levels. Recent outcome studies with differing results continue to add to the controversy as to what to do at the bedside. It is uncertain if universal screening of glucose levels in the first hours should be applied to all newborn infants. Persistent hypoglycemic syndromes must be identified prior to discharge.

A Cytotoxic, Co-operative Interaction Between Energy Deprivation and Glutamate Release From System xc- Mediates Aglycemic Neuronal Cell Death

The astrocyte cystine/glutamate antiporter (system xc(-)) contributes substantially to the excitotoxic neuronal cell death facilitated by glucose deprivation. The purpose of this study was to determine the mechanism by which this occurred. Using pure astrocyte cultures, as well as, mixed cortical cell cultures containing both neurons and astrocytes, we found that neither an enhancement in system xc(-) expression nor activity underlies the excitotoxic effects of aglycemia. In addition, using three separate bioassays, we demonstrate no change in the ability of glucose-deprived astrocytes--either cultured alone or with neurons--to remove glutamate from the extracellular space. Instead, we demonstrate that glucose-deprived cultures are 2 to 3 times more sensitive to the killing effects of glutamate or N-methyl-D-aspartate when compared with their glucose-containing controls. Hence, our results are consistent with the weak excitotoxic hypothesis such that a bioenergetic deficiency, which is measureable in our mixed but not astrocyte cultures, allows normally innocuous concentrations of glutamate to become excitotoxic. Adding to the burgeoning literature detailing the contribution of astrocytes to neuronal injury, we conclude that under our experimental paradigm, a cytotoxic, co-operative interaction between energy deprivation and glutamate release from astrocyte system xc(-) mediates aglycemic neuronal cell death.

Parieto-occipital encephalomalacia in children; clinical and electrophysiological features of twenty-seven cases

Context:

Brain injuries occurring at a particular time may cause damages in well-defined regions of brain. Perinatal hypoxic ischemic encephalopathy and hypoglycemia are some of the most common types of brain injuries. Neonatal hypoglycemia can cause abnormal myelination in parietal and occipital lobes resulting in parieto-occipital encephalomalacia. There is a small number of studies about clinical and electroencephalographic (EEG) features of children with parieto-occipital encephalomalacia. They might have important neurologic sequelae such as cortical visual loss, seizures, and psychomotor retardation.

Aims:

We aimed to evaluate the causes of parieto-occipital encephalomalacia and evaluate the clinical and electrophysiological features of children with parieto-occipital encephalomalacia.

Settings and Design:

We evaluated clinical features and EEGs of 27 children with parieto-occipital encephalomalacia.

Statistical Analysis Used:

Descriptive statistics were used.

Results:

Hospitalization during the neonatal period was the most common cause (88.9%) of parieto-occipital brain injury. Eleven patients (40.7%) had a history of neonatal hypoglycemia. Twenty-three patients (85.2%) had epilepsy and nine of the epileptic patients (39%) had refractory seizures. Most of the patients had bilateral (50%) epileptic discharges originating from temporal, parietal, and occipital lobes (56.2%). However, some patients had frontal sharp waves and some had continuous spike and wave discharges during sleep. Visual abnormalities were evident in 15 (55.6%) patients. Twenty-two (81.5%) had psychomotor retardation. Fine motor skills, social contact and language development were impaired more than gross motor skills.

Conclusions:

In our study, most of the patients with parieto-occipital encephalomalacia had an eventful perinatal history. Epilepsy, psychomotor retardation, and visual problems were common neurologic complications.

Astrocyte physiopathology: At the crossroads of intercellular networking, inflammation and cell death

Recent breakthroughs in neuroscience have led to the awareness that we should revise our traditional mode of thinking and studying the CNS, i.e. by isolating the privileged network of "intelligent" synaptic contacts. We may instead need to contemplate all the variegate communications occurring between the different neural cell types, and centrally involving the astrocytes. Basically, it appears that a single astrocyte should be considered as a core that receives and integrates information from thousands of synapses, other glial cells and the blood vessels. In turn, it generates complex outputs that control the neural circuitry and coordinate it with the local microcirculation. Astrocytes thus emerge as the possible fulcrum of the functional homeostasis of the healthy CNS. Yet, evidence indicates that the bridging properties of the astrocytes can change in parallel with, or as a result of, the morphological, biochemical and functional alterations these cells undergo upon injury or disease. As a consequence, they have the potential to transform from supportive friends and interactive partners for neurons into noxious foes. In this review, we summarize the currently available knowledge on the contribution of astrocytes to the functioning of the CNS and what goes wrong in various pathological conditions, with a particular focus on Amyotrophic Lateral Sclerosis, Alzheimer's Disease and ischemia. The observations described convincingly demonstrate that the development and progression of several neurological disorders involve the de-regulation of a finely tuned interplay between multiple cell populations. Thus, it seems that a better understanding of the mechanisms governing the integrated communication and detrimental responses of the astrocytes as well as their impact towards the homeostasis and performance of the CNS is fundamental to open novel therapeutic perspectives.

Hypoglycaemia and hypoxic-ischaemic encephalopathy

The transition from fetal to neonatal life requires metabolic adaptation to ensure that energy supply to vital organs and systems is maintained after separation from the placental circulation. Under normal conditions, this is achieved through the mobilization and use of alternative cerebral fuels (fatty acids, ketone bodies, and lactate) when blood glucose concentration falls. Severe hypoxia-ischaemia is associated with impaired metabolic adaptation, and animal and human data suggest that levels of hypoglycaemia that are tolerated under normal conditions can be harmful in association with hypoxia-ischaemia. The optimal target blood glucose level for ensuring adequate energy provision in hypoxic-ischaemic encephalopathy (HIE) remains unknown. However, recent data support guidance to maintain a blood glucose concentration of 2.5 mmol/L or more in neonates with signs of acute neurological dysfunction, which includes those with HIE, and this is higher than the accepted threshold of 2 mmol/L in infants without signs of neurological dysfunction or hyperinsulinism.

Real-time continuous glucose monitoring reduces the duration of hypoglycemia episodes: a randomized trial in very low birth weight neonates

OBJECTIVES

Hypoglycemia is frequent in very low birth weight (VLBW) neonates and compromises their neurological outcome. The aim of this study was to compare real-time continuous glucose monitoring system (RT-CGMS) to standard methods by intermittent capillary blood glucose testing in detecting and managing hypoglycemia.

STUDY DESIGN

Forty-eight VLBW neonates were enrolled in this prospective study. During their 3 first days of life, their glucose level was monitored either by RT-CGMS (CGM-group), or by intermittent capillary glucose testing (IGM-group) associated with a blind-CGMS to detect retrospectively missed hypoglycemia. Outcomes were the number and duration of hypoglycemic (≤ 50 mg/dl) episodes per patient detected by CGMS.

RESULTS

Forty-three monitorings were analyzed (IGM n = 21, CGM n = 22), with a median recording time of 72 hours. In the IGM group, blind-CGMS revealed a significantly higher number of hypoglycemia episodes than capillary blood glucose testing (1.2 ± 0.4 vs 0.4 ± 0.2 episode/patient, p<0.01). In the CGM-group, the use of RT-CGMS made it possible (i) to detect the same number of hypoglycemia episodes as blind-CGMS (1.2 ± 0.4 episode/patient), (ii) to adapt the glucose supply in neonates with hypoglycemia (increased supply during days 1 and 2), and (iii) to significantly reduce the duration of hypoglycemia episodes per patient (CGM 44[10-140] min versus IGM 95[15-520] min, p<0.05). Furthermore, it reduced the number of blood samples (CGM 16.9 ± 1.0 vs IGM 21.9 ± 1.0 blood sample/patient, p<0.001).

CONCLUSION

RT-CGMS played a beneficial role in managing hypoglycemia in VLBW neonates by adjusting the carbohydrate supply to the individual needs and by reducing the duration of hypoglycemia episodes. The clinical significance of the biological differences observed in our study need to be explored.

Flash visual evoked potentials are not specific enough to identify parieto-occipital lobe involvement in term neonates after significant hypoglycaemia

AIM

Hypoglycaemia is a significant problem in high-risk neonates and predominant parieto-occipital lobe involvement has been observed after severe hypoglycaemic insult. We explored the use of flash visual evoked potentials (FVEP) in detecting parieto-occipital lobe involvement after significant hypoglycaemia.

METHODS

Full-term neonates (n = 15) who underwent FVEP from January 2008 to May 2013 were compared with infants (n = 11) without hypoglycaemia or parietal-occipital lobe injury. Significant hypoglycaemia was defined as being symptomatic or needing steroids, glucagon or a glucose infusion rate of ≥12 mg/kg/min.

RESULTS

The hypoglycaemia group exhibited delayed latency of the first positive waveform on FVEP. The initial detected time for hypoglycaemia was later in the eight subjects with seizures (median 51-h-old) than those without (median 22-h-old) (P = 0.003). Magnetic resonance imaging showed that 80% of the hypoglycaemia group exhibited occipital-lobe injuries, and they were more likely to exhibit abnormal FVEP morphology (P = 0.007) than the controls. FVEP exhibited 100% sensitivity, but only 25% specificity, for detecting injuries to the parieto-occipital lobes.

CONCLUSION

Flash visual evoked potential (FVEP) was sensitive, but not sufficiently specific, in identifying parieto-occipital lobe injuries among term neonates exposed to significant hypoglycaemia. Larger studies exploring the potential role of FVEP in neonatal hypoglycaemia are required.

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.

Defining neonatal hypoglycaemia: a continuing debate

Hypoglycaemia is one of the most frequent metabolic problems in neonatal medicine, and maintaining glucose homeostasis is one of the important physiological events during fetal-to-neonatal transition. Although frequently observed transient low blood glucose concentrations in the majority of healthy newborns are the reflections of normal metabolic adaptation processes during this transition, there has been a genuine concern that prolonged or recurrent low blood glucose levels may result in acute systemic effects and long-term neurological and developmental consequences. Hence, it is not surprising that neonatal hypoglycaemia remains one of the most important issues in our day-to-day practice and that we also become obsessed with the numbers and values that we believe are a 'cut-off' for its definition. The aim of this article is to critically appraise some of the available evidence either to support or refute the most widely accepted definition of 'neonatal hypoglycaemia' (blood glucose concentration: <2.6 mmol/l or 47 mg/dl), to highlight our knowledge gaps in defining neonatal hypoglycaemia, and to address the important concept of using an 'operational threshold', rather than focusing too much on a single blood glucose cut-off value, which is often applied to all newborn infants.

Neurologic damage in hypoglycemia

Hypoglycemia occurs in diabetic patients as a consequence of treatment with hypoglycemic agents, in insulinoma patients as a result of excessive insulin production, and in infants as a result of abnormal regulation of metabolism. Profound hypoglycemia can cause structural and functional disturbances in both the central (CNS) and the peripheral nervous system (PNS). The brain is damaged by a short and severe episode of hypoglycemia, whereas PNS pathology appears after a mild and prolonged episode. In the CNS, damaged mitochondria, elevated intracellular Ca2(+) level, released cytochrome c to the cytosol, extensive production of superoxide, increased caspase-3 activity, release of aspartate and glutamate from presynaptic terminals, and altered biosynthetic machinery can lead to neuronal cell death in the brain. Considering the PNS, chronic hypoglycemia is associated with delayed motor and sensory conduction velocities in peripheral nerves. With respect to pathology, hypoglycemic neuropathy in the PNS is characterized by Wallerian-like axonal degeneration that starts at the nerve terminal and progresses to a more proximal part of the axon, and motor axons to the muscles may be more severely damaged than sensory axons. Since excitatory neurotransmitters primarily involve the neuron in the CNS, this "dying back" pattern of axonal damage in the PNS may involve mechanisms other than excitotoxicity.

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.

15-year follow-up of recurrent "hypoglycemia" in preterm infants

BACKGROUND

Observational study of 543 infants who weighed <1850 g, published in 1988 reported seriously impaired motor and cognitive development at 18 months in those with recurrent, asymptomatic hypoglycemia (plasma glucose level ≤2.5 mmol/L on ≥3 days). No study has yet replicated this observation.

AIM

To quantify disability in a similar cohort of children followed up throughout childhood.

POPULATION

All children born at <32 weeks' gestation in the north of England in 1990-1991 and had laboratory blood glucose levels measured daily for the first 10 days of life.

RESULTS

Forty-seven index children of the 566 who survived to 2 years had a blood glucose level of ≤2.5 mmol/L on ≥3 days. All of these children and hypoglycemia-free controls, matched for hospital of care, gestation, and birth weight, were assessed at age 2. No differences in developmental progress or physical disability were detected. The families were seen again when the children were 15 years old, and 38 of the index children (81%) and matched controls agreed to detailed psychometric assessment. Findings in the 2 groups were nearly identical (mean full-scale IQ: 80.7 vs 81.2). Findings in the 21 children with a level of ≤2.5 mmol/L on ≥4 days, 7 children with a level this low on 5 days, and 11 children with a level of <2.0 mmol/L on 3 different days did not alter these conclusions.

CONCLUSIONS

This study found no evidence to support the belief that recurrent low blood glucose levels (≤2.5 mmol/L) in the first 10 days of life usually pose a hazard to preterm infants.

Incidence of neonatal hypoglycemia in babies identified as at risk

OBJECTIVES

Routine blood glucose screening is recommended for babies at risk of neonatal hypoglycemia. However, the incidence of hypoglycemia in those screened is not well described. We sought to determine the incidence of hypoglycemia in babies identified as being at risk, and also to determine differences in incidence between at risk groups.

STUDY DESIGN

Infants (n = 514) were recruited who were born in a tertiary hospital, ≥35 weeks gestation and identified as at risk of hypoglycemia (small, large, infant of a diabetic, late-preterm, and other). Blood glucose screening used a standard protocol and a glucose oxidase method of glucose measurement in the first 48 hours after birth.

RESULTS

One-half of the babies (260/514, 51%) became hypoglycemic (<2.6 mM), 97 (19%) had severe hypoglycemia (≤2.0 mM), and 98 (19%) had more than 1 episode. The mean duration of an episode was 1.4 hours. Most episodes (315/390, 81%) occurred in the first 24 hours. The median number of blood glucose measurements for each baby was 9 (range 1-22). The incidence and timing of hypoglycemia was similar in all at risk groups, but babies with a total of 3 risk factors were more likely to have severe hypoglycemia.

CONCLUSIONS

Hypoglycemia is common amongst babies recommended for routine blood glucose screening. We found no evidence that screening protocols should differ in different at risk groups, but multiple risk factors may increase severity. The significance of these hypoglycemic episodes for long-term outcome remains undetermined.

Cot-side electroencephalography monitoring is not clinically useful in the detection of mild neonatal hypoglycemia

OBJECTIVES

To determine whether there is a relationship between electroencephalography patterns and hypoglycemia, by using simultaneous cot-side amplitude integrated electroencephalography (aEEG) and continuous interstitial glucose monitoring, and whether non-glucose cerebral fuels modified these patterns.

STUDY DESIGN

Eligible babies were ≥ 32 weeks gestation, at risk for hypoglycemia, and admitted to the neonatal intensive care unit. Electrodes were placed in C3-P3, C4-P4 O1-O2 montages. A continuous interstitial glucose sensor was placed subcutaneously, and blood glucose was measured by using the glucose oxidase method. Non-glucose cerebral fuels were measured at study entry, exit, and during recognized hypoglycemia.

RESULTS

A total of 101 babies were enrolled, with a median weight of 2179 g and gestation of 35 weeks. Twenty-four of the babies had aEEG recordings, and glucose concentrations were low (< 2.6 mM). There were 103 episodes of low glucose concentrations lasting 5 to 475 minutes, but no observable changes in aEEG variables. Plasma concentrations of lactate, beta-hydroxybutyrate, and glycerol were low and did not alter during hypoglycemia.

CONCLUSIONS

Cot-side aEEG was not useful for the detection of neurological changes during mild hypoglycemia. Plasma concentrations of non-glucose cerebral fuels were low and unlikely to provide substantial neuroprotection.

Neurochemical changes in the developing rat hippocampus during prolonged hypoglycemia

Hypoglycemia is common during development and is associated with the risk of neurodevelopmental deficits in human infants. The effects of hypoglycemia on the developing hippocampus are poorly understood. The sequential changes in energy substrates, amino acids and phosphocreatine were measured from the hippocampus during 180 min of insulin-induced hypoglycemia (blood glucose < 2.5 mmol/L) in 14-day-old rats using in vivo(1)H NMR spectroscopy. Hypoglycemia resulted in neuroglycopenia (brain glucose < 0.5 micromol/g). However, the phosphocreatine/creatine (PCr/Cr) ratio was maintained in the physiological range until approximately 150 min of hypoglycemia, indicating that energy supply was sufficient to meet the energy demands. Lactate concentration decreased soon after the onset of neuroglycopenia. Beyond 60 min, glutamine and glutamate became the major energy substrates. A precipitous decrease in the PCr/Cr ratio, indicative of impending energy failure occurred only after significant depletion of these amino acids. Once glutamate and glutamine were significantly exhausted, aspartate became the final energy source. N-acetylaspartate concentration remained unaltered, suggesting preservation of neuronal/mitochondrial integrity during hypoglycemia. Correction of hypoglycemia normalized the PCr/Cr ratio and partially restored the amino acids to pre-hypoglycemia levels. Compensatory neurochemical changes maintain energy homeostasis during prolonged hypoglycemia in the developing hippocampus.

Perioperative crystalloid and colloid fluid management in children: where are we and how did we get here?

It has been more than 50 yr since the landmark article in which Holliday and Segar (Pediatrics 1957;19:823-32) proposed the rate and composition of parenteral maintenance fluids for hospitalized children. Much of our practice of fluid administration in the perioperative period is based on this article. The glucose, electrolyte, and intravascular volume requirements of the pediatric surgical patient may be quite different than the original population described, and consequently, use of traditional hypotonic fluids proposed by Holliday and Segar may cause complications, such as hyperglycemia and hyponatremia, in the postoperative surgical patient. There is significant controversy regarding the choice of isotonic versus hypotonic fluids in the postoperative period. We discuss the origins of perioperative fluid management in children, review the current options for crystalloid fluid management, and present information on colloid use in pediatric patients.

Associated factors in neonatal hypoglycemic brain injury

Although associated factors are important for the occurrence of neural damage in neonatal hypoglycemia, they are not fully understood. Sixty patients with neonatal hypoglycemia were studied through a review of their medical records in Tottori University Hospital. The patients were classified into two main groups: Group I were patients who had mental retardation, developmental delay, cerebral palsy or epilepsy while Group II were those who were normal in their follow-up. Group I consisted of 12 patients while Group II consisted of 48 patients. The median gestational age was 38 weeks in Group I and 36.7 weeks in Group II. The frequencies of small for gestational age were similar in both groups. Blood glucose levels less than 15 mg/dl were more frequent in Group 1 (50.0%) than in Group 2 (14.6%) (P=0.015). Duration of hypoglycemia was longer in Group I (median, 14 h) than in Group II (median, 1.75 h) (p<0.001). The following factors were more frequent in Group I than in Group II: toxemia (33.3% and 8.3%, p=0.043), fetal distress (58.3% and 14.5%, p=0.004), an Apgar score of less than 5 at 1 min (33.3% and 6.4%, p=0.025), neonatal seizure (53.8% and 4.3%, p<0.001) and pathological jaundice (41.7% and 6.4%, p=0.006). Cranial CT or MRI revealed cerebral lesions in 8 of the 9 Group I patients in follow-up examinations. This study indicates that severe and prolonged neonatal hypoglycemia can cause cerebral lesions and other perinatal risk factors, such as hypoxia, neonatal seizure and pathological jaundice, would exacerbate hypoglycemic brain injuries.

Neurologic sequelae of neonatal hypoglycemia in Kayseri, Turkey

Contrary to belief, neonatal hypoglycemia is relatively common and can cause more severe neurological sequelae than is currently believed. Prevention of hypoglycemic brain damage by hindering prolonged and profound neonatal hypoglycemia might contribute to psychomotor development. At Erciyes University, between December 1996 and 2005, of the patients who applied to Paediatric Neurology Department, 60 cases with a history of neonatal hypoglycemia were included in the study. The magnetic resonance imaging (MRI) scans and clinical records of all patients were reviewed retrospectively. It was noted that the sequelae with glucose levels of 0 0 to 40 were more serious and intense. The same results were also observed in cranial MRI evaluation. In conclusion, intractable epilepsy, mental motor retardation, cerebral palsy, and visual disturbance were found to be the most common and severe conditions affecting sufferers of neonatal hypoglycemia. In the first 3 days of life, the close monitoring of patients at risk is critical, and hospitalization of severe cases should be considered.

Prevalence of structural central nervous system abnormalities in early-onset type 1 diabetes mellitus

OBJECTIVE

To characterize the effects of severe hypoglycemia on the developing brain in children with early-onset type 1 diabetes mellitus (T1DM).

STUDY DESIGN

Children diagnosed with T1DM before age 6 years were studied. Those with prospectively monitored severe hypoglycemia (coma/seizure; n = 32) were compared with age-matched peers (n = 30) with no history of such events using magnetic resonance imaging. Glycemic control (evaluated based on glycated hemoglobin [HbA(lc)] level), episodes of diabetic ketoacidosis (DKA), and clinical variables were monitored continuously since diagnosis in all subjects.

RESULTS

Mean HbA(lc) from diagnosis and the duration of T1DM were similar in those with and without a history of severe hypoglycemia (9.0% +/- 0.9% vs 8.8% +/- 0.9%; 7.2 +/- 2.7 years vs 6.7 +/- 2.3 years). A high prevalence of central nervous system (CNS) structural abnormalities was detected (29%), and mesial temporal sclerosis (MTS) was detected in 16% of the total sample (n = 62). The presence of MTS was not associated with a history of severe hypoglycemia or DKA. Analysis of brain matter volumes suggested relatively less gray matter density in those subjects with a history of severe hypoglycemia.

CONCLUSIONS

Early age of onset of T1DM per se is associated with a high incidence of CNS abnormalities, particularly MTS, suggesting hippocampal damage. Early-onset severe hypoglycemia may have an effect on gray matter volume.

Patterns of cerebral injury and neurodevelopmental outcomes after symptomatic neonatal hypoglycemia

BACKGROUND

Symptomatic neonatal hypoglycemia may be associated with later neurodevelopmental impairment. Brain injury patterns identified on early MRI scans and their relationships to the nature of the hypoglycemic insult and neurodevelopmental outcomes are poorly defined.

METHODS

We studied 35 term infants with early brain MRI scans after symptomatic neonatal hypoglycemia (median glucose level: 1 mmol/L) without evidence of hypoxic-ischemic encephalopathy. Perinatal data were compared with equivalent data from 229 term, neurologically normal infants (control subjects), to identify risk factors for hypoglycemia. Neurodevelopmental outcomes were assessed at a minimum of 18 months.

RESULTS

White matter abnormalities occurred in 94% of infants with hypoglycemia, being severe in 43%, with a predominantly posterior pattern in 29% of cases. Cortical abnormalities occurred in 51% of infants; 30% had white matter hemorrhage, 40% basal ganglia/thalamic lesions, and 11% an abnormal posterior limb of the internal capsule. Three infants had middle cerebral artery territory infarctions. Twenty-three infants (65%) demonstrated impairments at 18 months, which were related to the severity of white matter injury and involvement of the posterior limb of the internal capsule. Fourteen infants demonstrated growth restriction, 1 had macrosomia, and 2 had mothers with diabetes mellitus. Pregnancy-induced hypertension, a family history of seizures, emergency cesarean section, and the need for resuscitation were more common among case subjects than control subjects.

CONCLUSIONS

Patterns of injury associated with symptomatic neonatal hypoglycemia were more varied than described previously. White matter injury was not confined to the posterior regions; hemorrhage, middle cerebral artery infarction, and basal ganglia/thalamic abnormalities were seen, and cortical involvement was common. Early MRI findings were more instructive than the severity or duration of hypoglycemia for predicting neurodevelopmental outcomes.

Neurologic outcome in patients with MRI pattern of damage typical for neonatal hypoglycemia

Imaging features of infants who suffered from brain damage as a result of neonatal hypoglycemia were shown to have similar patterns, and to affect the parietal and occipital lobes most severely. Long term follow up regarding clinical outcome of patients with neonatal hypoglycemia and this pattern of damage are limited. We reviewed the medical records of 24 patients with typical neuroimaging features seen following neonatal hypoglycemia; we report neurological outcome in 13 of them who have documented hypoglycemia. Except for one patient, all patients had prenatal and perinatal problems including prematurity, perinatal hypoxia, intrauterine growth retardation, sepsis, indirect hyperbilirubinemia. All but one patient had symptomatic partial epilepsy, five of them were medically intractable. Other neurologic problems included developmental delays, learning and behavior problems, hyperactivity and attention difficulties, autistic features, microcephaly and cortical blindness. We conclude that early diagnosis and treatment of neonatal hypoglycemia is crucial to prevent future neurological sequelae, especially in patients with additional perinatal risk factors.

Plasma glucose concentrations in profound neonatal hypoglycemia

The study goal was to define low thresholds of plasma glucose concentrations that constitute profound hypoglycemia. Population analysis was performed on research publications on neonatal hypoglycemia ascertained by a Medline search. Eligible patients had neurological sequelae associated directly and primarily with hypoglycemia (profound hypoglycemia). Of 89 infants, more than 95% had plasma glucose levels of less than 25 mg/dL that were first detected at more than 10 hours of age. A breakdown of study patients according to those with or without neurological sequelae, who were exposed to a similar degree of hypoglycemia, showed a combined incidence of neurological injury of 21%, with 95% confidence interval from 14% to 27%.

Neurodevelopment after neonatal hypoglycemia: a systematic review and design of an optimal future study

OBJECTIVE

Our goal was to assess the effect of episodes of neonatal hypoglycemia on subsequent neurodevelopment.

METHODS

We searched Medline and Embase for cohort studies on subsequent neurodevelopment after episodes of hypoglycemia in the first week of life. Reference lists of available studies were reviewed, and content experts were contacted for additional studies. Included studies were selected and appraised for methodologic quality by 2 reviewers. Methodologic quality was assessed according to well-accepted criteria for prognostic studies. Eventually, all studies were given an overall quality score: poor, moderate, or high quality. Studies in the latter 2 categories were considered for quantitative data analysis.

RESULTS

Eighteen eligible studies were identified. The overall methodologic quality of the included studies was considered poor in 16 studies and high in 2 studies. Pooling of results of the 2 high-quality studies was deemed inappropriate because of major clinical and methodologic heterogeneity. None of the studies provided a valid estimate of the effect of neonatal hypoglycemia on neurodevelopment. Building on the strengths and weaknesses of existing studies, we developed a proposal for an "optimal" future study design.

CONCLUSIONS

Recommendations for clinical practice cannot be based on valid scientific evidence in this field. To assess the effect of neonatal hypoglycemia on subsequent neurodevelopment, a well-designed prospective study should be undertaken. We submit a design for a study that may answer the still-open questions.

Neonatal hypoglycemia and occipital cerebral injury

Occipital brain injury associated with neonatal hypoglycemia can result in long-term disability, epilepsy, and visual impairment. The etiology of this pattern of injury is unclear; however, transient hyperinsulinism may be an independent risk factor. Magnetic resonance brain imaging can delineate the extent of brain injury and guide follow-up.

Hypoglycemia in newborn infants: Features associated with adverse outcomes

The purpose of this review article is to document from the literature values of blood/plasma glucose concentration and associated clinical signs and conditions in newborn infants (both term and preterm) that indicate a reasonable clinical probability that hypoglycemia is a proximate cause of acute and/or sustained neurological injury and to review the physiological and pathophysiological responses to hypoglycemia that may influence the ultimate outcome of newborns with low blood glucose. Our overall conclusion is that there is inadequate information in the literature to define any one value of glucose below which irreparable hypoglycemic injury to the central nervous system occurs, at any one time or for any defined period of time, in a population of infants or in any given infant. Clinical signs of prolonged and severe neurological disturbance (coma, seizures), extremely and persistently low plasma/blood glucose concentrations (0 to <1.0 mmol/l [0 to <18-20 mg/dl] for more than 1-2 h), and the absence of other obvious central nervous system (CNS) pathology (hypoxia-ischemia, intracranial hemorrhage, infection, etc.) are important for the diagnosis of injury due to glucose deficiency. Specific conditions, such as persistent hyperinsulinemia with severe hypoglycemic episodes that include seizures, also contribute to the diagnosis of hypoglycemic injury. Such lack of definitive measures of injury specific to glucose deficiency indicates that clinicians should be on the alert for infants at risk of hypoglycemia and for clinical signs and conditions that might herald severe hypoglycemia; they should have a low threshold for investigating and diagnosing 'hypoglycemia' with frequent measurements of plasma/blood glucose concentration; and they should treat low glucose concentrations promptly and maintain them in a safe range. Because there is no conclusive evidence or consensus in the literature that defines an absolute value or duration of 'hypoglycemia' that must occur, with our without related clinical complications, to produce neurological injury, clinicians should consider the information currently available, determine a 'target' plasma or blood glucose concentration that is acceptable, and treat infants with glucose concentrations below this value accordingly. Our intent in this review article is to highlight the studies relevant to this issue and help clinicians formulate a safe and, hopefully, effective strategy for the diagnosis and treatment of hypoglycemia.

Neonatal hypoglycaemic encephalopathy: diffusion-weighted imaging and proton MR spectroscopy

We report two infants with neonatal hypoglycaemic encephalopathy who were evaluated with diffusion-weighted imaging (DWI) and proton MR spectroscopy (MRS) as well as conventional MR. As in conventional MR, DWI and proton MRS revealed a predominance of abnormalities in the parieto-occipital lobes and underlying white matter including the splenium of the corpus callosum. In the acute phase of the disease, lesions on DWI showed restricted water diffusion and on DWI the characteristic lesions seemed to be more readily discernible than on conventional MRI. In the chronic phase, DWI demonstrated increased water diffusion in the affected areas showing atrophy on conventional MRI. Proton MRS revealed an increased lactate-lipid peak and a decreased NAA peak in the involved areas. DWI and proton MRS findings appear helpful in evaluating the extent and the presence of neuronal damage early in the course of neonatal hypoglycaemic encephalopathy.

Brain imaging findings in neonatal hypoglycemia: case report and review of 23 cases

A hypoglycemic infant with secondary occipital brain injury defined by serial computed tomography and magnetic resonance imaging is described. An additional 22 similar cases were previously published in the English language literature. A total of 23 cases (including the present case) were reviewed. Abnormal brain imaging findings are associated with profound hypoglycemia and show involvement of the occipital lobes in 82% of affected newborns. Half of these infants had visual impairment, and their median and range of plasma glucose values, and postnatal age when hypoglycemia was first detected, were 7 mg/dL (range, 2-26 mg/dL) and 48 hours (range, 1-72 hours), respectively.