Infant malnutrition affects cortical auditory evoked potentials

The effect of early versus late lipid infusion in parenteral nutrition on the biochemical and cortical auditory evoked potential parameters in preterm neonates

Background

As brain activity depends greatly on the functions provided by lipid membranes, dietary fat in early life can affect the developing nervous system. Despite the adoption of an early more aggressive parenteral nutrition approach with amino acid infusions still reluctance to the early use of intravenous lipids in neonates.

Aim

To compare the effect of delayed versus early introduction of intravenous lipid in preterm on the biochemical parameters and on brain development by the cortical auditory evoked potential (CAEP) latency and amplitude.

Methods

This is a comparative study included 49 neonates admitted at the ain shams university NICUs. Participants were divided into two groups: 26 in group of early lipid infusion and 23 in late lipid infusion, Demographic data, and biochemical parameters were documented during the 1st 2 weeks of life. The CAEP was performed at age of 6 months. The latency and amplitude of P1 were recorded and compared between both groups.

Results

In the present work we found that group of early lipid infusion had reach their full oral intake earlier with shorter duration of parenteral nutrition and length of stay. They had better weight gain and significantly better glucose level control than group of late lipid infusion. There was no significant difference in the other chemical parameters between both groups expect for the higher incidence of cholestasis in the group of late lipid infusion. At 6 months of age, the group of early lipid infusion had significantly shorter latency and amplitude of P1 than the group of late lipid infusion.

Conclusion

Early effective nutrition positively affect feeding tolerance and weight gain and maturation of higher brain centers brain.

Long latency auditory evoked potentials in malnourished children

PURPOSE

To characterize the findings obtained in the long latency auditory evoked potentials in malnourished children, as well as to compare them to the results obtained for children at the same age who present typical development.

METHODS

Sixty-five children aged between 7 and 12 years old, of both genders, were evaluated. The control group consisted of 34 children with normal development and the study group consisted of 31 children diagnosed with malnutrition. All children underwent conventional pure tone audiometry, acoustic impedance measurement, dichotic digit test and long latency auditory evoked potentials.

RESULTS

The study group presented a statistically significant difference for latencies of the components P1, N1 and P300. The latencies of these components were higher than those of the control group. Concerning the types of alterations found in the study group, increased latency for P1 and P300 and the absence of response in N1 were predominant. The control group showed a statistically significant difference in the amplitude of P300 when compared to the right and left ears.

CONCLUSION

Malnourished children present with changes in the long latency auditory evoked potentials, suggesting a deficit in central auditory pathways and alterations in the processing of acoustic information.

Assessment of neurodisability and malnutrition in children in Africa

Neurodevelopmental delay, neurodisability, and malnutrition interact to contribute a significant burden of disease in global settings. Assessments which are well integrated with plans of management or advice are most likely to improve outcomes. Assessment tools used in clinical research and programming to evaluate outcomes include developmental and cognitive tools that vary in complexity, sensitivity, and validity as well as the target age of assessment. Few tools have been used to measure socioemotional outcomes and fewer to assess the disabled child with malnutrition. There is a paucity of tools used clinically which actually provide families and professionals with advice to improve outcomes. Brain imaging, electroencephalography, audiology, and visual assessment can also be used to assess the effect of malnutrition on brain structure and function. The interaction of neurodisability and malnutrition is powerful, and both need to be considered when assessing children. Without an integrated approach to assessment and management, we will not support children and families to reach their best potential outcomes.

Physiological slowing and upregulation of inhibition in cortex are correlated with behavioral deficits in protein malnourished rats

Protein malnutrition during early development has been correlated with cognitive and learning disabilities in children, but the neuronal deficits caused by long-term protein deficiency are not well understood. We exposed rats from gestation up to adulthood to a protein-deficient (PD) diet, to emulate chronic protein malnutrition in humans. The offspring exhibited significantly impaired performance on the 'Gap-crossing' (GC) task after reaching maturity, a behavior that has been shown to depend on normal functioning of the somatosensory cortex. The physiological state of the somatosensory cortex was examined to determine neuronal correlates of the deficits in behavior. Extracellular multi-unit recording from layer 4 (L4) neurons that receive direct thalamocortical inputs and layers 2/3 (L2/3) neurons that are dominated by intracortical connections in the whisker-barrel cortex of PD rats exhibited significantly low spontaneous activity and depressed responses to whisker stimulation. L4 neurons were more severely affected than L2/3 neurons. The response onset was significantly delayed in L4 cells. The peak response latency of L4 and L2/3 neurons was delayed significantly. In L2/3 and L4 of the barrel cortex there was a substantial increase in GAD65 (112% over controls) and much smaller increase in NMDAR1 (12-20%), suggesting enhanced inhibition in the PD cortex. These results show that chronic protein deficiency negatively affects both thalamo-cortical and cortico-cortical transmission during somatosensory information processing. The findings support the interpretation that sustained protein deficiency interferes with features of cortical sensory processing that are likely to underlie the cognitive impairments reported in humans who have suffered from prolonged protein deficiency.

Auditory brainstem potentials in children with protein energy malnutrition

OBJECTIVE

In this study, auditory brainstem potentials (ABPs) were studied in children with protein energy malnutrition (PEM) to determine the effects of PEM on the developing brain in children.

METHODS

A total of 31 children, aged 3-36 months with moderate/severe PEM and 25 healthy children, aged 3-48 months were included in the study. Nutritional status of the children was assessed by the Gomez classification. Recordings of ABPs were performed by using Nihon Kohden Neuropack 2 device.

RESULTS

Of 31 children, 22 (71%) had severe malnutrition, 9 (29%) had moderate malnutrition. Additionally, 8 (26%) and 9 (29%) children had iron deficiency anemia and hypoalbuminemi, respectively. There were significant differences in the mean latencies of the waves I-V on the right and left ears and in the mean interpeak latencies (IPLs) of the waves III-V and I-V on the right ear between the study and control groups (P<0.05). The mean IPLs of I-V on the left side were found to be longer in the moderate PEM group than those of severe PEM group (P<0.05). There was not any difference between the groups of PEM with low serum albumin and PEM with normal serum albumin. While the mean IPLs of I-III on the right side were found longer in the cases of PEM without iron deficiency anemia, the mean latency of wave I on the left side, and the mean IPLs of III-V on the right side were longer in the children with PEM plus iron deficiency anemia (P<0.05).

CONCLUSIONS

Our findings showed that children with moderate/severe PEM had ABPs abnormalities in different degrees, which reflect defects in myelination of auditory brainstem pathways in children with moderate/severe PEM. However, we found contradictory results between abnormalities in ABPs and degree of malnutrition and iron deficiency anemia. We think that more extensive studies should be performed to determine whether or not there was a relationship between these parameters.

An event-related potential study of older children with an early history of failure to thrive

Elementary and junior high school children (n = 13), who were diagnosed with nonorganic failure to thrive (FTT) as infants and toddlers, were compared with a normal control group (n = 14) on visual event-related potentials (ERPs) elicited during a primed lexical decision task. Positive stimuli were real words that were identical to the priming stimuli; negative stimuli were nonpronounceable letter strings. Although the groups did not differ in word-list reading level, the former FTT group had slower reaction (decision) times and did not show ERP evidence of priming in the N400 epoch. Anterior sites yielded better separation of the real words and letter strings than posterior sites. A late anterior component between 500 msec to 650 msec poststimulus onset showed the largest condition effect for both groups. The control group had a larger negative going late anterior component to words than the FTT group. The combined reaction time and ERP findings point to less automatized word recognition in the FTT group.

An electrophysiological study of school-aged children with a history of failure to thrive during infancy

Sixty-five subjects, ages 8 to 12, participated in a visual electrophysiological study. Twenty-two of the subjects had received a diagnosis of nonorganic failure-to-thrive (FTT) before the age of three. The remaining 43 subjects had no history of FTT and served as Controls. IQs were obtained with the abbreviated WISC-III, and the Controls were split into two groups, LO IQ and HI IQ, to provide a LO IQ Control group with an average IQ equivalent to the FTT group. Event-related brain potentials (ERPs) were recorded from five scalp locations during a cued continuous performance task (CPT). Subjects had to press a button every time they saw the letter "X" following the letter "A" (50 targets out of 400 stimuli). During the CPT, the FTT subjects made marginally more errors of omission to targets than the LO IQ Control group and significantly more errors of omission than the HI IQ Control subjects. The groups did not differ significantly on errors of commission (false alarms) or reaction times to targets. ERP averages revealed a group difference in amplitude in a late slow wave for the 50 non-X stimuli (false targets) that followed the letter A. This difference was greatest over frontal sites, where the FTT group had a more negative going slow wave than each control group. Late frontal negativity to No Go stimuli has been linked with post-decisional processing, notably in young children. Thus, the FTT subjects may have less efficient inhibitory processes, reflected by additional late frontal activation.