Motor nerve conduction velocity in very preterm infants

Corrosion mitigation of mild steel in hydrochloric acid solution using grape seed extract

Plant extracts have gained a lot of attention due to their ecofriendly nature for corrosion inhibition. In this study, we examined the inhibition performance of grape seed extract as an eco-environmental inhibitor for mild steel in hydrochloric acid medium. Electrochemical impedance spectroscopy, potentiodynamic polarization, and electrochemical noise techniques were employed to study mild steel's electrochemical behavior in the hydrochloric acid solutions containing grape seed extract. Results depicted that grape seed extract could successfully inhibit the corrosion of mild steel. Besides, water droplet contact angle, field-emission scanning electron microscopy coupled with energy dispersive spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy were utilized to study the surface of mild steel specimens after dipping in acidic solutions. Electrochemical impedance results showed a corrosion efficiency of about 88% in 300 ppm of grape seed extract. Also, results revealed more compact corrosion products with improved integrity in the presence of grape seed, which confirmed electrochemical test results.

Utility and practice of electrodiagnostic testing in the pediatric population: An AANEM consensus statement

Nerve conduction studies and needle electromyography, collectively known as electrodiagnostic (EDX) studies, have been available for pediatric patients for decades, but the accessibility of this diagnostic modality and the approach to testing vary significantly depending on the physician and institution. The maturation of molecular diagnostic approaches and other diagnostic technologies such as neuromuscular ultrasound indicate that an analysis of current needs and practices for EDX studies in the pediatric population is warranted. The American Association of Neuromuscular & Electrodiagnostic Medicine convened a consensus panel to perform literature searches, share collective experiences, and develop a consensus statement. The panel found that electrodiagnostic studies continue to have high utility for the diagnosis of numerous childhood neuromuscular disorders, and that standardized approaches along with the use of high-quality reference values are important to maximize the diagnostic yield of these tests in infants, children, and adolescents.

Neuromuscular maturation in the neonate: Combined electroneurographic and ultrasonographic study

BACKGROUND

The combined electroneurography and muscle ultrasound examination (ENG-USM) in adult patients showed a correlation between the compound motor action potential (CMAP) and muscular thicknesses (MT). No similar studies exist regarding the neonatal period.

AIM

To evaluate the correlations between the maximum compound muscle action potential (CMAP) and maximum muscle thickness (MT) in term and premature newborns versus a group of young adults, as measured by combined electroneurography-ultrasonography (ENG-USM) to assess the stages.

STUDY DESIGN

Observational cohort study.

SUBJECTS

We studied 36 subjects (14 premature and 11 term infants, and 11 young adults), who underwent ENG-USM of the tibialis anterioris (TA) muscle.

OUTCOME MEASURES

We measured: 1) Onset-Peak (O-P) and Peak-to-Peak (P-P) maximum CMAP; 2) maximum MT; and 3) MT at the detected maximum CMAP.

RESULTS

The maximum CMAP in term newborns studied was about 1/3 of the mean value measured in the adults; the differences between O-P and P-P values of the term versus premature infants were not significant. We did not find a good correlation between maximum MT and maximum CMAP in the term (r = 0.63) newborns, contrary to what was found in preterms (r = 0.95) and in young adults (r = 0.98).

CONCLUSION

Our ENG-USM study shows that in newborns, the site of innervation of the neuromuscular plaque does not correspond to MT since muscle growth is related to the period of development, and depends on the progression of the nerve terminal branches that go to innervate the same muscle.

Peripheral nervous system maturation in preterm infants: longitudinal motor and sensory nerve conduction studies

OBJECTIVE

To study the evolution of sensory-motor nerves in the upper and lower limbs in neurologically healthy preterm infants and to use sensory-motor studies to compare the rate of maturation in preterm infants at term age and full-term healthy neonates.

METHODS

The study comprised 26 neurologically normal preterm infants born at 23-33 weeks of gestational age, who underwent sensory nerve conduction and motor nerve conduction studies from plantar medial and median nerves and from tibial and ulnar nerves, respectively. We repeated the same neurophysiological studies in 19 of the preterm infants every 2 weeks until postnatal term age. The data from the preterm infants at term was matched with a group of ten full-term babies a few days after birth.

RESULTS

The motor nerve conduction velocity of the tibial and ulnar nerves showed progressive increases in values in relation to gestational age, but there was a decrease of values in distal latencies and F wave latencies. Similarly, there was a gradual increase of sensory nerve conduction velocity values of the medial plantar and median nerves and decreases in latencies in relation to gestational age. At term age, the preterm infants showed significantly lower values of conduction velocities and distal latencies than the full-term neonates. These results were probably because the preterm infants had significantly lower weights, total length and, in particular, distal segments of the limbs at term age.

CONCLUSION

The sensory-motor conduction parameters were clearly related to gestational age, but extrauterine life did not affect the maturation of the peripheral nervous system in the very preterm babies who were neurologically healthy.

Maternal Thyroid Function During Pregnancy and the Child's Linguistic and Sensory Development in the Northern Finland Birth Cohort 1986

BACKGROUND

Maternal hypothyroidism and hypothyroxinemia are associated with poor neuropsychological development in children. Previous research is lacking on whether maternal thyroid dysfunction affects sensory and linguistic development in childhood.

METHODS

The Northern Finland Birth Cohort 1986 included all births within a year (9,362 women, 9,479 children) from the two northernmost Finnish provinces. Maternal serum samples (n = 5,791) were obtained in early pregnancy and analyzed for TSH, free T4, and thyroid peroxidase antibodies (TPO-Abs). Five thousand three hundred and ninety-one parents evaluated their child's sensory and linguistic development at 7 years old via a questionnaire (excluding children with an intelligence quotient ≤85). The prevalence of sensory and linguistic impairments was compared between mothers with and without thyroid dysfunction.

RESULTS

There were no statistically significant differences in the prevalence of sensory or linguistic impairment between children of mothers with and without thyroid dysfunction. Children of hypothyroid and hypothyroxinemic mothers had an increased prevalence of vision impairment compared with those of euthyroid mothers (10.8 and 11.7%, respectively, versus 6.5%), but the difference was not significant. All results remained similar after excluding TPO-Ab-positive mothers and premature children.

CONCLUSION

We did not find an association between maternal thyroid dysfunction during pregnancy and sensory and linguistic development impairment in childhood. A somewhat higher prevalence of vision impairment was seen in children of hypothyroid and hypothyroxinemic mothers, which merits further research.

Clinical importance of hypothyroxinemia in the preterm infant and a discussion of treatment concerns

PURPOSE OF REVIEW

Survival for the extremely low gestational age neonate (ELGAN; 24-28 weeks) has risen to more than 80%. This extraordinary achievement is tempered by the persistence of cognitive delays and cerebral palsy (CP) affecting nearly one in eight survivors, and requiring subsequent rehabilitative services. A major priority in newborn medicine must be to translate the gains in survival achieved over the past 40 years into gains in healthy survival without the current high frequency of impairments.

RECENT FINDINGS

Transient hypothyroxinemia in ELGANs is strongly associated with lower IQ scores, behavioral abnormalities and CP. Limited evidence suggests the possibility of a benefit from hormone replacement therapy, but the optimal trial has yet to be conducted. A continuous infusion of 4 μg/kg per day thyroxine for 42 days can safely correct transient hypothyroxinemia without markedly lowering thyroid stimulating hormone levels, thus creating a biochemical euthyroid state. Whether this treatment will make an impact on long-term outcomes is not yet known.

SUMMARY

With 25 000 neonates born in less than 28 weeks each year in the USA, the economic impact of the very high rates of cognitive disabilities and related neurological dysfunction in survivors is substantial. The lifetime direct and indirect costs of CP are estimated at US$1 million per person and the costs of mental retardation are even higher. If reversal of transient hypothyroxinemia proves effective in reducing the risks of CP or mental retardation in ELGANs by 30%, we estimate an overall saving of US$ 3 billion per year. There is a pressing need for a phase III trial of thyroid hormone that is of sufficient duration and size to determine whether a clinically important reduction in risk of developmental impairments in ELGANs can be achieved.

Vincristine-induced peripheral neuropathy in a neonate with congenital acute lymphoblastic leukemia

We report the case of a 46-day-old boy with a fulminant vincristine-induced peripheral neuropathy after treatment for congenital acute lymphoblastic leukemia. Flaccid paralysis developed at the end of the first phase of induction, requiring intubation and ventilation for 51 days. Treatment was initiated with levocarnitine, N-acetylcysteine, and pyridoxine and progressive reversal of the neuropathy occurred over the next 4 months. Potential differences in pathogenesis and presentation of vincristine neurotoxicity and Guillian-Barre syndrome in the neonate are discussed.

H-reflex and motor nerve conduction studies in growth retarded newborn babies

OBJECTIVE

To demonstrate the accelerated postnatal maturation/myelination in growth retarded babies compensating the deficit suffered by them during intrauterine life.

METHODS

We studied 16 babies within the first 3 days of birth. These included 6 full term appropriate for gestational age babies (FT AGA) and 10 full term intrauterine growth retarded (FT IUGR). A separate group of 16 babies was examined at 2 months of age. In this group 7 were FT AGA and 9 were FT IUGR at the time of birth. H-reflex latency (HRL), motor nerve conduction velocity (MNCV) and H-reflex excitability (H/M) were measured in the right lower limb. Anthropometric measurements of the babies were also recorded meticulously. All the babies were neurologically normal on clinical evaluation.

RESULT

At birth, MNCV was significantly lower in FT IUGR babies compared to FT AGA babies. However at the age of 2 months the MNCV of both FT AGA and FT IUGR was comparable. Other parameters (HRL and H/M) in the IUGR babies were comparable with normal babies both at birth and 2 months of age. In FT IUGR babies crown-heel length and weight was significantly lower than FT AGA babies both at the time of birth and at 2 months of age.

CONCLUSION AND SIGNIFICANCE

The findings suggest that FT IUGR babies demonstrate accelerated postnatal peripheral neural maturation. At 2 months of age, the motor nerve conduction velocity of these growth retarded babies was comparable to that observed in normal AGA babies of similar age. This provides an insight into the functional aspect of the proven theories of decreased peripheral myelination in FT IUGR babies with subsequent rapid postnatal myelination that renders these babies neurologically equivalent to FT AGA babies despite not achieving comparable anthropometric parameters.

Can cortical responses following noxious stimulation inform us about pain processing in neonates?

The measurement of pain in neonates presents a unique challenge. Infants, unable to describe pain verbally, rely on caregivers to assess and manage pain on their behalf. Behavioral and physiological indicators, often used in pain assessment in this population, are assumed surrogate measures of pain processing; however, it has not been proven that these outcome measures correlate with perceived pain, which requires higher cortical processing. Recent studies in neonates have used near-infrared spectroscopy to measure the cortical responses to nociception. The magnitude of these responses can be compared with current clinical pain assessment measures, which provides the opportunity to assess whether these measures are a true reflection of cortical pain processing. This review discusses the use of near-infrared spectroscopy and compares it with alternative pain assessment measures in this vulnerable population.

Somatosensory evoked potentials in very preterm infants

OBJECTIVE

Cross-sectional and longitudinal reference values of cortical N(1) peak latency of the median nerve SEP in very preterm infants.

METHODS

In infants in a placebo control group within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, cortical N(1) peak latency was measured at 2 weeks, at term and at 6 months corrected age. Cross-sectional N(1) latency values obtained in 50 infants and complete series of longitudinal values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA).

RESULTS

Mean N(1) latency decreased from 66 ms at 2 weeks to 38 ms at term and 20 ms at 6 months corrected age. Possible confounding factors did not have any significant effect on N(1) latency at 2 weeks or at term age except cranial ultrasound abnormalities at 2 weeks of age.

CONCLUSIONS

Longitudinal N(1) latency values were consistent with cross-sectional N(1) latency values. The observed N(1) latency at term and at 6 months corrected age suggest that extrauterine maturation of the somatosensory pathway in infants born at less than 30 weeks' gestation is delayed by extrauterine life.