Human Studies of Anesthesia-Related Neurotoxicity in Children: A Narrative Review of Recent Additions to the Clinical Literature

Experiencing anesthesia and surgery early in life impairs cognitive and behavioral development

Background

The impact of anesthesia and surgery on neurocognitive and behavioral development in infants and children remains inadequately understood.

Objective

To investigate the impact of early-life exposure to general anesthesia and surgery on cognitive and behavioral development.

Methods and materials

Children aged 0-3 years who underwent general anesthesia and surgical procedures between 2012 and 2015 were included. The cognitive and behavioral development of these children at ages 4-6 years was assessed. Age-, race-, and gender-matched children from the same geographic region, who did not undergo general anesthesia or surgery, served as the control group. The Wechsler Preschool Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) was used to evaluate children's total intelligence quotient (FSIQ) and specific cognitive domains. The Gesell Development Schedules (GSCH) and Child Behavior Checklist (CBCL) were employed to assess behavioral and personality development. Additionally, the study analyzed the effects of various factors including anesthesia drugs, surgery duration, number of surgeries, age, weight, ethnicity, and gender on postoperative neurocognitive and behavioral outcomes.

Results

The study included 447 children with anesthesia/surgical exposure (AS) and 459 children in the control group. Analysis of cognitive and behavioral development showed a significant difference in the working memory index (WMI) between the AS and control groups (p < 0.05). Exploratory findings indicated that children administered remifentanil exhibited lower developmental quotient (DQ) values, whereas those given fentanyl showed higher (worse) Child Behavior Checklist (CBCL) total scores. Moreover, increased anesthesia/surgical exposures, younger age and lower body weight at exposure, and longer surgery durations were associated with cognitive and behavioral developmental challenges.

Conclusion

This study examined the impact of early-life exposure to surgery and anesthesia on postoperative cognitive and behavioral development. Findings indicate that higher frequency of exposure to surgery and anesthesia, younger age, and lower body weight at exposure could negatively influence cognitive and behavioral development. Furthermore, variations in the effects of different anesthetics on behavior and cognition were observed. Caution is advised regarding the use of opioid analgesics such as remifentanil and fentanyl for more rigorous clinical applications.

Knowledge, Attitude, and Performance of Pregnant Women Regarding General Anesthesia Neurotoxicity in Children under Three: A Report from an Academic Hospital

Background: Recently, concerns about general anesthesia (GA)-related neurotoxicity has been growing in societies. Parents’ information obviously plays an important role to make right decision for elective surgeries on children aged under three years old. Objectives: The aim of this survey was to evaluate the knowledge, attitude, and performance of pregnant women about the GA-related neurotoxicity in children aged under three years old. Methods: This descriptive study was conducted at Alzahra Teaching Hospital in Guilan, Iran, during 2020. The eligible pregnant women admitted to this center were interviewed, and a questionnaire containing 10 items was filled out by the responsible resident of anesthesiology. Results: In this research, a total of 361 pregnant women were enrolled and underwent a face-to-face interview. The mean age of the participants was 31.4 ± 7 years, 64.5% were living in urban areas, 82.5% were housewives, and 65.7% were multipara. Moreover, 83.7% of participants believed that receiving information in this regard was crucial, and 81.7% preferred physicians as the source of information. Only 8% of mothers had received information regarding the issue. A significant correlation was observed between the habitat, employment, the level of education, knowledge, and attitude status, and the source of receiving information. Conclusions: According to our results, the knowledge, attitude, and performance of pregnant women were not optimal and needed to be improved through practical strategies.

MRI Protocol for Pituitary Assessment in Children with Growth or Puberty Disorders-Is Gadolinium Contrast Administration Actually Needed?

The aim of this study was to assess the diagnostic value of non-contrast pituitary MRI in children with growth or puberty disorders (GPDs) and to determine the criteria indicating the necessity to perform post-contrast examination. A retrospective study included re-analysis of 567 contrast-enhanced pituitary MRIs of children treated in a tertiary reference center. Two sets of sequences were created from each MRI examination: Set 1, including common sequences without contrast administration, and Set 2, which included common pre- and post-contrast sequences (conventional MRI examination). The differences in the visibility of pituitary lesions between pairs of sets were statistically analyzed. The overall frequency of Rathke’s cleft cysts was 11.6%, ectopic posterior pituitary 3.5%, and microadenomas 0.9%. Lesions visible without contrast administration accounted for 85% of cases. Lesions not visible before and diagnosed only after contrast injection accounted for only 0.18% of all patients. Statistical analysis showed the advantage of the antero-posterior (AP) pituitary dimension over the other criteria in determining the appropriateness of using contrast in pituitary MRIs. The AP dimension was the most significant factor in logistic regression analysis: OR = 2.23, 95% CI, 1.35–3.71, p-value = 0.002, and in ROC analysis: AUC: 72.9% with a cut-off value of 7.5 mm, with sensitivity/specificity rates of 69.2%/73.5%. In most cases, the use of gadolinium-based contrast agent (GBCA) in pituitary MRI in children with GPD is unnecessary. The advantages of GBCA omission include shortening the time of MRI examination and of general anesthesia; saving time for other examinations, thus increasing the availability of MRI for waiting children; and acceleration in their further clinical management.

Neuroimaging for the Primary Care Provider: A Review of Modalities, Indications, and Pitfalls

When evaluating a child with a potential neurologic or neurodevelopmental disorder, identifying indications for imaging and the correct imaging modality to order can be challenging. This article provides an overview of computed tomography, MRI, ultrasonography, and radiography with an emphasis on indications for use, pitfalls to be avoided, and recent advances. A discussion of the appropriate use of ionizing radiation, intravenous contrast, and sedation is also provided.

Long Noncoding RNA SPRY4-IT1 Modulates Ketamine-Induced Neurotoxicity in Human Embryonic Stem Cell-Derived Neurons through EZH2

OBJECTIVE

This study aimed to investigate whether long noncoding RNA sprouty receptor tyrosine kinase signaling antagonist 4-intronic transcript 1 (SPRY4-IT1) is involved in the regulation of ketamine-induced neurotoxicity.

METHODS

Human embryonic stem cells (hESCs) were induced into neurons in vitro and treated with ketamine. Apoptosis and neurite degeneration assays were used to determine ketamine-induced neurotoxicity and qRT-PCR to determine SPRY4-IT1 expression. SPRY4-IT1 was downregulated in hESC-induced neurons to examine its regulation on ketamine-induced neurotoxicity. The correlation between enhancer of zeste homolog 2 (EZH2) and SPRY4-IT1 was also examined. EZH2 was upregulated in SPRY4-IT1-downregualted hESC-induced neurons to further examine its participation in SPRY4-IT1-mediated ketamine neurotoxicity.

RESULTS

Ketamine-induced dose-dependent apoptosis, neurite degeneration, and SPRY4-IT1 upregulation in hESC-induced neurons. Lentivirus-mediated SPRY4-IT1 downregulation protected ketamine neurotoxicity. EZH2 expression was positively correlated with SPRY4-IT1 in hESC-induced neurons. EZH2 overexpression markedly reversed the protective effects of SPRY4-IT1 knockdown on ketamine neurotoxicity.

CONCLUSIONS

SPRY4-IT1 is involved in anesthesia-induced neurotoxicity, possibly through the regulation on EZH2 gene.

Essential Infantile Esotropia: A Course of Treatment From Our Experience

Background: Essential infantile esotropia (EIE) is the most common type of childhood esotropia. Although its classical approach is surgical, less invasive techniques have been proposed as an adjunct or alternative to traditional surgery. Among them, chemodenervation with botulinum toxin (BT) has been investigated, showing variable and sometimes conflicting results. Objectives: To compare the outcomes of bilateral BT injection and traditional surgery in a pediatric population with EIE in order to optimize and standardize the therapeutic approach. Other purposes are to evaluate whether early intervention may prevent the onset of vertical ocular deviation (which is part of the clinical picture of EIE) and/or influence the development of fine stereopsis, and also to assess changes in refractive status over time among the enrolled population. Methods: A retrospective consecutive cohort study was conducted in 86 children aged 0-48 months who underwent correction of EIE. The primary intervention in naïve subjects was either bilateral BT injection (36 subjects, "BT group") or strabismus surgery (50 subjects, "surgery group"). Results: Overall, BT chemodenervation (one or two injections) was effective in 13 (36.1%) subjects. With regard to residual deviation angle, the outcomes at least 5 years after the last intervention were overlapping in children receiving initial treatment with either injection or surgery; however, the success rate of primary intervention in the surgery group was higher, and the average number of interventions necessary to achieve orthotropia was smaller. Both early treatment with chemodenervation and surgery at a later age were not found to prevent the onset of vertical ocular deviation, whereas, surprisingly, the percentage of subjects developing fine stereopsis was higher in the surgery group. Finally, with regard to the change in refractive status over time, most of the subjects increased their initial hyperopia, whereas 10% became myopic. Conclusions: Our data suggest that a single bilateral BT injection by age 2 years should be considered as the first-line treatment of EIE without vertical component; whereas, traditional surgery should be considered as the first-line treatment for all other cases and in subjects unresponsive to primary single BT injection.

Minimally-Invasive Surgical Approach to Congenital Dacryostenosis: Proposal for a New Protocol

Background: Congenital dacryostenosis is one of the most common ophthalmological disorders in infants, with a high spontaneous resolution rate. In patients unresponsive to conservative treatment, the first-line approach is lacrimal drainage system probing, thought there is no clear consensus on optimal timing of surgery. The optimal treatment of patients unresponsive to primary probing is also controversial. Objectives: The aim of this study is to assess the optimal timing of probing in children with congenital dacryostenosis. Other purposes are to evaluate the efficacy of repeated probing and dacryointubation in patients unresponsive to the initial surgery without evident lacrimal outflow dysgenesis, and to determine the epidemiology of these maldevelopments. Methods: A retrospective consecutive cohort study was conducted in 625 eyes of 457 patients aged 7-48 months who underwent surgery for dacryostenosis. Patients were divided into 4 cohorts according to the timing of surgery. Data were analyzed using Fisher's test. Results: The success rate of primary probing was high, without significant differences between cohorts. One-third of recurrences were related to maldevelopments, the other two-thirds were treated with a second probing or dacryointubation, with high success rates, that did not significantly differ between the procedures. All cases unresponsive to the second surgery were resolved with dacryointubation. Conclusions: Probing is highly effective and its outcome is not affected by timing of surgery. Nevertheless, we advocate for early intervention, in order to identify possible maldevelopments, which require more invasive management. In patients unresponsive to primary probing, without evident maldevelopments, repeated probing should still be considered as the first-line approach, since it's less invasive but similarly effective to dacryointubation.