Association between Exposure of Young Children to Procedures Requiring General Anesthesia and Learning and Behavioral Outcomes in a Population-based Birth Cohort. Anesthesiology. 2017;127:227-240. [PMID: 28609302 DOI: 10.1097/aln.0000000000001735]

Astragalin-functionalized ultrasmall nanoparticles modulate the complement pathway to inhibit microglial synaptic phagocytosis for reducing anesthetic neurotoxicity

Synaptic impairment is identified as a primary pathology in sevoflurane-induced neurotoxicity, contributing to neurobehavioral and neurodevelopmental deficits. Synaptic loss in neurons occurs through microglia-mediated synaptic phagocytosis via the complement pathway. Astragalin, a natural flavonoid compound, exhibits diverse bioactivities, such as anti-tumor, anti-complement, and anti-inflammatory effects. Herein, astragalin-functionalized Cu 2-x Se nanoparticles (CSPA NPs) can effectively inhibit the complement pathway, mitigating microglia-mediated synaptic phagocytosis and promoting synaptic restoration to repair sevoflurane-induced neurotoxicity. They efficiently target and reduce microglial activation and phagocytosis. By downregulating sortilin, CSPA NPs increase progranulin expression, promoting TFEB cytoplasmic translocation to decrease lysosomal activity and microglial phagocytosis. Furthermore, CSPA NPs decrease complement C1q and C3 levels, inhibiting microglial synaptic engulfment and ameliorating cognition dysfunction in sevoflurane-treated mice. This study illustrates that CSPA NPs inhibit microglial synaptic elimination via the complement pathway, alleviating sevoflurane-induced neurotoxicity and providing insights into treating complement pathway-related diseases.

Histone lactylation protects against sevoflurane-induced cognitive impairment by regulating YTHDF3/PRDX3 mediated microglial pyroptosis in neonatal mice

BACKGROUND

Sevoflurane (SEV), a widely used inhalational anesthetic, multiple SEV exposures has been implicated in cognitive impairment, particularly in neonates. However, the mechanisms underlying SEV-induced cognitive impairment not fully understood.

METHODS

Neonatal mice or murine microglial line BV-2 cells were exposed to SEV. Morris water maze and novel object recognition tests were used for measuring the cognitive function of mice. Histological examination and immunofluorescence staining were conducted to evaluate hippocampal morphology and the lactylated proteins in microglia, respectively. Cell pyroptosis was measured by flow cytometry and transmission electron microscope, and cytokine levels were detected using ELISA. Protein and gene expression were analyzed through western blot and RT-PCR. The interaction of proteins was verified by CHIP or RIP assays.

RESULTS

SEV induces significant cognitive impairment and reduces both histone lactylation and YTH domain-containing family protein 3 (YTHDF3) expression in the hippocampal tissues of neonatal mice. A decrease in histone lactylation and YTHDF3 expression is accompanied by increased cell pyroptosis and inflammation were observed in SEV-treated BV-2 cells. SEV modulates YTHDF3 expression via histone lactylation, thereby influencing N6-methyladenosine (m6A)-mediated peroxiredoxin 3 (PRDX3) translation and the subsequent activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome mediated pyroptosis in BV-2 cells. Overexpression of YTHDF3 or PRDX3 counteract the SEV-induced promotion of pyroptosis and inflammation in BV-2 cells. Furthermore, histone lactylation enhances YTHDF3 expression and mitigates SEV-induced cognitive dysfunction in neonatal mice, whereas downregulation of YTHDF3 diminishes this protective effect.

CONCLUSION

Our findings elucidate that histone lactylation mitigates SEV-induced cognitive impairment by regulating YTHDF3/PRDX3-mediated microglial pyroptosis in neonatal mice. These insights offer a novel understanding of the molecular mechanisms underlying SEV-induced neurotoxicity in neonates.

Mitophagy impairment drives microglia activation and results in cognitive deficits in neonatal mice following sevoflurane exposure

Sevoflurane exposure induces cognitive deficits in neonatal mice. Mitophagy was closely correlated to sevoflurane inhalation induced neurotoxicity in developing brains. However, the underlying mechanisms have not been fully elucidated. In this study, we attempted to clarify the role of mitophagy in neonatal mice undergoing sevoflurane exposure. BV2 microglial cells were cultured, and mcherry-EGFP-LC3B adenovirus were transfected. The results showed that the fluorescence intensity of GFP was markedly increased after sevoflurane exposure, and rapamycin administration could mitigate this effect. The mitophagy flux test showed that sevoflurane exposure reduced the degree of colocalization between Mito-Traker and Lyso-Traker fluorescent, while which was elevated by rapamycin treatment. The immunofluorescence assay suggested that sevoflurane inhalation resulted in the significant decrease of autolysosome formation, which was sharply enhanced in SEV group after rapamycin treatment. Meanwhile, sevoflurane inhalation shifted microglial M1/M2 phenotypic polarization, and rapamycin administration reversed this status. Moreover, the degree of colocalization among Iba-1, Synaptophysin (Syn) and lysosomal-associated membrane protein 1 (Lamp1) was increased after sevoflurane exposure, and that was reduced following rapamycin treatment. The behavioral performance was worse after sevoflurane inhalation in neonatal mice, and rapamycin treatment effectively improved the cognitive outcome. Collectively, these findings demonstrated that mitophagy impairment induced by sevoflurane exposure promoted microglia M1 phenotypic polarization and enlarged phagocytosis, and resulted in cognitive deficits, while rapamycin administration effectively reversed this tendency.

Diagnostic Techniques for Infantile Subglottic Hemangiomas: A Scoping Review

OBJECTIVE

Infantile subglottic hemangioma (SGH) poses a risk of airway compromise if untreated. Traditionally, operative endoscopy (OH) diagnoses SGH, but since the discovery of beta-blockers' efficacy in treating infantile hemangiomas (IHs) in 2008, and advances in endoscopic technology, nonoperative methods have emerged. This review identifies endoscopic practices for diagnosing and monitoring infantile SGH during the oral beta-blocker treatment era.

DATA SOURCES

A comprehensive literature search in October 2022 and August 2023 covered PubMed, Embase, Cochrane Library, SCOPUS, and Web of Science.

REVIEW METHODS

The search was limited to English-language studies published since 2008, considering this when propranolol was demonstrated as an effective treatment option for IH. The articles were screened for relevance based on predefined inclusion and exclusion criteria.

RESULTS

After inclusion and exclusion criteria, sixty final studies were identified, describing 240 cases of infantile SGH. Most children were diagnosed using OE alone (73.3%; n = 176/240), 23.3% (n = 56/240) using office-based laryngoscopy procedures (OBPs) followed by OE, 3.3% using OBP alone (n = 8/240). There were no reported diagnostic endoscopy-related complications. Twenty-nine studies described using endoscopy plus diagnostic imaging to either confirm an SGH lesion, characterize the extent of disease spread, or rule out other causes of presenting symptoms. The proportion of infants diagnosed with OE alone decreased from 2008 to 2023.

CONCLUSION

Operative endoscopy remains the SGH diagnostic standard, but OBP adoption is increasing. Further research is needed to determine the optimal SGH diagnosis and management approach.

LEVEL OF EVIDENCE

NA Laryngoscope, 135:1287-1294, 2025.

Efficacy of propofol and midazolam combination in managing refractory epileptic encephalopathy with spike-wave activation in sleep

We presented a 7-year-old boy with refractory Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep (EE-SWAS) successfully managed with a combination of propofol and midazolam. His seizures began at age 2, initially controlled by multiple antiseizure medications (ASMs) for almost three years. At age 5, seizures recurred with electroencephalography (EEG) showing electrical status epilepticus in sleep (ESES) and a spike-wave index (SWI) of 85 %. High-dose methylprednisolone pulse therapy initially reduced the SWI to 50 %, but it relapsed to 80 % within six months. Despite further treatments, including methylprednisolone, midazolam infusion, and four combined ASMs, the SWI persisted between 75 % and 85 %, leading to progressively worsening cognitive impairment and subsequently a somnolent state with nearly continuous discharges. During hospitalization, a combination of propofol and midazolam significantly improved the condition, reducing the SWI to 50 % upon completion of the treatment period. Over a three-year follow-up, no ESES or seizures were reported, and cognitive function notably improved. Currently, there is no consensus on the treatment of ESES, which is sometimes refractory to medication and can result in partially irreversible cognitive impairment. Propofol in combination with midazolam has demonstrated effective suppression of ESES phenomena, presenting a promising treatment strategy for refractory ESES.

Regulatory mechanism of LncRNA GAS5 in cognitive dysfunction induced by sevoflurane anesthesia in neonatal rats

BACKGROUND AND OBJECTIVES

Sevoflurane (Sev) exposure may provoke deleterious effects on cognitive function. This study explores the mechanism of long non-coding RNA growth arrest specific transcript 5 (LncRNA GAS5) in Sev-induced cognitive dysfunction in neonatal rats.

METHODS

Cognitive dysfunction was induced by Sev anesthesia in 7-day-old Sprague-Dawley rats, followed by open field test, novel object recognition, radial arm maze, and Morris water maze to evaluate cognitive function of rats. The subcellular localization of LncRNA GAS5 was detected by nucleocytoplasmic isolation assay, and the binding of miR-137 to LncRNA GAS5 and NKCC1 was detected by RNA pull down and dual-luciferase reporter assay, respectively. Adenovirus-packaged sh-LncRNA GAS5 was injected into the hippocampus of Sev rats. qRT-PCR and Western blot were performed to detect the expressions of LncRNA GAS5, miR-137 and NKCC1 in the hippocampus of rats.

RESULTS

Sev anesthesia led to cognitive dysfunction in neonatal rats. LncRNA GAS5 was highly expressed in Sev rats, and inhibition of LncRNA GAS5 alleviated Sev-induced cognitive dysfunction in rats. LncRNA GAS5 targeted miR-137, and miR-137 inhibited NKCC1 expression. Knockdown of miR-137 or overexpression of NKCC1 reversed the effect of LncRNA GAS5 inhibition on cognitive dysfunction in sev rats.

CONCLUSION

LncRNA GAS5 promotes Sev-induced cognitive dysfunction in neonatal rats via the miR-137/NKCC1 axis.

Neurodevelopmental Outcomes after Multiple General Anesthetic Exposures before 5 Years of Age: A Cohort Study

BACKGROUND

The general anaesthesia or awake-regional anaesthesia in infancy (GAS) trial demonstrated evidence that most neurodevelopmental outcomes at 2 and 5 yr of age in infants who received a single general anesthetic for elective inguinal herniorrhaphy were clinically equivalent when compared to infants who did not receive general anesthesia. More than 20% of the children in the trial had at least one subsequent anesthetic exposure after their initial surgery. Using the GAS database, this study aimed to address whether multiple (two or more) general anesthetic exposures compared to one or no general anesthetic exposure in early childhood were associated with worse neurodevelopmental outcomes at 5 yr.

METHODS

Children with multiple general anesthetic exposures and children with one or no general anesthetic exposure were identified from the GAS database. The primary outcome was the full-scale intelligence quotient on the Wechsler Preschool and Primary Scale of Intelligence (third edition) at 5 yr of age. Secondary outcomes included neurocognitive tests addressing all major developmental domains and caregiver-reported questionnaires assessing emotional and behavioral problems.

RESULTS

Complete assessment was available from a total of 90 children in the multiple general anesthetic group and 141 children in the no or one general anesthetic group. Compared with children with a single or no general anesthetic exposure, multiply exposed children scored on average almost 6 points lower (mean, -5.8; 95% CI, -10.2 to -1.4; P = 0.011) in the Wechsler Preschool and Primary Scale of Intelligence full-scale intelligence quotient. They also demonstrated lower verbal and performance IQ scores and more emotional, behavioral, and executive function difficulties. However, significant residual confounding cannot be excluded from the results due to the observational nature of this study.

CONCLUSIONS

Multiple general anesthetic exposures before 5 yr of age were associated with reduced performance in general intelligence score and some domains of neurodevelopmental assessments. The clinical significance of this study's results must be cautiously interpreted in light of several sources of limitations including small sample size and unadjusted residual confounding. This study illustrates the limitations of trial data sets that may not be fit for the purpose for the secondary analysis.

Mechanism of dexmedetomidine in brain injury of infant rats via the IRE1α/NF-κB/CHOP pathway

OBJECTIVE

We investigated the mechanism of Dexmedetomidine (Dex) in infant rats with brain injury.

METHODS

The infant rats underwent brain injury modelling. The motor function, spatial learning and memory abilities in rats, and the hippocampal CA1 region Nissl body level and apoptosis were evaluated by behavioural tests and histological stainings. Levels of the hippocampal CA1 region p-IRE1α, nuclear/cytoplasmic p65, CHOP, Bax and Bcl-2 proteins were determined by Western blot.

RESULTS

Propofol anaesthesia caused brain injury in infant rats. Dex increased the hippocampal CA1 region Nissl body level, abated cell apoptosis, reduced p-IRE1α, ATF6, p-PERK/PERK and CHOP levels, decreased the Bax protein level, elevated the Bcl-2 protein level, and alleviated brain injury in infant rats. After ERS induction and the NF-κB pathway inhibition, the hippocampal CA1 region nuclear/cytoplasmic p65 ratio, CHOP level, and apoptosis were reduced in infant rats with brain injury treated with Dex, while the learning and memory abilities of rats were enhanced.

CONCLUSION

Dex reduced the hippocampal CA1 region cell apoptosis and enhanced learning and memory abilities by inhibiting the ERS-mediated IRE1α/NF-κB/CHOP pathway, thereby alleviating brain injury in infant rats.

A Comparison of Endoscope-Assisted and Open Frontoorbital Distraction for the Treatment of Unicoronal Craniosynostosis

BACKGROUND

Frontoorbital distraction osteogenesis (FODO) is an established surgical technique for patients with unicoronal craniosynostosis. The authors' institution has used an endoscope-assisted technique (endo-FODO) in recent years to decrease cutaneous scarring and lessen the impact on the functional growth matrix. This study compared perioperative outcomes in patients undergoing endo-FODO to those in patients undergoing the traditional coronal approach.

METHODS

Patients with unicoronal craniosynostosis undergoing FODO from 2013 to 2023 were included, and grouped by whether they underwent endo-FODO or a traditional coronal incision. Operative time, estimated blood loss, transfusion volume, and length of hospitalization were compared. Cutaneous scarring at 1 year postoperatively was assessed with the Scar Cosmesis Assessment and Rating (SCAR) scale.

RESULTS

A total of 27 patients (18 traditional and 9 endoscope-assisted) with an average age of 5.6 months (interquartile range [IQR], 5.1 to 6.3 months) at surgery were included, with no difference between groups (P = 0.999). Operative time was 114 minutes (IQR, 92 to 122 minutes) for traditional FODO and 104 minutes (IQR, 95 to 112 minutes) for endo-FODO (P = 0.607). Time under anesthesia was shorter for endo-FODO (traditional, 243 minutes [IQR, 218 to 264 minutes]; endo-FODO, 210 minutes [IQR, 191 to 224 minutes]; P = 0.029). Transfusion volume was 12.2 mL/kg lower for endo-FODO compared with traditional FODO (P = 0.001). Length of stay was similar between groups (P = 0.678). SCAR ratings were 1.83 (IQR, 1.1 to 4.47) in traditional FODO compared with 1.00 (IQR, 0.58 to 1.67) in the endo-FODO (P = 0.036).

CONCLUSIONS

Endo-FODO was associated with reduced time under anesthesia, reduced transfusion requirements, and improved SCAR scores, with no change in duration of surgery, perioperative complications, or length of stay. Future work will compare functional and aesthetic outcomes between techniques.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Unplanned return to the operating room (UPROR) occurs in 40% of MCGR patients at an average of 2 years after initial implantation

PURPOSE

This study calculated the rates of Unplanned Return to the Operating Room (UPROR) in early-onset scoliosis patients who had no previous spine surgery and underwent Magnetically Controlled Growing Rod (MCGR) implantation.

METHODS

We reviewed surgical, radiographic, and UPROR outcomes for EOS patients treated with the MCGR implant < 12 years + 11 months of age, had complete preop/postop major curve measurements, and had complete MCGR details.

RESULTS

376 patients underwent MCGR implantation at a mean age of 7.7 years (1.8-12.9). Diagnoses included 106 (28%) idiopathic, 84 (22%) syndromic, 153 (41%) neuromuscular, and 33 (9%) congenital. The mean preop-cobb was 76.7° (9-145°), and an immediate postop correction was 41% (0-84%). We found that 38% (142/376) of patients experienced an UPROR prior to the maximal actuator length being achieved. UPROR occurred at mean 2 years (3 days-5 years) after initial implantation. Of the 142 patients who experienced UPROR there were 148 complications that lead to an UPROR. The most common reason for UPROR was anchor (55/148: 37%) or MCGR implant related (33/148: 22%). Wound related (22/148:15%), Neuro related 4/148: 3%), and other (34/148: 23%) accounted for the remaining UPROR occurrences.

CONCLUSION

In conclusion, the MCGR UPROR rate was 142/376 (38%) after an average of 2 years post implantation. At 2-year follow-up, only 20% of MCGR patients had experienced an UPROR. However, between 2 and 5 years, the development of an UPROR increased precipitously with only 39% of MCGR patients remaining UPROR free at 5 years post MCGR implantation. The most common reason for UPROR was related to anchor or MCGR implant-related complications. This information can be utilized to set realistic expectations about the need and timing of future surgical procedures with patients and their families.

Early exposure to general anesthesia may contribute to later attention-deficit/hyperactivity disorder (ADHD): A systematic review and meta-analysis of cohort studies

STUDY OBJECTIVE

The association between early childhood exposure to general anesthesia and subsequent risk of developing attention-deficit/hyperactivity disorder remains unknown.

DESIGN

A systematic review and meta-analysis of cohort studies.

PATIENTS

Children undergoing general anesthesia.

INTERVENTIONS

A comparison of any type of general anesthesia exposure, including total intravenous anesthesia, inhalation general anesthesia, and combined intravenous and inhaled anesthesia, with non-anesthetic exposures, which did not receive any exposure to anesthetic drugs, including general anesthetics as well as local anesthetics.

MEASUREMENTS

The primary outcome measure was the risk of developing attention-deficit/hyperactivity disorder after general anesthesia exposure.

MAIN RESULTS

The results of the overall meta-analysis showed an increased risk of subsequent attention-deficit/hyperactivity disorder in children exposed to general anesthesia (RR = 1.26, 95% CI, 1.16-1.38; P < 0.001; I2 = 44.6%). Subgroup analysis found that a single exposure to general anesthesia in childhood was associated with an increased risk of developing attention-deficit/hyperactivity disorder (RR = 1.29, 95% CI, 1.19-1.40, P < 0.001; I2 = 2.6%), and the risk of attention-deficit/hyperactivity disorder was further increased after multiple general anesthesia exposures (RR = 1.61, 95% CI, 1.32-1.97, P < 0.001; I2 = 57.6%). Exposure to general anesthesia lasting 1-60 min during childhood is associated with an increased risk of attention-deficit/hyperactivity disorder (ADHD) (RR: 1.38, 95% CI: 1.26-1.51, P < 0.001; I2 = 0.0%). Moreover, with longer durations of exposure (61-120 min), the risk further rises (RR: 1.55, 95% CI: 1.21-1.99, P = 0.001; I2 = 37.8%). However, no additional increase in ADHD risk was observed with exposures exceeding 120 min (RR: 1.55, 95% CI: 1.35-1.79, P < 0.001; I2 = 0.0%).

CONCLUSIONS

Exposure to general anesthesia during early childhood increases the risk of developing attention-deficit/hyperactivity disorder. In particular, multiple general anesthesia exposures and exposures longer than 60 min significantly increase the risk of developing ADHD.

General Anesthesia Exposure in Infancy and Childhood: A 10-year Bibliometric Analysis

PURPOSE

Heated discussions have divided health care providers and policymakers on the risks versus benefits of general anesthesia in pediatric populations. We conducted this study to provide a comprehensive bibliometric analysis of general anesthesia in this specific population over the past decade.

DESIGN

We summarized and quantitatively analyzed the studies related to general anesthesia in children and infants over the past decade.

METHODS

Using the Web of Science Core Collection as the data source, we analyzed the literature using CiteSpace software, focusing on authors, countries, institutions, keywords, and references to identify hotspots and predict research trends.

FINDINGS

A total of 2,364 publications on pediatric anesthesia were included in the analysis. The number of related publications and citations steadily increased from 2013 to 2022. The United States was the leading country in terms of output, and University of Toronto was the primary contributing institution. Co-citation analysis revealed that over the past decade research has mainly focused on the long-term adverse effects of general anesthesia on neurodevelopment and acute perioperative crisis events. Keyword analysis identified infant sedation and drug selection and compatibility as promising areas for development. In addition, improving the quality of perioperative anesthesia will be a major research focus in the future.

CONCLUSIONS

Recent research in pediatric anesthesia has focused on mitigating the adverse effects of general anesthesia in infants and young children and studying the pharmacological compatibility of anesthetics. Our study results would assist researchers and clinicians in understanding the current research status and optimizing clinical practice in this field.

Autophagic degradation of DHCR7 activates AKT3 and promotes sevoflurane-induced hippocampal neuroinflammation in neonatal mice

Repeated sevoflurane exposure in neonatal mice triggers neuroinflammation with detrimental effects on cognitive function. Yet, the mechanism of the sevoflurane-induced cytokine response is largely unknown. In this study, we reveal that 3-MA, an autophagy inhibitor, attenuated the sevoflurane-induced neuroinflammation and cognitive dysfunction, including the decreased freezing time and fewer platform crossings, in the neonate mice. 3-Methyladenine (3-MA) suppressed sevoflurane-induced expression of interleukin-6 and tumor necrosis factor-alpha in vitro. Moreover, sevoflurane activates IRF3, facilitating cytokine transcription in an AKT3-dependent manner. Mechanistically, sevoflurane-induced autophagic degradation of dehydrocholesterol-reductase-7 (DHCR7) resulted in accumulations of its substrate 7-dehydrocholesterol (7-DHC), mimicking the effect of sevoflurane on AKT3 activation and IRF3-driven cytokine expression. 3-MA significantly reversed sevoflurane-induced DHCR7 degradation, AKT phosphorylation, IRF3 activation, and the accumulation of 7-DHC in the hippocampal CA1 region. These findings pave the way for additional investigations aimed at developing novel strategies to mitigate postoperative cognitive impairment in pediatric patients.

Long-term outcomes of early exposure to repeated general anaesthesia in children with cystic fibrosis (CF-GAIN): a multicentre, open-label, randomised controlled phase 4 trial

BACKGROUND

Long-term effects of early, recurrent human exposure to general anaesthesia remain unknown. The Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) trial provided an opportunity to examine this issue in children randomly assigned in infancy to either repeated bronchoalveolar-lavage (BAL)-directed therapy with general anaesthesia or standard care with no planned lavages up to 5 years of age when all children received BAL-directed therapy under general anaesthesia.

METHODS

This multicentre, randomised, open-label phase 4 trial (CF-GAIN) used the original ACFBAL trial randomisation at 3·6 months (SD 1·6) to BAL-directed therapy or standard-care groups to assess the impact of general anaesthesia exposures over early childhood. Children who completed the ACFBAL trial, with a mean age of 5·1 (SD 0·18) years, received standardised neurobehavioural and health-related-quality-of-life assessment and brain MRI scans between Oct 8, 2013, and June 30, 2017, at a mean age of 12·8 (SD 1·7) years at three hospitals in Australia and one hospital in New Zealand. The primary outcome was a composite score of performance on a standardised, computer-based assessment of child attention, processing speed, and response inhibition skills (Conners Continuous Performance test, second edition). Secondary outcomes included intellectual function, other neurobehavioural measures, and brain imaging as an exploratory outcome. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12613000057785) and is completed.

FINDINGS

At 2 years, the BAL-directed therapy group (n=52) and standard-care group (n=45) had a median of 2·0 (IQR 1·0-3·0) and 0·0 (0·0-0·0) exposures, respectively. At completion of the ACFBAL trial, the BAL-directed therapy group had a median of 6·0 (4·0-9·5) exposures and the standard-care group 2·0 (1·0-4·0) exposures. At CF-GAIN completion, the BAL-directed therapy group had a median of 10·0 (IQR 6·5-14·5) exposures and the standard-care group 4·0 (3·0-7·0) exposures. Cumulative general anaesthesia exposure time was not prospectively collected but, for those with complete cumulative exposure time data to the end of the ACFBAL trial, the median cumulative exposure time for the BAL-directed therapy group (n=29) was 180 (IQR 140-285) min and for the standard-care group (n=32) was 48 (30-122) min. The mean Conners Continuous Performance test, second edition composite score was 51 (SD 8·1) in BAL-directed therapy group and 53 (8·8) in the standard-care group; difference -1·7 (95% CI -5·2 to 1·7; p=0·32) with similar performance on other neurobehavioural measures, including measures of executive function, intellectual quotient scores, and brain imaging.

INTERPRETATION

Our findings suggest that repeated general anaesthesia exposure in young children with cystic fibrosis is not related to functional impairment in attention, intellectual quotient, executive function, or brain structure compared with a group with fewer and shorter cumulative anaesthesia durations.

FUNDING

National Health and Medical Research Council Australia, Queensland Government Health Service and Clinical Innovation Fellowship, and the Children's Hospital Foundation Queensland.

Damage-associated molecular patterns as a mechanism of sevoflurane-induced neuroinflammation in neonatal rodents

BACKGROUND

General anesthesia is inevitable for pediatric patients undergoing surgery, though volatile anesthetic agents may cause neuroinflammation and neurodevelopmental impairment; however, the underlying pathophysiology remains unclear. We aimed to investigate the neuroinflammation mechanism in developing rat brains associated with sevoflurane exposure time, by identifying the specific damage-associated molecular patterns (DAMPs) pathway and evaluating the effects of non-steroidal anti-inflammatory drugs (NSAIDs) in alleviating neuroinflammation.

METHODS

A three-step experiment was conducted to investigate neuroinflammation induced by sevoflurane. First, the exposure time required for sevoflurane to cause neuroinflammation was determined. Next, the specific pathways of DAMPs involved in neuroinflammation by sevoflurane were identified. Finally, the effects of NSAIDs on sevoflurane-induced neuroinflammation were investigated. The expression of various molecules in the rat brain were assessed using immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction, western blot analysis, and enzyme-linked immunosorbent assay.

RESULTS

In total, 112 rats (aged 7 days) were used, of which six rats expired during the experiment (mortality rate, 5.3%). Expression of CD68, HMGB-1, galectin-3, TLR4, TLR9, and phosphorylated NF-κB was significantly increased upon 6 h of sevoflurane exposure. Conversely, transcriptional levels of TNF-α and IL-6 significantly increased and IFN-γ significantly decreased after 6 h of sevoflurane exposure. Co-administration of NSAIDs with sevoflurane anesthesia significantly attenuated TNF-α and IL-6 levels and restored IFN-γ levels.

CONCLUSIONS

In conclusion, 6 h of sevoflurane exposure induces neuroinflammation through the DAMPs pathway, HMGB-1, and galectin-3. Co-administration of ibuprofen reduced sevoflurane-induced neuroinflammation.

Modulating neuroinflammation and cognitive function in postoperative cognitive dysfunction via CCR5-GPCRs-Ras-MAPK pathway targeting with microglial EVs

AIMS

Postoperative cognitive dysfunction (POCD) is prevalent among the elderly, characterized primarily by cognitive decline after surgery. This study aims to explore how extracellular vesicles (EVs) derived from BV2 microglial cells, with and without the C-C chemokine receptor type 5 (CCR5), affect neuroinflammation, neuronal integrity, and cognitive function in a POCD mouse model.

METHODS

We collected EVs from LPS-stimulated BV2 cells expressing CCR5 (EVsM1) and from BV2 cells with CCR5 knockdown (EVsM1-CCR5). These were administered to POCD-induced mice. Protein interactions between CCR5, G-protein-coupled receptors (GPCRs), and Ras were analyzed using structure-based docking and co-immunoprecipitation (Co-IP). We assessed the phosphorylation of p38 and Erk, the expression of synaptic proteins PSD95 and MAP2, and conducted Morris Water Maze tests to evaluate cognitive function.

RESULTS

Structure-based docking and Co-IP confirmed interactions between CCR5, GPR, and Ras, suggesting a CCR5-GPCRs-Ras-MAPK pathway involvement in neuroinflammation. EVsM1 heightened neuroinflammation, reduced synaptic integrity, and impaired cognitive function in POCD mice. In contrast, EVsM1-CCR5 reduced neuroinflammatory markers, preserved synaptic proteins, enhanced dendritic spine structure, and improved cognitive outcomes.

CONCLUSION

EVsM1 induced neuroinflammation via the CCR5-GPCRs-Ras-MAPK pathway, with EVsM1-CCR5 showing protective effects on POCD progression, suggesting a new therapeutic strategy for POCD management via targeted modification of microglial EVs.

GABA system as the cause and effect in early development

GABA is the primary inhibitory neurotransmitter in the adult brain and through its actions on GABAARs, it protects against excitotoxicity and seizure activity, ensures temporal fidelity of neurotransmission, and regulates concerted rhythmic activity of neuronal populations. In the developing brain, the development of GABAergic neurons precedes that of glutamatergic neurons and the GABA system serves as a guide and framework for the development of other brain systems. Despite this early start, the maturation of the GABA system also continues well into the early postnatal period. In this review, we organize evidence around two scenarios based on the essential and protracted nature of GABA system development: 1) disruptions in the development of the GABA system can lead to large scale disruptions in other developmental processes (i.e., GABA as the cause), 2) protracted maturation of this system makes it vulnerable to the effects of developmental insults (i.e., GABA as the effect). While ample evidence supports the importance of GABA/GABAAR system in both scenarios, large gaps in existing knowledge prevent strong mechanistic conclusions.

General anesthetic agents induce neurotoxicity through oligodendrocytes in the developing brain

General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells. Oligodendrocytes perform essential roles in the central nervous system, including myelin sheath formation, axonal metabolism, and neuroplasticity regulation. They are particularly vulnerable to the effects of general anesthetic agents resulting in impaired proliferation, differentiation, and apoptosis. Neurologists are increasingly interested in the effects of general anesthetic agents on oligodendrocytes. These agents not only act on the surface receptors of oligodendrocytes to elicit neuroinflammation through modulation of signaling pathways, but also disrupt metabolic processes and alter the expression of genes involved in oligodendrocyte development and function. In this review, we summarize the effects of general anesthetic agents on oligodendrocytes. We anticipate that future research will continue to explore these effects and develop strategies to decrease the incidence of adverse reactions associated with the use of general anesthetic agents.

Translatome and transcriptome profiling of neonatal mice hippocampus exposed to sevoflurane anesthesia

Exposure to anesthesia in early life may cause severe damage to the brain and lead to cognitive impairment. The underlying mechanisms, which have only been investigated in a limited scale, remains largely elusive. We performed translatome and transcriptome sequencing together for the first time in hippocampus of neonatal mice that were exposed to sevoflurane. We treated a group of neonatal mice with 2.5 % sevoflurane for 2 h on day 6, 7, 8, 9 and treated another group on day 6, 7. We performed behavioral study after day 30 for both groups and the control to evaluate the cognitive impairment. On day 36, we collected translatome and transcriptome from the hippocampus in the two groups, compared the gene expression levels between the groups and the control, and validated the results with RT-qPCR. We identified 1750 differentially expressed genes (DEGs) from translatome comparison and 1109 DEGs from transcriptome comparison. As expected, translatome-based DEGs significantly overlapped with transcriptome-based DEGs, and functional enrichment analysis generated similar enriched cognition-related GO terms and KEGG pathways. However, for many genes like Hspa5, their alterations in translatome differed remarkably from those in transcriptome, and Western blot results were largely concordant with the former, suggesting that translational regulation plays a significant role in cellular response to sevoflurane. Our study revealed global alterations in translatome and transcriptome of mice hippocampus after neonatal exposure to sevoflurane anesthesia and highlighted the importance of translatome analysis in understanding the mechanisms responsible for anesthesia-induced cognitive impairment.

Epigenetic Mechanism of SETD1B-mediated Histone Methylation in Cognitive Impairment Induced by Sevoflurane Anesthesia in Neonatal Mice

Sevoflurane (Sev) anesthesia is associated with cognitive deficits and neurotoxicity. This study explores the epigenetic mechanism of SET domain containing 1B (SETD1B) in Sev-induced cognitive impairment in neonatal mice. Neonatal mice (C57BL/6, n = 72) were exposed to 3% Sev for 2 h per day at P6, 7, and 8, and the control neonatal mice were only separated from the mother for 2 h. The mice were divided into groups of 12 individuals, with an equal number of male and female mice in each group. Mice were intraperitoneally injected with adenovirus-packaged SETD1B overexpression vector. Behavioral tests (Morris water maze, open field test, T-maze, novel object recognition, etc.) were performed at P30. Mouse hippocampal neuronal cells were cultured in vitro. SETD1B, C-X-C motif chemokine receptor 4 (CXCR4), NLR family pyrin domain containing 1 (NLRP1), Cleaved Caspase1, and GSDMD-N expressions in hippocampal tissues or cells were determined by quantitative real-time polymerase chain reaction and Western blot. SETD1B and histone H3 lysine 4 methylation (H3K4me1, H3K4me2, and H3K4me3) enrichment on the CXCR4 promoter was analyzed by ChIP. Sev insulted cognitive impairment and diminished SETD1B expression in mouse hippocampal tissues. SETD1B overexpression mitigated cognitive impairment, enhanced H3K4me3 levels in hippocampal tissues, and restrained hippocampal neuronal pyroptosis. SETD1B increased CXCR4 expression by elevating the H3K4me3 level on the CXCR4 promoter, thereby curbing NLRP1/Caspase1-mediated hippocampal neuronal pyroptosis. To conclude, SETD1B enhances CXCR4 expression by elevating the H3K4me3 level on the CXCR4 promoter, thereby suppressing NLRP1/Caspase1-triggered hippocampal neuronal pyroptosis and alleviating Sev-induced cognitive impairment in neonatal mice.

Institutional Variability in Anesthesia Time for Mehta Casting in Early-Onset Scoliosis (EOS)

PURPOSE

Mehta casting is a potentially curative intervention for early-onset scoliosis (EOS) that typically requires multiple anesthetics. The Food and Drug Administration (FDA) reported that >3 hours of anesthesia under the age of 3 years old may alter brain development; however, no standard exists for the duration of anesthesia during casting. The purpose of this study is to quantify the variability in anesthesia during Mehta casting. We hypothesize that significant institutional variability exists and may be attributed to modifiable factors.

METHODS

An EOS registry was used to identify patients who underwent at least one Mehta casting procedure. Anesthesia exposure was quantified, and site variability was assessed by patient characteristics, cast placement, procedure type, and equipment used.

RESULTS

Our cohort consisted of 208 patients from 5 institutions (age 2.6±1.4 y). There were 1097 Mehta casting procedures, with 5.4±3.6 castings per patient. Of these patients, 106 (51%) were female, with an average age of 2.11±1.29 years old at the time casting was initiated. Patient etiologies included 154 idiopathic (74.0%), 22 syndromic (10.6%), 18 congenital (8.7%), 11 neuromuscular (5.3%), and 3 unknown (1.4%). Anesthesia time was 69±31 minutes and varied significantly between sites (59±14 to 117±46 min; P <0.001). Cumulative anesthesia time for patients under 3 years was 320±197 minutes with 120/161 (74.5%) patients exceeding 3 hours. Anesthesia time was lower after the FDA warning in 2016 compared with pre-2016 (71±30 vs. 66±32, P =0.008).

CONCLUSIONS

Patients undergoing Mehta casting are at significant risk of exceeding 3 hours of anesthesia, which the FDA has stated may be harmful for children <3 years. Significant site variability indicates that standardization protocols should be developed to encourage best practices and minimize anesthetic times.

LEVEL OF EVIDENCE

Prognostic Level II.

Diagnostic and therapeutic strategies in early onset scoliosis: A current concept review

Substantial advances in the treatment of early onset scoliosis (EOS) over the past two to three decades have resulted in significant improvements in health-related quality of life of affected children. In addition to classifications that address the marked heterogeneity of this patient population, increasing understanding of the natural history of the disease, and new implants and treatment techniques have resulted in innovations unlike any other area of pediatric orthopedics. The growing understanding of the interaction between spinal and thoracic growth, as well as dependent lung maturation, has had a lasting impact on the treatment strategy of this potentially life-threatening disease. The previous treatment approach with early corrective fusion gave way to a growth-friendly concept. Despite the steady development of new growth-friendly surgical treatment options, whose efficacy still needs to be validated, as well as a revival of conservative growth control with serial casts and/or braces, the psychosocial burden of the long lasting and complication-prone treatments remains high. As a consequence, EOS still represents one of the greatest pediatric orthopedic challenges.

Global Trends and Hotspots in Pediatric Anesthetic Neurotoxicity Research: A Bibliometric Analysis From 2000 to 2023

The impact of general anesthetics on brain function development is one of the top frontier issues of public concern. However, little bibliometric analysis has investigated this territory systematically. Our study aimed to visualize the publications between 2000 and 2023 to inspire the trends and hotspots in anesthetic neurodevelopmental toxicity research. Publications from 2000 to 2023 were collected from the Web of Science Core Collection. CiteSpace was utilized to plot and analyze the network maps of countries, institutions, authors, journals, and keywords associated with these publications. A total of 864 publications, consisting of 786 original articles and 78 reviews, were extracted from 2000 to 2023. The annual publications have increased constantly over the past two decades. The USA and the People's Republic of China were the leading driving forces in this field. Harvard University was the most productive institution. Zhang Y published the most related articles, and Jevtovic-Todorovic V was mostly cited in this field. The most prolific journal was Pediatric Anesthesia, and the most frequently co-cited journal was Anesthesiology. Keywords were divided into nine clusters: "apoptosis", "propofol", "developing brain", "cognitive dysfunction", "neuronal cell degeneration", "brain", "neuroinflammation", "local anesthesia", and "oxygen therapy". The strongest citation bursts in earlier years were "learning disability", "cell death", and "cognitive function". The emerging trends in the coming years were "awake regional anesthesia", "behavioral outcome", and "infancy general anesthesia compared to spinal anesthesia". We conclude that anesthetic-induced neurotoxicity has received growing attention in the past two decades. Our findings evaluated the present status and research trends in this area, which may provide help for exploring further potential prospects on hot topics and frontiers.

A New Approach for Diagnosis and Surveillance of Infantile Subglottic Hemangioma in the Era of Propranolol Use: A Case Series

OBJECTIVE

To report our institutional experience in diagnosing and surveilling patients with infantile subglottic hemangioma (SGH) using in-office flexible fiberoptic laryngoscopy (FFL) with video technology, without requiring operative endoscopy in the era of propranolol use.

METHODS

A retrospective case series was conducted on 4 children diagnosed with SGH between 2016 and 2022 at our institution.

RESULTS

Awake FFL with video technology provided adequate visualization of SGH lesions for diagnosis, without any complications. Serial examinations of the airway were performed in the outpatient setting and each SGH gradually regressed, with marked improvement in respiratory symptoms within 48 hours of oral propranolol initiation.

CONCLUSION

Our findings showed that in select patients, FFL with video technology can successfully identify SGH lesions without general anesthesia exposure. FFL may be used as a low-risk screening tool for propranolol therapy initiation in some patients, but operative endoscopy should remain the gold standard procedure for others. By utilizing FFL in this manner, it is possible to diagnose SGH lesions and start propranolol therapy without exposing all patients to the risks of operative endoscopy.

Risk of attention deficit hyperactivity disorder diagnosis following multiple exposures to general anesthesia in the paediatric population: A systematic review and meta-analysis

Objectives

The risk of attention deficit hyperactivity disorder (ADHD) following multiple exposures to anesthesia has been debated. Our objective was to systematically review the literature to examine the association between multiple exposures to general anesthesia before age 5 and subsequent diagnosis of ADHD.

Methods

A systematic search of EMBASE, PubMed, and SCOPUS was performed using key search terms in February 2022. We included studies that: were published after 1980, included only otherwise healthy children who experienced two or more exposures to general anesthetic before age 5, diagnosed ADHD by a medical professional before age 19 years after exposure to general anesthetic, were cross-sectional, case-control, or cohort study, and were published in English. The results (expressed as hazard ratios [HR] and associated 95% confidence intervals [CI]) were pooled using meta-analytic techniques. Studies which did not present their results as HR and 95% CI were analyzed separately. GRADE was used to determine the certainty of the findings. PRISMA guidelines were followed at each stage of the review.

Results

Eight studies (196,749 children) were included. Five reported HR and 95% CI and were subsequently pooled for meta-analysis. Multiple exposures to anesthesia were associated with diagnosis of ADHD before the 19th year of life (HR: 1.71; 95% CI: 1.59, 1.84). Two of the three studies not used in the meta-analysis also found an increased risk of ADHD diagnosis following multiple anesthetic exposures.

Conclusions

There was an association between multiple early exposures to general anesthesia and later diagnosis of ADHD.

Needle in a haystack: localising the long-term neuronal changes from early-life exposure to general anaesthesia

Narrowing down the histopathological changes in the brain after early-life exposure to general anaesthesia has presented a consistent challenge for preclinical models of anaesthetic neurotoxicity. Using resting-state functional magnetic resonance imaging, in this issue of the journal Neudecker and colleagues demonstrated in vivo connectivity changes in the brain following a seed-based analysis that was derived from previously reported histopathology in the same animals. The combination of neurohistology and neuroimaging should help focus future preclinical studies investigating the developmental consequences of early exposure to general anaesthesia.

M1-Type Microglia-Derived Extracellular Vesicles Overexpressing IL-1R1 Promote Postoperative Cognitive Dysfunction by Regulating Neuronal Inflammation

Postoperative cognitive dysfunction (POCD) is a common complication after surgical anesthesia, mainly manifested as memory impairment, decreased attention, and cognitive function with mood and personality changes. Activated microglia (M1-type microglia) have been demonstrated to release inflammatory substances (IL-1β, TNF-α, etc.) that cause neuronal degeneration and death by activating the NF-κB signaling pathway and upregulating Caspase-3 and Bax. However, the pathogenesis of POCD is still not fully understood and needs further research. In the present study, we investigated the effect of M1-type microglia-derived extracellular vesicles (EVsM1-Microglia) in the pathological process of POCD. The levels of NF-κB phosphorylation and IL-1β protein expression in hippocampal neurons were significantly increased in the Surgery group, while PSD95 and MAP2 were significantly decreased. Surgery induced microglia activation, synapse-associated protein decrease, and neuronal degeneration in hippocampus. And the amount of spine and mushroom spine significantly decreased in surgical mice, which was reverted in the presence of IL-1R1 siRNA. In addition, EVsM1-Microglia promoted synaptic loss and neuron degeneration independent of surgery and microglia activation. Furthermore, EVsM1-Microglia promoted memory defects in surgical mice. We demonstrated that EVsM1-Microglia with high expression of IL-1R1 promote POCD development by regulating neuronal inflammation.

The Role of Neuroactive Steroids in Analgesia and Anesthesia: An Interesting Comeback?

Published evidence over the past few decades suggests that general anesthetics could be neurotoxins especially when administered at the extremes of age. The reported pathology is not only at the morphological level when examined in very young and aged brains, given that, importantly, newly developing evidence suggests a variety of behavioral impairments. Since anesthesia is unavoidable in certain clinical settings, we should consider the development of new anesthetics. A promising and safe solution could be a new family of anesthetics referred to as neuroactive steroids. In this review, we summarize the currently available evidence regarding their anesthetic and analgesic properties.

Differential epitranscriptome and proteome modulation in the brain of neonatal mice exposed to isoflurane or sevoflurane

BACKGROUND

Repeated neonatal exposure to anesthetics may disturb neurodevelopment and cause neuropsychological disorders. The m6A modification participates in the gene regulation of neurodevelopment in mouse fetuses exposed to anesthetics. This study aims to explore the underlying molecular mechanisms of neurotoxicity after early-life anesthesia exposure.

METHODS

Mice were exposed to isoflurane (1.5%) or sevoflurane (2.3%) for 2 h daily during postnatal days (PND) 7-9. Sociability, spatial working memory, and anxiety-like behavior were assessed on PND 30-35. Synaptogenesis, epitranscriptome m6A, and the proteome of brain regions were evaluated on PND 21.

RESULTS

Both isoflurane and sevoflurane produced abnormal social behaviors at the juvenile age, with different sociality patterns in each group. Synaptogenesis in the hippocampal area CA3 was increased in the sevoflurane-exposed mice. Both anesthetics led to numerous persistent m6A-induced alterations in the brain, associated with critical metabolic, developmental, and immune functions. The proteins altered by isoflurane exposure were mainly associated with epilepsy, ataxia, and brain development. As for sevoflurane, the altered proteins were involved in social behavior.

CONCLUSIONS

Social interaction, the modulation patterns of the m6A modification, and protein expression were altered in an isoflurane or sevoflurane-specific way. Possible molecular pathways involved in brain impairment were revealed, as well as the mechanism underlying behavioral deficits following repeated exposure to anesthetics in newborns.

Behavioral and Cognitive Outcomes of Rhesus Macaques Following Neonatal Exposure to Antiseizure Medications

OBJECTIVE

Exposure of neonatal macaques to the antiseizure medications phenobarbital and midazolam (PbM) causes widespread apoptotic death of neurons and oligodendrocytes. We studied behavior and neurocognitive performance in 12 to 24 month-old macaques treated as neonates with PbM.

METHODS

A total of 14 monkeys received phenobarbital and midazolam over 24 hours under normothermia (n = 8) or mild hypothermia (n = 6). Controls (n = 8) received no treatment. Animals underwent testing in the human intruder paradigm at ages 12 and 18 months, and a 3-step stimulus discrimination task at ages 12, 18, and 24 months.

RESULTS

Animals treated with PbM displayed lower scores for environmental exploration, and higher scores for locomotion and vocalizations compared with controls. Combined PbM and hypothermia resulted in lower scores for aggression and vigilance at 12 months compared with controls and normothermic PbM animals. A mixed-effects generalized linear model was used to test for differences in neurocognitive performance between the control and PbM groups in the first step of the stimulus discrimination task battery (shape center baited to shape center non-baited). The odds of passing this step differed by group (p = 0.044). At any given age, the odds of passing for a control animal were 9.53-fold (95% CI 1.06-85) the odds for a PbM animal. There was also evidence suggesting a higher learning rate in the shape center non-baited for the control relative to the PbM group (Cox model HR 2.13, 95% CI 1.02-4.43; p = 0.044).

INTERPRETATION

These findings demonstrate that a 24-hour-long neonatal treatment with a clinically relevant combination of antiseizure medications can have long-lasting effects on behavior and cognition in nonhuman primates. ANN NEUROL 2023.

Neurodevelopmental outcomes in individuals with VACTERL association. A population-based cohort study

BACKGROUND

Studies on neurodevelopmental outcomes in individuals with congenital anomalies who undergo neonatal surgery are scarce and have reported contradictory findings based on small study groups. The congenital condition VACTERL association includes at least three malformations: vertebral anomalies, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal anomalies and limb deformities. Most of these patients undergo surgery during their first days of life. Neurodevelopmental disorders include a broad group of disabilities involving some form of disruption to brain development. Attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASD) and intellectual disability (ID) are diagnoses included in this group. The aim of the study was to investigate the risk of ADHD, ASD and ID in a cohort of individuals with VACTERL association.

METHOD

Data was obtained from four Swedish national health registers and analyzed using the Cox proportional hazards model. Patients born 1973-2018 in Sweden with the diagnosis of VACTERL association were included in the study. For each case five healthy controls matched for sex, gestational age at birth, birth year and birth county were obtained.

RESULTS

The study included 136 individuals with VACTERL association and 680 controls. Individuals with VACTERL had significantly higher risk of ADHD, ASD and ID than the controls; 2.25 (95% CI, 1.03-4.91), 5.15 (95% CI, 1.93-13.72) and 8.13 (95% CI, 2.66-24.87) times respectively.

CONCLUSIONS

A higher risk of ADHD, ASD and ID was found among individuals with VACTERL association compared to controls. These results are of importance to caregivers and to professionals participating in follow ups of these patients in providing early diagnosis and support, aiming to optimize the quality of life of these patients.

MicroRNAs-Based Theranostics against Anesthetic-Induced Neurotoxicity

Various clinical reports indicate prolonged exposure to general anesthetic-induced neurotoxicity (in vitro and in vivo). Behavior changes (memory and cognition) are compilations commonly cited with general anesthetics. The ability of miRNAs to modulate gene expression, thereby selectively altering cellular functions, remains one of the emerging techniques in the recent decade. Importantly, engineered miRNAs (which are of the two categories, i.e., agomir and antagomir) to an extent found to mitigate neurotoxicity. Utilizing pre-designed synthetic miRNA oligos would be an ideal analeptic approach for intervention based on indicative parameters. This review demonstrates engineered miRNA's potential as prophylactics and/or therapeutics minimizing the general anesthetics-induced neurotoxicity. Furthermore, we share our thoughts regarding the current challenges and feasibility of using miRNAs as therapeutic agents to counteract the adverse neurological effects. Moreover, we discuss the scientific status and updates on the novel neuro-miRNAs related to therapy against neurotoxicity induced by amyloid beta (Aβ) and Parkinson's disease (PD).

Anesthesia, the developing brain, and dexmedetomidine for neuroprotection

Anesthesia-induced neurotoxicity is a set of unfavorable adverse effects on central or peripheral nervous systems associated with administration of anesthesia. Several animal model studies from the early 2000's, from rodents to non-human primates, have shown that general anesthetics cause neuroapoptosis and impairment in neurodevelopment. It has been difficult to translate this evidence to clinical practice. However, some studies suggest lasting behavioral effects in humans due to early anesthesia exposure. Dexmedetomidine is a sedative and analgesic with agonist activities on the alpha-2 (ɑ₂) adrenoceptors as well as imidazoline type 2 (I2) receptors, allowing it to affect intracellular signaling and modulate cellular processes. In addition to being easily delivered, distributed, and eliminated from the body, dexmedetomidine stands out for its ability to offer neuroprotection against apoptosis, ischemia, and inflammation while preserving neuroplasticity, as demonstrated through many animal studies. This property puts dexmedetomidine in the unique position as an anesthetic that may circumvent the neurotoxicity potentially associated with anesthesia.

Early exposure to general anaesthesia and increasing trends in developmental behavioural impairments: is there a link?

Over the past two decades there has been an increase in reports of attention deficit-hyperactivity disorder and perhaps autism spectrum disorder that appear to coincide with a substantial number of general anaesthesia interventions during early stages of human brain development. Is there a link between anaesthesia exposure and neurocognitive effects considering the growing body of evidence in numerous animal species, including humans, that suggests long-lasting socio-affective behavioural impairments after early exposure to general anaesthesia? Could routinely used general anaesthetics contribute as environmental toxins? Here we present the case that this notion is worthy of further consideration.

Associations between maternal exposure to surgery or pregnancy exposure to fluorinated anesthetics and children's cognitive development and educational outcomes

A transgenerational, epigenetic effect of anesthesia, particularly fluorinated agents, has been examined in rat models, but translation to humans is unclear. This study examined associations of maternal lifetime exposure to anesthesia and pregnancy exposure to fluorinated anesthetics with child cognitive and educational outcomes. Women in the US Collaborative Perinatal Project (1959-1963) reported lifetime history of surgeries, and the obstetric record captured pregnancy exposure to anesthetics. Children were followed to age 7 for global cognitive ability and educational outcomes (n=47,977). Logistic and linear regressions were adjusted for maternal and child birth years, race and ethnicity, smoking, education, parity, study site. Many outcomes were not associated with exposure to maternal surgery that occurred at various life stages. However, maternal surgery in early childhood was associated both with being in a special school or not in school (adj OR=1.42; 95% CI 1.02, 1.98) and with slightly better cognitive ability across childhood (e.g., WISC IQ (adj β=0.59; CI 0.13, 1.04) (especially among boys)). Maternal surgery in puberty was associated with slightly lower IQ (adj β = -0.42; CI -0.79, -0.05) and poorer spelling at age 7. Children's prenatal exposure to fluorinated anesthetics was associated with slightly better spelling ability (adj β = 1.20; CI 0.02, 2.38) but lower performance IQ at age 7 (only among boys, adj β = -1.97; CI -3.88, -0.06). This study shows inconsistent evidence of effects of maternal exposure to surgery or prenatal exposure to fluorinated agents on child developmental and educational outcomes Residual confounding by indication and socioeconomic status may explain observed associations.

Neonatal sevoflurane exposure induces long-term changes in dendritic morphology in juvenile rats and mice

General anesthetics are potent neurotoxins when given during early development, causing apoptotic deletion of substantial number of neurons and persistent neurocognitive and behavioral deficits in animals and humans. The period of intense synaptogenesis coincides with the peak of susceptibility to deleterious effects of anesthetics, a phenomenon particularly pronounced in vulnerable brain regions such as subiculum. With steadily accumulating evidence confirming that clinical doses and durations of anesthetics may permanently alter the physiological trajectory of brain development, we set out to investigate the long-term consequences on dendritic morphology of subicular pyramidal neurons and expression on genes regulating the complex neural processes such as neuronal connectivity, learning, and memory. Using a well-established model of anesthetic neurotoxicity in rats and mice neonatally exposed to sevoflurane, a volatile general anesthetic commonly used in pediatric anesthesia, we report that a single 6 h of continuous anesthesia administered at postnatal day (PND) 7 resulted in lasting dysregulation in subicular mRNA levels of cAMP responsive element modulator (Crem), cAMP responsive element-binding protein 1 (Creb1), and Protein phosphatase 3 catalytic subunit alpha, a subunit of calcineurin (Ppp3ca) (calcineurin) when examined during juvenile period at PND28. Given the critical role of these genes in synaptic development and neuronal plasticity, we deployed a set of histological measurements to investigate the implications of anesthesia-induced dysregulation of gene expression on morphology and complexity of surviving subicular pyramidal neurons. Our results indicate that neonatal exposure to sevoflurane induced lasting rearrangement of subicular dendrites, resulting in higher orders of complexity and increased branching with no significant effects on the soma of pyramidal neurons. Correspondingly, changes in dendritic complexity were paralleled by the increased spine density on apical dendrites, further highlighting the scope of anesthesia-induced dysregulation of synaptic development. We conclude that neonatal sevoflurane induced persistent genetic and morphological dysregulation in juvenile rodents, which could indicate heightened susceptibility toward cognitive and behavioral disorders we are beginning to recognize as sequelae of early-in-life anesthesia.

Multiple exposures to sevoflurane across postnatal development may cause cognitive deficits in older age

BACKGROUND

The aim of the study was to determine the effects of repeated anesthesia exposure across postnatal development.

METHODS

Seventy-two newborn Sprague-Dawley rats were randomly divided into Sev group and Con-aged group. Sev groups were exposed to 2.6% sevoflurane for 2 h on postnatal day (P) 7, P14, and P21; the Con groups only received carrier gas for 2 h. Learning and memory were evaluated using the MWM test at P31 (juvenile), P91 (adult), and 18 months postnatally (aged). The relative expression of APP and Mapt mRNA was detected by RT-PCR, while Aβ, tau, and P-tau protein levels were analyzed by immunohistochemistry.

RESULTS

After repeated inhalation of sevoflurane, MWM test performance was significantly decreased in the Sev-aged group compared to the Con-aged group (P > 0.05). The relative expression of APP and Mapt mRNA was not significantly different between groups in each growth period (P > 0.05). The tau expression in the juvenile hippocampal CA1, CA3, and dentate gyrus regions increased markedly in the Sev group, while P-tau only increased in the hippocampal CA3 region in the Sev-adult group. The expression of tau, P-tau, and Aβ in the hippocampal regions was upregulated in the Sev-aged group.

CONCLUSIONS

Multiple exposures to sevoflurane across postnatal development can induce or aggravate cognitive impairment in old age.

IMPACT

Whether multiple sevoflurane exposures across postnatal development cause cognitive impairment in childhood, adulthood, or old age, as well as the relationship between sevoflurane and the hippocampal Aβ, tau, and P-tau proteins, remains unknown. This study's results demonstrate that multiple exposures to sevoflurane across postnatal development do not appear to affect cognitive function in childhood and adulthood; however, multiple exposures may lead to a cognitive function deficit in old age. The underlying mechanism may involve overexpression of the tau, P-tau, and Aβ proteins in the hippocampus.

Association Between Receipt of General Anesthesia During Childhood and Attention Deficit Hyperactive Disorder and Neurodevelopment

BACKGROUND

There are inconsistent reports regarding the association between general anesthesia and adverse neurodevelopmental and behavioral disorders in children.

METHODS

This nationwide administrative cohort study included children born in Korea between 2008 and 2009, and followed until December 31, 2017. The cohort included 93,717 participants who received general anesthesia with endotracheal intubation (ETI) who were matched to unexposed subjects in a 1:1 ratio. General anesthesia was defined by National Health Insurance Service treatment codes with intratracheal anesthesia, and the index date was the first event of general anesthesia. The primary outcome was attention deficit hyperactive disorder (ADHD), which was defined as at least a principal diagnosis of 10th revision of the International Classification of Diseases code F90.X after the age of 72 months. Neurodevelopment, which was assessed using a developmental screening test (Korean-Ages and Stages Questionnaire [K-ASQ]), was a secondary outcome. The K-ASQ is performed annually from 1 to 6 years of age and consists of 5 domains. The association between general anesthesia and ADHD was estimated using a Cox hazard model, and its association with neurodevelopment was estimated using a generalized estimation equation, with control for multiple risk factors beyond 1 year after the index date.

RESULTS

The median age at the index date was 3.8 (95% confidence interval [CI], 1.7-5.8) years, and there were 57,625 (61.5%) men. During a mean follow-up period of 5 years, the incidence rate of ADHD was 42.6 and 27.7 per 10,000 person-years (PY) in the exposed and unexposed groups, respectively (absolute rate difference 14.9 [95% CI, 12.5-17.3] per 10,000 PY). Compared to the unexposed group, the exposed group had an increased risk of ADHD (adjusted hazard ratio, 1.41 [95% CI, 1.30-1.52]). In addition, a longer duration of anesthesia with ETI and more general anesthesia procedures with ETI were associated with greater risk of ADHD. General anesthesia with ETI was also associated with poorer results in the K-ASQ.

CONCLUSION

Administration of general anesthesia with ETI to children is associated with an increased risk of ADHD and poor results in a neurodevelopmental screening test.

Repeated early-life exposure to anaesthesia and surgery causes subsequent anxiety-like behaviour and gut microbiota dysbiosis in juvenile rats

BACKGROUND

Early exposure to general anaesthetics for multiple surgeries or procedures might negatively affect brain development. Recent studies indicate the importance of microbiota in the development of stress-related behaviours. We determined whether repeated anaesthesia and surgery in early life cause gut microbiota dysbiosis and anxiety-like behaviours in rats.

METHODS

Sprague Dawley rats received skin incisions under sevoflurane 2.3 vol% three times during the first week of life. After 4 weeks, gut microbiota, anxiety-related behaviours, hippocampal serotonergic activity, and plasma stress hormones were tested. Subsequently, we explored the effect of faecal microbiota transplantation from multiple anaesthesia/surgery exposed rats after administration of a cocktail of antibiotics on anxiety-related behaviours.

RESULTS

Anxiety-like behaviours were observed in rats with repeated anaesthesia/surgery exposures: In the OF test, multiple anaesthesia/surgery exposures induced a decrease in the time spent in the centre compared to the Control group (P<0.05, t=3.05, df=16, Cohen's d=1.44, effect size=0.58). In the EPM test, rats in Multiple AS group travelled less (P<0.05, t=5.09, df=16, Cohen's d=2.40, effective size=0.77) and spent less time (P<0.05, t=3.58, df=16, Cohen's d=1.69, effect size=0.65) in the open arms when compared to the Control group. Repeated exposure caused severe gut microbiota dysbiosis, with exaggerated stress response (P<0.01, t=4.048, df=16, Cohen's d=-1.91, effect size=-0.69), a significant increase in the hippocampal concentration of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) (P<0.05; for 5-HT: t=3.33, df=18, Cohen's d=-1.49, effect size=-0.60; for 5-HIAA: t=3.12, df=18, Cohen's d=-1.40, effect size=-0.57), and changes in gene expression of serotonergic receptors later in life (for Htr1a: P<0.001, t=4.49, df=16, Cohen's d=2.24, effect size=0.75; for Htr2c: P<0.01, t=3.72, df=16, Cohen's d=1.86, effect size=0.68; for Htr6: P<0.001, t=7.76, df=16, Cohen's d=3.88, effect size=0.89). Faecal microbiota transplantation led to similar anxiety-like behaviours and changes in the levels of 5-hydroxytryptamine and 5-hydroxyindoleacetic acid.

CONCLUSIONS

Gut microbiota dysbiosis caused by early repeated exposure to anaesthesia and surgery affects long-term anxiety emotion behaviours in rats.

A Comprehensive Assessment of Psychosocial Well-being Among Growing Rod Graduates: A Preliminary Investigation

BACKGROUND

Traditional growing rods (TGR) encompass a long process, in which patients experience physical and psychosocial difficulties. However, the effect of repeating surgeries on the overall psychological functioning of graduated patients has not been thoroughly investigated in the literature. The aim of this study is to evaluate the psychological well-being of graduated idiopathic early-onset scoliosis patients in terms of psychopathology, neurocognition, and psychosocial functioning, and determine the accuracy of scoliosis outcome questionnaires in these regards.

METHODS

TGR graduates with idiopathic early-onset scoliosis without known intellectual disabilities or neuromuscular impairments were included. Patients were thoroughly evaluated using psychological instruments [Wechsler Adult Intelligence Scale, Auditory Consonant Trigram Test, Verbal Fluency Test, Beck Depression Inventory, Beck Anxiety Inventory, Rosenberg Self-Esteem Scale, Symptom Checklist-90, Post-Traumatic Growth Inventory, Strengths and Difficulties Questionnaire, Spinal Appearance Questionnaire, Scoliosis Research Society 22-item questionnaire (SRS-22)]. Results were compared with normative data when available. Spearman correlations were performed between the results of these tests, the total treatment duration, and the number of spinal surgeries.

RESULTS

Of the 15 patients included in the study, 9 were females, and the mean age was 18.73 (16 to 23). The mean age at index surgery was 6.38 (3 to 10) whereas that of graduation was 14.00 (12 to 16). The average number of spinal surgeries was 14.28 (7 to 20). Two patients performed below the range of adult intellectual functioning. Auditory Consonant Trigram Test showed normal verbal working memory and attention control. Six patients had abnormal Verbal Fluency Test performance. Eight patients had abnormal ratings on at least one of the assessment scales of psychopathology (Symptom Checklist-90, Beck Depression Inventory, and Beck Anxiety Inventory). Eight patients had low-to-moderate self-esteem (Rosenberg self-esteem scale). The median spinal appearance questionnaire and SRS-22 scores were 34 and 4.18, respectively. Pain and function subdomains of SRS-22 scored higher than self-image and mental health. No correlation was found between the treatment duration and number of surgeries and test scores. SRS-22 showed correlations with multiple psychological tests.

CONCLUSION

Completed TGR treatment yields acceptable correction of deformities and surgical outcomes, however, may fail to improve psychological well-being. This is the first study to find various psychosocial abnormalities in two-thirds of cases.

LEVEL OF EVIDENCE

Level IV; cross-sectional study.

Risk of Neurotoxicity with Multiple General Anaesthetics for Examination Under Anaesthesia in Paediatric Ophthalmology - A Cause for Concern?

Purpose

To evaluate the impact of clinical protocol change via active minimisation on the number of general anaesthetic (GA)/sedation episodes for diagnostic ophthalmic purposes at Children's Health Ireland at Temple Street (CHI-TS), Dublin, Ireland, from 2016 to 2019, inclusive. Change was implemented following published cautionary principles in 2016 by the FDA regarding the potential neurotoxic risk from multiple GA exposure in children.

Methods

Retrospective analysis of electronic operating theatre records was completed using procedure codes "Ophthalmological examination" and "Examination of fundi". Available records for patients undergoing multiple examination under anaesthesia (EUA) procedures were assessed for demographics, indication. Comparison was made regarding overall EUA numbers and breakdown for each year, before and after the new departmental approach. From 2018 onward, a patient-centred, departmental strategy of active minimisation of EUA was adopted, using strategies of "training, technology and patience". A literature review was conducted using online databases.

Results

A total of 450 EUAs were performed over the 4 years investigated. In the former 2 years of the study period, prior to departmental policy change, EUAs represented 32% (304 of 948 total theatre episodes) of the ophthalmic theatre caseload. In the latter 2 years of this study period, this proportion fell to 19% (146 EUAs of 783 theatre episodes). Total theatre case numbers were comparable in both time periods. Eighteen children had multiple EUAs (ie, ≥2 EUAs, mean 6.5, SD 2.9) for life/sight threatening indications, totalling 116 EUAs (25.7%).

Conclusion

A significant reduction in diagnostic EUA volume was accomplished resulting in reduced individual patient risk and increased capacity for surgical interventions. A detailed description of this methodology is included for the purposes of replication at comparable units. EUA will continue to play a crucial role in the management of life/sight threatening conditions but the application of a cautionary principle to reduce EUA, where possible, is appropriate to reduce potential for neurotoxicity.

Parvalbumin interneuron loss mediates repeated anesthesia-induced memory deficits in mice

Repeated or prolonged, but not short-term, general anesthesia during the early postnatal period causes long-lasting impairments in memory formation in various species. The mechanisms underlying long-lasting impairment in cognitive function are poorly understood. Here, we show that repeated general anesthesia in postnatal mice induces preferential apoptosis and subsequent loss of parvalbumin-positive inhibitory interneurons in the hippocampus. Each parvalbumin interneuron controls the activity of multiple pyramidal excitatory neurons, thereby regulating neuronal circuits and memory consolidation. Preventing the loss of parvalbumin neurons by deleting a proapoptotic protein, mitochondrial anchored protein ligase (MAPL), selectively in parvalbumin neurons rescued anesthesia-induced deficits in pyramidal cell inhibition and hippocampus-dependent long-term memory. Conversely, partial depletion of parvalbumin neurons in neonates was sufficient to engender long-lasting memory impairment. Thus, loss of parvalbumin interneurons in postnatal mice following repeated general anesthesia critically contributes to memory deficits in adulthood.

Spatial and temporal alterations of developing oligodendrocytes induced by repeated sevoflurane exposure in neonatal mice

The general anesthesia associated with long-term cognitive impairment has been causing the concern of the whole society. In particular, repeated anesthetic exposures may affect executive function, processing speed, and fine motor skills, which all directly depended on the functions of oligodendrocytes, myelin, and axons. However, the underlying mechanisms are still largely unknown. To investigate the spatial and temporal alterations in oligodendrocytes in the corpus callosum (CC) and hippocampus following repeated sevoflurane exposures (3%, for 2 h) from postnatal day 6 (P6) to P8, we used immunofluorescence, Western blot, and a battery of behavioral tests. As previously stated, we confirmed that early anesthetic exposures hampered both cognitive and motor performance during puberty in the rotarod and banes tests. Intriguingly, we discovered that the proliferation of oligodendrocyte progenitor cells (OPCs) was immediately enhanced after general anesthesia in the CC and hippocampus from P8 to P32. From P8 through P15, the overall oligodendrocyte population remained constant. However, along with the structural myelin abnormalities, the matured oligodendrocytes statistically reduced in the CC (from P15) and hippocampus (from P32). Administration of clemastine, which could induce OPC differentiation and myelin formation, significantly increased matured oligodendrocytes and promoted myelination and cognition. Collectively, we first demonstrated the bi-directional influence of early sevoflurane exposures on oligodendrocyte maturation and proliferation, which contributes to the cognitive impairment induced by general anesthesia. These findings illustrated the dynamic changes in oligodendrocytes in the developing brain following anesthetic exposures, as well as possible therapeutic strategies for multiple general anesthesia associated cognitive impairment.

The evolving stall rate of magnetically controlled growing rods beyond 2 years follow-up

PURPOSE

Magnetically controlled growing rods (MCGR) have become the dominant distraction-based implant for the treatment of early onset scoliosis (EOS). Recent studies, however, have demonstrated rising rates of implant failure beyond short-term follow-up. We sought to evaluate a single-center experience with MCGR for the treatment of EOS to define the rate of MCGR failure to lengthen, termed implant stall, over time.

METHODS

A single-center, retrospective review was conducted identifying children with EOS undergoing primary MCGR implantation. The primary endpoint was the occurrence of implant stalling, defined as a failure of the MCGR to lengthen on three consecutive attempted lengthening sessions with minimum of 2 years follow-up. Clinical and radiographic variables were collected and compared between lengthening and stalled MCGRs. A Kaplan-Meier survival analysis was conducted to assess implant stalling over time.

RESULTS

A total of 48 children met inclusion criteria (mean age 6.3 ± 1.8 years, 64.6% female). After a mean 56.9 months (range of 27 to 90 months) follow-up, 25 (48%) of children experienced implant stalling at a mean of 26.0 ± 14.1 months post-implantation. Kaplan-Meier survival analysis demonstrated that only 50% of MCGR continue to successfully lengthen at 2 years post-implantation, decreasing to < 20% at 4 years post-implantation.

CONCLUSION

Only 50% of MCGR continue to successfully lengthen 2 years post-implantation, dropping dramatically to < 20% at 4 years, adding to the available knowledge regarding the long-term viability and cost-effectiveness of MCGR in the management of EOS. Further research is needed to validate these findings.

Impact of Anesthetic Exposures on the Neurocognitive Profiles of Pediatric Brain Tumor Survivors: A New Direction for Research and Multidisciplinary Collaboration

Primary brain tumors are the most commonly diagnosed solid tumors in children, and pediatric brain tumor survivors experience lasting, pervasive deficits of neurocognitive functioning. Repeated exposure to anesthetic drugs is a necessary component not only of surgical resection but also of multimodal cancer care for the youngest patients with brain tumors. The potential for anesthetic neurotoxicity to worsen neurocognitive outcomes in this vulnerable group, therefore, warrants our attention and further study through multi-disciplinary collaboration. This review discusses neurocognitive functioning in pediatric brain tumor survivors, highlighting the findings of a recent study of children with tumors of the posterior fossa which identified treatment-related risk factors for neurocognitive difficulties, with those undergoing multimodal therapies (eg, chemotherapy and irradiation) experiencing the greatest deficits compared with healthy controls. The role of anesthetic neurotoxicity in long-term outcomes among pediatric brain tumor survivors is also reviewed.

A bibliometric analysis of the neurotoxicity of anesthesia in the developing brain from 2002 to 2021

Background

The neurotoxicity effects of anesthetic exposure on the developing brain have been one of the current research hotspots and numerous articles were published in the past decades. However, the quality and comparative information of these articles have not been reported. This research aimed to provide a comprehensive overview of the current state of the field by investigating research hotspots and publication trends concerning the neurotoxicity of anesthesia in the developing brain.

Materials and methods

On 15 June 2022, we searched articles on the neurotoxicity of anesthesia in the developing brain through the Science Citation Index databases from 2002 to 2021. Data of the author, title, publication, funding agency, date of publication, abstract, type of literature, country, journal, keywords, number of citations, and research direction were collected for further analysis.

Results

We searched and analyzed 414 articles in English on the field of neurotoxicity of anesthesia in the developing brain from 2002 to 2021. The country with the largest number of publications was The United States (US) (n = 226), which also had the largest total number of citations (10,419). Research in this field reached a small peak in 2017. Furthermore, the largest number of articles were published in three journals, Anesthesiology, Anesthesia and Analgesia, and Pediatric Anesthesia. The top 20 articles that were cited most often were studied. In addition, the top hotspots of this area in clinical investigations and basic research were analyzed separately.

Conclusion

This study provided an overview of the development in the neurotoxicity of anesthesia in the developing brain using bibliometric analysis. Current clinical studies in this area were mainly retrospective; in the future, we should place more emphasis on prospective, multicenter, long-term monitoring clinical studies. More basic research was also needed on the mechanisms of neurotoxicity of anesthesia in the developing brain.

Classification of Skull Shape Deformities Related to Craniosynostosis on 3D Photogrammetry

Implementation of the Utrecht Cranial Shape Quantificator (UCSQ) classification method on 3D photogrammetry in patients with different types of craniosynostosis is the aim of the present study. Five children (age <1 year) of every group of the common craniosynostoses (scaphocephaly, brachycephaly, trigonocephaly, right-sided and left-sided anterior plagiocephaly) were randomly included. The program 3-Matic (v13.0) was used to import and analyze the included 3dMD photos. Three external landmarks were placed. Using the landmarks, a base plane was created, as well as a plane 4 cm superior to the base plane. Using UCSQ, we created sinusoid curves of the patients, the resulting curves were analyzed and values were extracted for calculations. Results per patient were run through a diagnostic flowchart in order to determine correctness of the flowchart when using 3D photogrammetry. Each of the patients (n=25) of the different craniosynostosis subgroups is diagnosed correctly based on the different steps in the flowchart. This study proposes and implements a diagnostic approach of craniosynostosis based on 3D photogrammetry. By using a diagnostic flowchart based on specific characteristics for every type of craniosynostosis related to specific skull deformities, diagnosis can be established. All variables are expressed in number and are therefore objective.