Purpose of review: Due to increased frequency of surgical interventions, infants and young children are exposed to anesthesia, often repeatedly, during an extremely delicate period of brain development. We review new evidence that continues to challenge the safety of this practice.
Recent findings: In animal models, anesthesia impairs normal synapse development and sculpting, which are crucial elements of developmental synaptogenesis. This age-dependent phenomenon is caused in part by actin cytoskeleton disorganization and impaired dendritic branching. Recent evidence also suggests that developing glia are sensitive to anesthesia-induced toxicity, which is manifested as stunted growth, delayed maturation, and disturbed process formation. Newly published findings in nonhuman primates, which report long-lasting cognitive impairment, stress the potential seriousness of anesthesia-induced developmental neurotoxicity.
Summary: Although clinical importance remains to be substantiated, results to date do indicate that exposure of animals to general anesthesia during active synaptogenesis is most detrimental. Accordingly, it is essential to determine when synaptogenesis begins and ends in developing humans. It is also imperative that effective preventive techniques be developed so that existing anesthetics can be used with minimum risk of neurotoxic side-effects of anesthesia.