(Br J Anaesth. 2018;120:546–554)
The “brain growth spurt” (BGS) during fetal development is a vulnerable period characterized by synaptogenesis, dendritic arborization, extensive myelination, and chemical changes. Exposure to ionizing radiation (IR) may have detrimental effects on this period of development. In experimental rodent models, a single neonatal IR dose of 0 to 100 mGy during the BGS period induced modification in behavior of the mice, with a proposed developmental neurotoxicity at 350 mGy, and alteration in cerebral cortex tau levels at 500 mGy. In addition, rodent neonatal exposure to ketamine has been shown to cause acute apoptotic neurodegeneration, alterations of essential neuroproteins, induction of hyperactive phenotype, and cognitive impairment. As pediatric patients often undergo radiotherapy or sedation/anesthesia before or during radiologic procedures, the authors of the present study explored whether IR doses in the range of exposure associated with computerized tomography (CT) scans could interact with low doses of ketamine to induce neurotoxicity in the developing mouse brain.