The Journal of Pediatrics (Pediatrics) recently reported a case of a seven-month-old female infant who died suddenly in her sleep, with a preliminary diagnosis of sudden infant death syndrome (SIDS) after an unexplained cause of death on autopsy, clinical history review, and death scene investigation. Subsequently, neuropathological examination of the brainstem revealed significant damage to the last region of the medulla oblongata, which may have been caused by repeated heavy use of indoor pesticides in the weeks prior to death. The infant girl was seven months old and died suddenly and unexpectedly during sleep. A complete autopsy did not reveal any significant disease features, including meningitis, sepsis, pneumonia, and myocarditis. Other causes of death, such as dehydration, electrolyte imbalance, congenital disorders, genetic metabolic abnormalities, and carbon monoxide poisoning, were also ruled out one by one. No useful diagnostic information was found in the history review and death scene investigation, and SIDS was tentatively identified. Histopathological sections of the brainstem revealed significant damage to the most posterior region at the base of the fourth ventricle. As shown in Figure A, the caudal coronal section of the medulla oblongata showed significant laceration-like damage to the posteriormost region with marked neuronal apoptosis in the eroded region; Figure B shows a histological section of the posteriormost region in a normal child of the same age. This histological manifestation cannot be explained by organogenesis imperfecta, suggesting that the damage to the final region of the medulla oblongata may have been directly caused by toxic substances. Mass spectrometry techniques were used to identify fresh tissue samples from the cerebral cortex for possible toxicological analysis (e.g., secondhand smoke, drugs, alcohol, air pollution, and pesticides). Most of the mass spectral peaks were found to be fatty acids and endogenous matrix components, with one mass spectral peak associated with the presence of 2,6-tert-butyl-4-nitrophenol (DBNP), a toxic contaminant that kills mites and is the active ingredient in indoor pesticides. Investigators learned even further through her parents that a large amount of insecticide had been sprayed around the infant two weeks earlier due to indoor fly infestation. This finding provided a reliable explanation for the suddenness of the infant girl’s death and enabled a differential diagnosis with SIDS, the leading cause of death of children in the late neonatal period in developed countries, usually defined as a sudden and unexpected death of an infant or child up to one year of age for which the cause remains undetermined by autopsy, history review, and assessment of the circumstances of death. Since most of this fatal event occurs during sleep, the presumed probable cause is impaired maturation of the infant’s whistling center. The vascularized last region of the medulla oblongata is a small nodule located at the base of the fourth ventricle, in the dorsal midline of the medulla oblongata, and is typical of the periventricular apparatus. This structure is the most vascularized region of the human brain, but lacks a blood-brain barrier, and thus blood-borne substances can reach the brain parenchyma directly via here. It also contains a large number of catecholaminergic neurons that selectively transmit molecules from the blood and brain crest fluid and prevent the diffusion of harmful substances. The neurons in the posteriormost region of the medulla have long been considered as emetic reflex receptors in response to noxious chemical stimuli. Recently, it has been shown that neurons in the posteriormost region also receive afferent signals from sensory neurons in the gastrointestinal, liver, kidney, heart and other visceral organs, and also send the collected information to important brainstem centers. In this case, the overabsorption of insecticide may have caused severe damage to the last region of the medulla oblongata, resulting in impaired recognition of harmful substances, inability to prevent their direct entry into the brainstem, and compromised central regulatory functions, which led to the unexpected death of the infant. Since this report is only a single case, it does not conclude that the overuse of indoor pesticides is directly related to brain damage, but it provides a direction for further in-depth research. The public is also alerted to the risk of misuse of toxic chemical contaminants.