Many cases of SIDS may be caused by a defect in the structure of the hippocampus, the area of the brain responsible for e.g. for regulating the work of the heart, breathing, maintaining the correct body temperature and memory. The information was published by Acta Neuropathologica.
Scientists from Boston Children’s Hospital and Harvard Medical School (USA) examined the brains of 153 children who died of sudden infant death between 1991 and 2012. In 86 cases the cause of death was unknown. The others had a diagnosed cause (including infection or hypoxia). In the case of 41 percent. children from the group with an unidentified cause of death, a defect was detected in the area of the dentate gyrus included in the hippocamapa formation (the anomaly consisted in the presence of an additional, unnecessary layer of nerve cells).
According to the researchers, this abnormality could destabilize functions such as regulating breathing and heart rate during sleep and brief wakes at night. A similar defect in the structure of the hippocampus was previously observed in people suffering from temporal epilepsy. It is therefore also possible that the baby’s breathing stops as a result of a nocturnal episode of epilepsy. Another possibility is disturbances in the metabolism of serotonin. However, more research is needed to verify these hypotheses.
The nature of the lesions with the dentate gyrus suggests that the disturbance in its development occurred at some point in fetal life or the first months after birth. We saw no signs of hypoxia brain damage, says study author Dr Hannah C. Kinney, adding that SIDS can have many causes, but identifying each one helps identify the risk group. (PAP)