Brainstem Abnormalities Linked to Sudden Infant Death

Rebecca Lewis November 19, 2013

Researchers at Boston Children’s Hospital in the US found that babies, who die suddenly and unexpectedly both in safe and unsafe sleep conditions, have underlying brainstem abnormalities and are not all normal prior to death.

Such abnormalities impair brainstem circuits that control breathing, heart rate, blood pressure and temperature during sleep. The researchers believe that these prevent babies from rousing when they re-breath too much carbon dioxide (due to inadequate ventilation) or become overheated (from overbundling).

Sudden infant death syndrome (SIDS), also known as cot death, refers to the unexpected and unexplained death of apparently healthy baby. In the UK, at least 300 babies die suddenly and unexpectedly every year, according to the NHS. Even experts are clueless about the real cause of SIDS but it is thought to be a result of a combination of factors. Epidemiologic studies suggest that infants dying unexpectedly are often found in unsafe sleep environments, such as sleeping face down with their face in the pillow, or sleeping with another person in the bed.

In the current study, the researchers reviewed the data of 71 infants who had SIDS and had their brainstem samples taken for analysis. The infants were grouped according to sleep circumstances—those considered safe (asphyxia not likely) or unsafe (asphyxia likely) based upon death-scene investigation reports. The results were compared with 9 infants who died from other known causes (controls).

Findings revealed an association between brainstem neurochemical abnormalities and SIDS. Groups A and B showed abnormalities in the serotonin, serotonin receptors, GABA receptors and 14-3-3 (a protein that regulates serotonin). Whilst the neurochemical measures didn’t differ significantly between the two groups, each group differed significantly from the control group.

According to the research team, headed by Hannah Kinney, MD, a neuropathologist at Boston Children’s, their findings confirm that sudden unexplained death in infants is associated with underlying vulnerabilities, and that not all infants who die in compromised sleep environments are normal. "Certainly, there are unsafe sleeping environments that can cause any baby to die, such as entrapment in the crib, but if it’s just sleeping face down, the baby who dies may have an underlying brainstem vulnerability," she said.

"We have to find ways to test for this underlying vulnerability in living babies and then to treat it. Our team is focused now upon developing such a test and treatment.” Dr Kinney added that sleep practices are absolutely important so the infants are not put in unsafe conditions that can cause sudden, unexpected death.

Their work was published in the journal Paediatrics.

Source of this article:

Whether sleep environment is safe or not, SIDS is linked to brainstem abnormality