New brainstem research adds to understanding of SIDS 

1 November 2006

A summary of the research findings of David Paterson et al on multiple serotonergic brainstem abnormalities in Sudden Infant Death Syndrome (SIDS)

On 1 November 2006, new research findings were published in the Journal of the American Medical Association that shed new light on a possible vulnerability to SIDS in certain babies. FSID’s scientific advisor, George Haycock, says that, while the new findings are important, they are unlikely to be the only risk factor.

The abnormality identified has to do with the brainstem's ability to use and recycle serotonin, a brain chemical which plays a role in communications between brain cells. Serotonin is most well known for its role in regulating mood, but it also plays a role in regulating vital functions like breathing, heart rate, blood pressure, temperature and arousal.

This can be described as a sort of “wiring” problem in the baby’s brain. When these babies are challenged by things such as rebreathing their own exhaled air (when tummy sleeping, sleeping on soft bedding, or bed sharing), overheating or exposure to tobacco, their brain does not sound an alarm to let them know to respond to the problem. They just do not wake up.

The researchers also found that male SIDS infants had fewer serotonin receptors than did either female SIDS infants or control infants. The finding may provide insight into why SIDS affects roughly twice as many males as females.

The majority (65 percent) of the SIDS cases in this data set were sleeping prone or on their side at the time of death and 23 percent were sharing a bed at the time of death, indicating the need for continued public health messages on safe sleeping practices.

Read our full press statement issued to health correspondents