| |
 |
Hannah C. Kinney, MD |
In 2006, Children’s Hospital Boston neuropathologist Hannah C. Kinney, MD, and colleagues showed that sudden infant death syndrome (SIDS) is associated with abnormalities in brainstem serotonin circuits, but the details weren’t clear. A new study (JAMA, February 3, 2010) pinpoints the cause as an under-production of serotonin in the brainstem.
Using samples obtained by autopsy, the researchers compared 35 infants who died from SIDS with two control groups (five infants died acutely from other causes, and five from chronic hypoxia-ischemia). In the SIDS infants, serotonin levels in the lower brainstem were 26 percent lower, levels of tryptophan hydroxylase (the enzyme that helps make serotonin) were 22 percent lower and levels of binding to serotonin receptors were more than 50 percent lower.
Dr. Kinney believes that low serotonin levels leave infants less able to compensate for physiologic stresses during sleep, such as rebreathing carbon dioxide around the face in the prone position, or hyperthermia from over-bundling. While a normal baby would rouse to get fresh air or kick off its blanket, a baby with low serotonin levels may not.
Dr. Kinney’s lab is now investigating what causes the serotonin deficiency. Her ultimate goal is an early test to identify infants at risk, as well as preventive treatments.
|
|
| |