New Research Shows Link Between SIDS and Inner Ear Damage

Dr. Daniel Rubens, Seattle Children's Hospital Anesthesiologist
Dr. Daniel Rubens, Seattle Children’s Hospital Anesthesiologist

Two Seattle Children’s Hospital doctors have teamed up as an unlikely pair working to find an answer to one of the most elusive pediatric mysteries: what causes Sudden Infant Death Syndrome (SIDS)? One is a pediatric anesthesiologist, Dr. Daniel Rubens, the other is the Director of the Center for Integrative Brain Research, Nino Ramirez, Ph.D. With help from Travis Allen, a nurse anesthetist at Seattle Children’s, the two researchers are hoping to provide answers to families who have lost babies to SIDS and help medical professionals better understand the risk factors.

On the Pulse caught up with Rubens recently to answer a few of the most common questions about SIDS and his research.

Q: What is the research you are doing on SIDS currently in conjunction with Dr. Ramirez?

A: We are working together to identify ways to help babies who may be at risk for SIDS survive when they are asleep. So far, we hypothesize that babies with inner ear damage are not able to wake up or move themselves away from danger if their breathing is compromised. Therefore, they suffer from a lack of oxygen and build up of carbon dioxide in their bodies while asleep and they can die.

Parents can do everything correctly and this can still happen. With this in mind, we are evaluating the potential need for early specialized monitoring systems and treatments to help babies who are at risk.

Q: Many parents are confused about the difference between SIDS and suffocation. Can you explain the difference?

A: When we refer to suffocation, we are talking about the deathly gas mixtures inside the baby’s body. We are not referring to suffocation caused by something the parents could have done differently. I am referring to when a baby dies and the parents have done everything right, there is nothing more they could have done; it is not anybody’s fault.

Unfortunately, about 4,000 out of the four million babies born in the United States each year still die from SIDS. Babies can die from SIDS even if they are sleeping on their backs, in a crib alone and there is no smoking environment or any other risk factors. It’s a terrible situation and we don’t know why it happens. This is why we as researchers want to investigate and understand so that we can hopefully stop this from happening.

Q: What interested you about SIDS and why did you begin researching it?

A: My training is in pediatric anesthesiology. Therefore, children go to sleep under my clinical care all the time, so somehow I was just drawn to SIDS and the mystery of it.

When I initially began thinking about how to treat SIDS, I felt that we needed to look in places that we hadn’t looked before, such as the inner ear. I decided to look at newborn hearing data because the newborn hearing test is already universally done and does not involve any invasive procedures.

I do believe there is something different about the SIDS cases that leave babies at risk, so they are not able to respond to the lack of oxygen in their body compared to other infants.

From my research, I’ve learned that even a highly-trained anesthesiologist (with all of the monitoring that we currently have available) would struggle to resuscitate the baby with the SIDS predisposition from a fatal event. We need more sophisticated monitoring in order to pick up a potential crisis early.

Q: What infants are most at risk?

A: Many deaths due to SIDS occur between 2 and 4 months of age. The risk of SIDS drops significantly at 6 months and is considered extremely rare after 12 months of age. African-American infants are twice as likely and Native American infants are about three times more likely to die of SIDS than Caucasian infants. More boys than girls (60:40) fall victim to SIDS.

Q: Why do you think some babies die of SIDS?

A: I believe some babies have a pre-disposition to SIDS. When the baby is born, there is a problem in the inner ear, which could be related to why they die. It’s not something symptomatic that a baby shows while awake.

An important piece of the puzzle is that we do not know at this point how the inner ear damage has occurred in the first place. I suspect it happens during the birthing process, and it’s not immediately fatal, but we don’t yet know that for sure.

Q: Is there anything that can be done to detect this inner ear damage?

A: In the future, doctors could potentially use an updated version of the currently utilized newborn hearing screen test to help with early detection of the ear trauma that may be associated with SIDS predisposition at birth.

Q: What would be different about the new screening than what’s currently offered to newborns?

A: We may be able to add imaging techniques to scan for inner ear damage. The goal would be to utilize a combination of the newborn hearing test and imaging studies to allow doctors to alert parents of their child’s potential risk. I am working with Dr. Marta Cohen, a pediatric pathologist at Sheffield Children’s in the United Kingdom, to use CT and MRI imaging of the inner ear in a post mortem study to better understand how inner ear damage might have contributed to SIDS related deaths.

Q: So parents don’t currently have this screening as an option?

A: No. These tests are not currently available which is why I am trying to raise $100,000 for a large-scale hearing study.

Q: How can people help contribute to your research?

A: I started a guild named The SIDS Research Guild. Any contributions are greatly appreciated and will allow us to continue to research this heartbreaking issue.