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The stories are heartbreaking: A an infant is dead, and his parent or babysitter sits in prison, accused of shaking the baby to death. Just this month in Florida, the uncle of a 17-month-old was charged with allegedly killing his nephew this way.

The National Center on Shaken Baby Syndrome estimates that some 1,300 children are hospitalized each year as a result of injuries sustained as a result of shaking. About one quarter of these babies die, and many of the others have life-altering brain damage.

The most notorious case involved the death of 8-month-old Matty Eappen in 1997, in Massachusetts. His nanny was convicted by a jury of shaking him to death, but the trial judge vacated the original conviction, unconvinced by the scientific evidence that had been presented.

Now, although there are many clear cases in which shaken children die, new research suggests that the pathology once thought to define shaken baby syndrome can also occur as a result of other causes.

The shaken baby "triad"

In the past, Shaken Baby Syndrome was defined by a "triad" of symptoms: a type of bleeding in the brain called a subdural hematoma; retinal hemorrhage (bleeding in part of the eyes); and the absence of any recent accident that could account for a severe head injury.

But while no one believes that shaking is safe, there is still debate over whether shaking alone can kill, or whether the baby's head must hit a hard object as well. As a result, experts now call the problem "abusive head trauma," avoiding any debate on the mechanical cause.

Marta Cohen, M.D., a British pathologist, is co-author of a study recently published in Pediatric and Developmental Pathology. She and her colleague examined 25 fetuses and 30 newborns who died as a result of birth injury or disease without ever having left the hospital. "It was not possible for them to have been shaken," she states.

The babies and fetuses examined by Cohen each had subdural hematomas that occurred in the absence of abuse. And although this study did not examine their eyes for retinal hemorrhage, other research has found that this, too, can occur when the brain is deprived of oxygen for other reasons.

Cohen explains that when pressure in the head is increased by brain swelling and lack of oxygen—which can have many causes—retinal bleeding is common. "My expectation is that all of these babies would have had retinal hemorrhages, not only because of [low oxygen] but also because of brain swelling."

"We don't know everything in medicine," she says, emphasizing that without additional evidence of abuse, these indicators should not be used to convict people of killing children. "If we don't know the cause of sudden infant death syndrome [SIDS], how can we say for sure that this is Shaken Baby Syndrome? To me, it's not enough evidence."

Legal versus medical standards

But Robert Reece, M.D., clinical professor of pediatrics at Tufts University, has a different perspective. A leading expert on Shaken Baby Syndrome, he calls Cohen's study "well designed and executed," but says that it's a "stretch" to extend the findings to retinal hemorrhage.

He believes that most cases that are now prosecuted are done so with significant evidence, noting that many experts tend to review the case before prosecution is even considered, because false accusations can have such tragic consequences.

"The problem is that in the courtroom, there is a black-and-white approach to the legal determination of abuse, so it becomes very difficult to get some evidence admitted because of the rules. It's a much different event than a medical diagnosis in a hospital setting," says Reece.

This conflict is inevitable: Medical diagnosis often deals with probabilities and ruling out alternative explanations, and courts need solid evidence that defies reasonable doubt.

Says Reece, "Some people think we're over-diagnosing. I do think that there are questions that are unresolved and there need to be more studies. But I would like to see the heat turned down. People are very committed to one side or another and we are not going to get answers from that kind of dialogue."

'PURPLE' crying: Education to help prevent SBS

Regardless of the legal debate surrounding SBS, the fact remains that abusive head trauma is common and there is often evidence of prior assault. In many cases of Shaken Baby Syndrome—30 to 70 percent of the time, depending on the study—there's evidence of prior abuse, obtained from child welfare or previous emergency room admissions records. And research now shows that crying is the most frequent reason cited for this type of abuse.

Two new studies of a program called "The Period of PURPLE Crying" suggest that teaching parents how to cope with prolonged crying could help. "Each letter refers to a property of crying that is normal for infants in first three to five months," says Ronald Barr, M.D., the studies' author and a professor of pediatrics at the University of British Columbia, in Vancouver.

P stands for peak, which means that crying increases though the first, second and sometimes third month, then declines. U is for unexplained: the baby isn't hungry, wet, sick or in pain. R is for resistant to soothing, meaning that the crying doesn't immediately stop, no matter what the parents or caregivers do. L is the fact that the bouts of crying are long—on average, 35 minutes. E means that the crying tends to occur in the evening or late afternoon.

The two studies found that simply handing parents information about crying increased their knowledge by 5 to 7 percent, which is a first step in changing awareness and behavior. And one of the studies found that the number of parents that walked away when frustrated—leaving the baby safely in its crib—doubled if they'd received this information.

According to Barr, teaching parents about PURPLE helps them recognize that crying won't last forever and that there isn't something wrong with them or their child.

Increased understanding may reduce frustration, which in turn can diminish the likelihood of abuse and Shaken Baby Syndrome or any other abusive trauma.

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