A journey into the shaken baby syndrome/abusive head trauma controversy

17
May
2023

Cyrille Rossant

Cambridge University Press is publishing a textbook I have co-edited with five colleagues, Shaken Baby Syndrome, Investigating the Abusive Head Trauma Controversy, by Findley et al. With contributions by 32 authors, this book provides a thorough analysis of an interdisciplinary subject lying at the intersection of medicine, science, and law, and covering topics in pediatrics, neuropathology, biomechanics, statistics, psychology, criminal law, and many others. This is also a truly international issue, and our book explores the similarities and differences in 20 different countries across all continents. This project, which may qualify as the hardest I’ve ever completed so far, actually started with a personal drama.

Seven years ago, I was in a small room of a children’s hospital, anxiously waiting for the ER pediatrician to come back with my 5-month-old’s brain CT scan results. I was on vacation with my wife and son in the South of France. Our baby David had been fussy for a month. My mother, a general practitioner, had also noticed a rapid increase of David’s head circumference for the past weeks. She feared a neurological condition.

She was right.

The ER physician came back, shocked. “Sir, your son has blood around the brain, a so-called subdural hemorrhage. I’m afraid to tell you that your baby has been shaken.”

That my own son could be a victim of shaken baby syndrome (SBS), also known as abusive head trauma (AHT), was the most devastating thing I ever heard. Babies who are victims of this severe form of child abuse are known to die or suffer from life-long disabilities after violent shaking, and my very first thoughts concerned his health. Fortunately, the MRI scan was reassuring. David successfully underwent two neurosurgical operations and he fully recovered.

My next question was obvious: who could have ever done something so horrific to my own baby? I knew for a fact that neither my wife nor I, nor anyone in our respective families could ever do something like this. David had been cared for by a nanny for the past couple of months, and we had a hard time believing she could have done it, even if his symptoms had occurred while she was caring for him — twice. David cried very infrequently and we knew no one who had cared for him could lose their temper to such a degree. Yet, fundoscopy revealed bilateral retinal hemorrhage. The doctors at the hospital were absolutely, unconditionally 100% certain that no other cause than violent shaking could ever explain blood around the brain and at the back of the eyes. Why wouldn’t I believe them? They’re the experts.

There was one exception, though. The hospital neuropediatrician mentioned that our baby could have had a relatively rare medical condition called benign external hydrocephalus, an excess of fluid around the brain sometimes associated with subdural and retinal hemorrhage. He was not fully convinced that David had been shaken, especially given the total lack of bruises, fractures, neck injury, or any other evidence of trauma. We were totally confused.

I couldn’t live with this uncertainty any longer. But first, I had to get my son back. As a precautionary measure, the hospital followed mandatory reporting statutes and my wife and I temporarily lost custody of David. Thanks to our incredibly effective defense lawyer, we were cleared of all charges within two months, during which we stayed at the hospital 24/7 with David until we sorted out the legal procedures. I would discover much later that we actually had been lucky to be allowed to do this, as most parents are abruptly separated from their babies for months after reporting takes place.

With my baby back, my next objective was clear: to understand what actually happened to David. At this point, our nanny was being prosecuted for the shaking – but she denied and I was still not certain. Had our baby really been violently shaken by a person who failed us and him – or had he simply suffered from a treatable medical condition? I asked for a second opinion from many specialists around the world, and found that they were evenly split between SBS and external hydrocephalus. This was definitely not helpful.

I came to realize that there was a long-standing scientific controversy in the field, and I felt that I had no choice but to get to the bottom of things myself. Although I am not a medical doctor, I hold a PhD in neuroscience and am familiar with critically reading scientific literature. I decided that I would invest as much time as necessary to learn everything I possibly could on the subject. At that point, there was nothing in my life more important than finding out what had really happened to my son.

That quest soon took an unexpected turn. After reading more than 500 medical articles within a few months, I managed to obtain a relatively clear answer for my son, but that turned out to be only the very beginning of a long, perhaps even a life-long journey.

What happened is that during my literature review, I disturbingly realized that what I had been told at the hospital, namely that subdural and retinal hemorrhage in infants are almost always caused by violent shaking even in the absence of external evidence of trauma, was an assertion based on very weak scientific foundations. And yet, this “shaking hypothesis” (sometimes referred to as the theory of the “triad”, since encephalopathy is frequently associated with the other two signs, subdural and retinal hemorrhage) has been taught as though it was a proven fact to generations of physicians all over the world. Every year, thousands of children are removed from their parents, and thousands are prosecuted, convicted, and even incarcerated, on the basis of this assertion. Law professor Deborah Tuerkheimer qualifies SBS/AHT as a “medical diagnosis of murder”. The very least we should expect for an assertion this powerful is that it should be based on reliable scientific foundations.

Initially, of course, I naively believed that it was. In my own field, we strive for the highest level of detail, precision, transparency, and scrutiny at every step of the scientific process, from designing hypotheses to collecting and analyzing data to reviewing journal articles. If this is true even for the researchers in basic science who do not deal with life or death situations, one would think it would be all the more true for those who do, in fields such as aeronautics, nuclear energy, or medicine. Naturally, I believed that the very highest level of thoroughness would be the rule in forensic science and criminal law, which literally deal with the liberty or imprisonment of individuals, and in death penalty jurisdictions, even with life or death.

However, forensic medicine is a very particular subject, in that errors may remain unnoticed for a long time. A problem with a rocket or nuclear reactor can hardly go unnoticed (as we have recently seen). In general, when a medical diagnosis or treatment is invalid, observing the patient’s health status constitutes an effective feedback loop. But when the wrong person is convicted, how can we know? That a person continues to declare his or her innocence is not sufficient proof.

This lack of a reliable feedback loop may partly explain the deep problems with scientific reliability that have long been identified in forensic science, as detailed in the President’s Council of Advisors on Science and Technology’s 2016 report on Forensic Science in Criminal Courts. This report even explicitly mentions SBS/AHT as one of the types of forensic evidence that require “urgent attention” for “issues related to [its] scientific validity”. The fact remains that SBS/AHT testimonies using the “shaking hypothesis” are regularly provided in court by medical experts, despite the fact that current scientific evidence simply does not provide reliable support for it.

Let there be no misunderstanding on the point that shaking is an absolutely real and dramatic form of child abuse. Inflicted head trauma is a devastating condition and a definite cause of traumatic brain injuries, including intracranial hemorrhage. Many medical determinations of SBS/AHT are made on children who have effectively been victims of violent intentional trauma. Prevention efforts against all forms of child abuse are totally warranted.

And yet, although subdural and retinal hemorrhage may be caused by non-accidental trauma, especially when impact is involved, they simply are not specific for it: indeed, it has been demonstrated that a wide range of accidental events and medical conditions are plausible alternative causes. Particularly fragile infants may sustain severe head injuries following minor household falls. Others may suffer from genetic conditions, metabolic disorders, blood clotting abnormalities, or infections.

But in practice, extremely few medical conditions are checked for and “excluded” before concluding a diagnosis of abuse – the great majority are not checked for at all. Very often, abuse is diagnosed “by default”, because no known alternative explanation was found (or even actively sought). This is extremely dangerous, as it seems to indicate that no further medical discovery need ever be made in the future.

Overall, the clinical literature supporting the shaking hypothesis suffers from a number of severe methodological shortcomings. The main issue is circular reasoning. It is only in a small minority of “shaken baby” cases that actual shaking has been observed by independent witnesses, videotaped, or spontaneously confessed before police interrogation. Far more often, shaking is “inferred” after the observation of subdural and retinal hemorrhage in infants who are brought to the hospital by parents or caregivers. Physicians interpret these types of bleeding as markers of violent trauma. When asked about these findings, parents and caregivers generally do not provide “acceptable explanations” – but the only “acceptable explanations” today apart from shaking are multistory falls and high speed motor vehicle accidents. This being so, it is considered that parents and caregivers must be lying when they report non-traumatic events such as a sudden collapse, an unexplained respiratory arrest, or a minor fall – even though this happens in case after case.

Remarkably, neuropathological studies have shown in the past twenty years that the lesions observed in infants believed to have been shaken do not actually reflect trauma, but hypoxia. More precisely, this lack of oxygen is consistent with the clinical history that is reported in many cases (choking, respiratory distress…), but immediately rejected as “incompatible” with the shaking hypothesis. The extensive epidemiological overlap between infants with subdural and retinal hemorrhage and those who die suddenly and are labeled as sudden infant death syndrome (e.g. similar mean age (3 months), sex ratios, prematurity proportions, association with respiratory distress, risk factors…) suggests that the two conditions may share common pathophysiological pathways. In addition, biomechanics research has shown that minor impacts, such as those occurring in minor falls, generate forces significantly more intense than shaking.

The main piece of evidence of SBS/AHT, considered absolute proof of shaking, is the existence of confessions of shaking obtained during police interrogation after the diagnosis was made at the hospital and communicated to the investigators and defendant. Police officers are taught by physicians that shaking is the only possible explanation for the child’s symptoms, and that it must have occurred just before the child’s collapse. While some confessions are genuine, many are false; these can be due to police-induced suggestions, declarations of guilt intended to benefit the other parent (how many fathers have told me they sacrificed themselves to let the child go back to the other parent), confessions of minor gestures interpreted as “lying descriptions” of violent shaking, or simply the unreliability of human memory. The frequency of such false confessions is scientifically well-documented in many situations, particularly in the stressful context of the collapse or sudden death of one’s baby.

On the other hand, there exist dozens of documented cases of witness reports of shaking, videotaped shakings, and spontaneous admissions of shaking, but without subdural and retinal hemorrhage. In fact, there is virtually no known case of a reliably-documented event of violent shaking without impact of a healthy baby resulting in isolated subdural and retinal hemorrhage (additional markers of trauma would be expected in such cases). In contrast, there have been numerous cases of videotaped or witnessed short falls resulting in these very medical findings, considered “impossible” by the shaking hypothesis.

Given all this, it is scientifically untenable to claim that a child “must have been shaken” when isolated subdural and retinal hemorrhage have been found in the absence of the very few “accepted alternative explanations”. At present, the correct default in this situation is: “We don’t know”. However, how can we admit we don’t know when we “diagnose” a syndrome called “shaken baby syndrome” whenever a baby is found with subdural and retinal bleeding? Effectively, a major problem with shaken baby syndrome is its name: it conflates a set of findings with a unique and entirely hypothetical cause. In fact it was Norman Guthkelch, one of the physicians at the origins of the shaking hypothesis, who proposed many decades later the more neutral and objective term of “retino-dural hemorrhage of infancy” (RDHI).

Despite all these significant scientific reliability issues, authoritative child abuse specialists and organizations still deny the existence of a legitimate controversy. The debate is extremely polarized. The noble cause of child protection is frequently weaponized as a rhetorical tactic to prevent any scientific discussion (this common strategy even has a name). The controversy is presented as an “invention” by “unethical defense lawyers and private medical experts” (publicly labelled as “child abuse denialists”) who deny – or worse, encourage – child abuse. These types of unfounded personal attacks are pervasive in the field. For example, a reviewer recently asked the authors of an article to remove a citation of another study on the grounds that its author was (sic) a “lousy and dishonest researcher”. For Guthkelch, “while controversy is a normal and necessary part of scientific discourse, there has arisen a level of emotion and divisiveness on SBS/AHT that has interfered with our commitment to pursue the truth.”

Still, despite the conflictual appearances, a subtle paradigm shift has taken place in the mainstream opinion, which today lends some unavowed credence to those who question the shaking hypothesis. The same child abuse professionals and organizations who once openly supported the shaking hypothesis are now denying its very existence. They adamantly claim that SBS/AHT has never been diagnosed on the sole basis of unexplained subdural and retinal hemorrhage. They pretend that medical determinations of abusive head trauma (which is no longer called “shaken baby syndrome” precisely because of the controversy) always involve a careful multidisciplinary consideration of all the circumstances such as other traumatic injuries, exclusion of all known medical conditions, possible antecedents of violence or abuse.

Unfortunately, this much more reasonable public stance obfuscates the inertia of clinical and judicial practice. In fact, many frontline physicians, police officers, prosecutors, and judges continue to apply the shaking hypothesis on a daily basis. Babies presenting only unexplained subdural and retinal hemorrhage, including my own son, continue to be removed from their families, and parents and caregivers continue to be prosecuted and convicted, every single day. This fact is however not apparent when reading the current medical literature: one has to have long-lasting experience in the field and/or study the literature spanning several decades to observe this paradigm shift.

The damage inflicted on children misdiagnosed with SBS and on their families is unimaginable. In my son’s case, our nanny was eventually cleared of all charges, but it took four years for the court to recognize my son’s medical condition (a rare occurrence in France, as I later discovered) during which we were forbidden to speak to her and she was forbidden to approach children, thus losing her means of livelihood.

And yet, we were spared compared to most parents in our situation, who often endure months or even years of unjustified separation from their child. Some children end up being adopted by their foster family. Nannies near the end of their careers, mourning pregnant mothers, loving fathers are often incarcerated for years or decades. Parents commit suicide; families are torn apart. The association of affected French families, Adikia, that I am now heading, is contacted by up to 250 French families each year. I have to face a level of suffering and desperation on a daily basis that I couldn’t have thought possible before all this. I observe the same biases, the same medical errors, endlessly repeated in case after case, always for the same reason: a baby was found with subdural and retinal hemorrhage. The life of any parent, or anyone caring for an infant for even a few minutes, may be destroyed in an instant only because of the blind reliance of many professionals on this unsupported hypothesis.

While there have been more and more acquittals and reversals of convictions in the past years, making progress is still extraordinarily challenging. Defense lawyers tirelessly decipher medical reports, explore the literature, and try to educate prosecutors and judges in incredibly complex topics in pediatrics, neurology, or biomechanics. Courageous private medical experts, who face the opprobrium of the mainstream supporters, take a second look at the medical files and frequently find alternative explanations that were previously missed due to confirmation bias and tunnel vision. Every case requires years of intense, dedicated efforts by an entire team of specialized lawyers and medical experts, but there are tens of thousands of cases and few experts willing to defend them.

As underlined by Innocence Project cofounder Barry Scheck in the book’s foreword, it is essential that the public and all professionals involved in these cases comprehend the forensic unreliability of determinations of SBS/AHT. That does not mean that suspicions of child abuse shouldn’t be reported, that cases of children with unexplained traumatic injuries shouldn’t be investigated, that intentional head trauma does not occur or does not cause severe injuries. However, healthcare professionals should recognize that child abuse is a legal determination, not a medical one. While physicians have a duty to report suspicions of child abuse, asserting the “certainty” of a hypothesis without disclosing to the courts the unreliability of its scientific foundations is unethical and unacceptable.

We hope our book will help all professionals involved navigate through the literature and form a robust opinion on the current state of scientific knowledge on SBS/AHT, which will ultimately serve the interests of justice.