Evidence-Based Medicine and Shaken Baby Syndrome

Drs. John Galaznik and John Plunkett, at the EBMSI conference

Evidence-based medicine (EBM) is a formal discipline intended to sort out what doctors really know from what they simply believe, “to differentiate objective data from opinion,” explained forensic pathologist Dr. John Plunkett at the second Evidence Based Medicine and Social Investigation conference earlier this month. “Evidence should always trump opinion,” he noted.

As detailed below, the EBM movement relies more on scientifically controlled research—and less on expert opinion and case studies—than the approach that’s traditionally dominated the medical literature.

The highest level of certainty under EBM guidelines applies more readily to drug trials, Plunkett said, where researchers can use large populations and appropriate controls, than to shaken baby syndrome research. “Nothing in the child-abuse literature is going to come anywhere near to Level I,” he conceded, on either side of the shaking debate. “There is not going to be a major bulletin about this.”

The arena itself constrains researchers’ ability to study infant head trauma, Plunkett said, and so the results are not reliable, with the exception of “the biomechanical studies that have been repeated over and over with the same results”—that is, that shaking without impact should not cause subdural hematoma.

Plunkett said he himself misunderstood the role of rotation for many years, even after he started doubting classic shaking theory in the 1980s. “I had been taught that rotation causes subdural hematoma, so I was looking for rotation in a fall,” he explained. “I didn’t realize it until 13 years ago:  Impact causes rotation.”

A number of test-dummy videos shown during the conference illustrated his point:  When a dummy’s head hit the floor, it would bounce back up, in an arc constrained by the neck, finally hitting the floor again at least once.

Rotational motion resulting from linear impact, from F.A. Bandak, Forensic Science International, 151 (2005) p. 75

Biomechanical engineers use the term “impulse loading” to describe the rotational forces caused by the head’s motion at the end of its tether, that is, the neck, which is attached to the trunk.

“Everything caused by impulse loading can be caused by impact,” Plunkett declared. “The reverse in not true.” While impact can cause subdural hematoma, retinal hemorrhage, and encephalopathy, for example, shaking cannot cause skull fracture.

There is simply no need to presume shaking, he said, when a child with the triad shows evidence of an impact.

Nor is shaking necessary to explain subdurals when the child shows no evidence of impact, because “Subdural collections occur without trauma.”  A number of metabolic and infectious diseases can cause them, as well as vascular malformations and any interruption of oxygen to the brain. Some causes, like Saggittal Sinus Thrombosis, are easy to diagnose, Plunkett said, but “Superficial Cortical Venous Thrombosis is routinely missed.”

He dismissed ruptured bridging veins as the source of small subdural hematomas, the “thin film” hematomas often associated with a shaking diagnosis. “Bridging veins are large-caliber conduits,” he said, carrying 5 to 10 ml. of blood per minute. “If one of these things is ruptured, you’re going to get a lot of bleeding, and you’re going to get it really fast.” He described stretch tests in which researchers were able to suspend 4 ounces—the equivalent of a stick of butter, which represents about 500 pounds per square inch—from a harvested bridging vein without snapping it.

“How do you break those without impact?” he asked, answering himself: “You don’t.”

When faced with the triad and no clear explanation, Plunkett concluded, “The default diagnosis is ‘I don’t know,’ not ‘Abusive  Head Trauma.'”

Evidence-based medicine guidelines vary in different places and contexts, but the U.S. Preventive Services Task Force defines these levels of reliability for published medical literature (from Wikipedia):

  • Level I: Evidence obtained from at least one properly designed randomized controlled trial.
  • Level II-1: Evidence obtained from well-designed controlled trials without randomization.
  • Level II-2: Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group.
  • Level II-3: Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled trials might also be regarded as this type of evidence.
  • Level III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.

The bulk of the child abuse literature is at Level III on this scale. For an evidence-based analysis of the medical literature about shaken baby syndrome, please see this journal article by Dr. Mark Donohoe.

If you are not familiar with the debate surrounding shaken baby syndrome, please see the home page of this site.

-Sue Luttner

25 Comments

Filed under abusive head trauma, AHT, Dr. John Plunkett, EBMSI conference, SBS, shaken baby syndrome

25 responses to “Evidence-Based Medicine and Shaken Baby Syndrome

  1. Audrey Edmunds

    Thank you so much, Sue for this information. I am so thankful for all those who speak out against this wrongful conviction. Audrey

    • Thank you, Audrey. I appreciate the validation.

      2013 update: Since this exchange, Audrey has published a book about her trial and decade in prison before her conviction was reversed through years of work by the Wisconsin Innocence Project.

  2. katie

    Thanks for working on this…I am speechless!

  3. “When faced with the triad and no clear explanation, Plunkett concluded, “The default diagnosis is ‘I don’t know,’ not ‘Abusive Head Trauma.’”
    The”triad” does have an explanation – Vitamin K Deficiency Disease.
    Google Dr Michael D Innis and folllow the leads,
    The Shaken Baby Syndrome and all its Morphs are fabricated diagnoses of doctors who do not understand the pathophysiology of Haemostasis (blood clottting) and Osteogenesis (bone formation)

    Michael Innis

    • Thank you, Dr. Innes, for checking in. I have heard of your valuable work, and I’m pleased to make the connection.

    • clara

      Dr. Innis me and my husband ann his daughters mother are currently being accused of SBS with his daughter. She was never shaken by any of us, and she was never checked for any vitamin deficiency or any other cause. She had been with an “ear infection” prior to this and during her infection the side of her left ear was swollen. is there anything you can do to help us. We are currently in family court where my 11 children were taken from us because the baby became ill at my home. Bt none of my children have signs of abuse. We return to family court on Oct 4, 2013 n they are trying to press crimianl charges as well.

      • Your attorney needs to get some outside medical opinions immediately. I’ve forwarded your email to Dr. Innis and sent you a separate email. Best wishes.

      • Michael Innis

        Please send me all the Hospital records includig LAB REPORTS an your accout of events and I will prepare a report pro bono
        Michael Innis

  4. The pleasure is mine Sue. I’m sure with your help we shall soon have the Diagnosis SBS banned .
    Michael

  5. Heidie

    what happens when there is no triad ever found and you are still accused of shaking your child. This happened to me. We had brought our son in to the hospital and after a CT scan were sent home. He went in with a very enlarged head but we were told that it was an excess amount of CSF and that it should absorb on it’s own. A little better than 2 weeks later we were back in the hospital for a routine follow up and MRI scan and they found bleeding. They instantly made the accusation of SBS and we were told that he would have to undergo immediate surgery to remove the hematomas. After the surgery they completed the remaining tests to confirm their thoughts of SBS but there was nothing else. His eyes were clear of damage, he had no bruising and no broken or fractured bones and his brain was actually being compressed as opposed to swelling. I am in the process of getting all medical files including CT scan and MRI films sent to me and am in need of someone to look into this.

  6. jessica janusiak

    i am not sure where to start…but thank you!!! All of this information has been very helpful to my family and i. My sister is fighting a case with sbs right now and this information helped alot….

    • Thank you for posting, Jessica. Best wishes to you and your family—please tell your sister there is a community who understands her plight. If you haven’t found the Resources page, check it out.

      • katie

        I am so sorry to hear that there are more people accused for SBS…The only thing I can tell you is to be strong mentally as well as psychologically. Do something productive to your life while waiting for the seemingly endless legal process. Please do not dwell on what the prosecutor said and what really happened – you’d drive yourself crazy if you do so. Stay healthy, strong and enthusiastic – you have to regardless of the result!!! This is what I did when I was in the system and had been falsely accused for the same. I wish your sister and your family the best!!!

      • Michael Innis

        If you send me details including all Hospital and Lab reports I will be happy to provide a report pro-bono.

      • “Please do not dwell on what the prosecutor said and what really happened.” Seriously good advice. The two are irreconcilable.

  7. Alonzo C. Leisholmn Sr.

    Dr. Michael D. Innis, my son needs help regarding his 10 month old son regarding allegations SBS, can he contact you? Or vise versa his contact is listed below. Thank you, Lucione Leisholmn

  8. Pingback: Good Medicine: Connect at a Conference | On SBS

  9. Michael Innis

    Alonzo send me the Hospital Recors and Lab reports and your account of the events and I wil take ot from there.
    Michael Innis

  10. Cheryl Rosselot

    I am just stunned at the amount of people who are so horribly effected by this diagnosis. I am currently researching and fighting for my son who is accused of SBS and his attorney doesn’t even have the slightest bit of knowledge in this area. I have been reading story after story of people’s lives being ripped apart and the medical system making judgements (mandatory reporters in the medical field) instead of really trying to find out what happened to the child. Isn’t it ultimately about the overall health and well being of the child? Nope! I’m convinced our situation is a medical one and need all the support and help I can get. I welcome anyone who has the heart to reach out and help us fight. I contacted the Innocence Project of Florida and no answer yet.

    • I’ve just sent you a private email, Cheryl. I will also post here the url to my Resources page, for other people in your position: https://onsbs.com/home/resources/

      You’re right, finding out what really caused the child’s problems is paramount. Make sure you get copies of all medical records: Pre-natal, birth, and well-baby, as well as the records surrounding whatever event led to the diagnosis. Original copies of all imaging, as well as the reports.

      Best wishes to you and your son, and to the child. It’s one of the unnecessary tragedies in these misdiagnoses of abuse by shaking, that sick children do not get the care they need.

  11. Sandra Durazo

    Thank you, I am in constant prayer as Dr Plunkett is the medical expert on my sons current case. It’s devastating to our family, we thank god for your expertise in this emotional and critical area that has not been fully disclosed. God bless you.

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