Evidence-based medicine and shaken baby syndrome: part I: literature review, 1966-1998

Wrongful convictions and claims of false or misleading forensic evidence

The results are reported of a study to examine case factors associated with 732 wrongful convictions classified by the National Registry of Exonerations as being associated with "False or Misleading Forensic Evidence." A forensic error typology has been developed to provide a structure for the categorization and coding of factors relating to misstatements in forensic science reports; errors of individualization or classification; testimony errors; issues relating to trials and officers of the court; and evidence handling and reporting issues. This study, which included the analysis of 1391 forensic examinations, demonstrates that most errors related to forensic evidence are not identification or classification errors by forensic scientists. When such errors are made, they are frequently associated with incompetent or fraudulent examiners, disciplines with an inadequate scientific foundation, or organizational deficiencies in training, management, governance, or resources. More often, forensic reports or testimony miscommunicate results, do not conform to established standards, or fail to provide appropriate limiting information. Just as importantly, actors within the broader criminal justice system-but not under the purview of any forensic science organization-may contribute to errors that may be related to the forensic evidence. System issues include reliance on presumptive tests without confirmation by a forensic laboratory, use of independent experts outside the administrative control of public laboratories, inadequate defense, and suppression or misrepresentation of forensic evidence by investigators or prosecutors. In approximately half of wrongful convictions analyzed, improved technology, testimony standards, or practice standards may have prevented a wrongful conviction at the time of trial.

Evidence for significant misdiagnosis of abusive head trauma in pediBIRN data

Independently witnessed events are used as a reference standard to robustly categorize accidental or non-abusive head trauma (non-AHT) cases in the pediBIRN data set of acutely symptomatic infants with closed head injuries. Findings in such independently witnessed non-AHT cases are compared to findings in cases that were diagnosed as AHT but were not independently witnessed. The data shows that 14% of independently witnessed non-AHT cases are misdiagnosed as AHT, and that risk factors for misdiagnosis include acute encephalopathy, bilateral or interhemispheric SDH, and/or severe retinal hemorrhages, findings that are commonly associated with AHT. The data also shows that "dense retinal hemorrhages extending to the periphery" are not highly suggestive of AHT, as they also occur in independently witnessed non-AHT cases.

The Eyes Have It: How Critical are Ophthalmic Findings to the Diagnosis of Pediatric Abusive Head Trauma?

Pediatric abusive head trauma (AHT), still colloquially known as shaken baby syndrome, is a leading cause of morbidity and mortality among infants. Controversy has grown surrounding this diagnosis, and the specificity of the clinical findings-subdural hemorrhage, cerebral edema, and retinal hemorrhages-has been challenged. A literature search of peer reviewed publications on PubMed pertaining to the history, clinical, and pathologic features of AHT was conducted using the terms "shaken baby syndrome," "non-accidental trauma," "abusive head trauma," "inflicted traumatic brain injury," "shaken impact syndrome," and "whiplash shaken infant syndrome." Focus was placed on articles discussing ophthalmic findings in AHT. Retinal hemorrhages-particularly those that are too numerous to count, occurring in all layers of the retina (preretinal, intraretinal, subretinal), covering the peripheral pole and extending to the ora serrata, and accompanied by retinoschisis and other ocular/periocular hemorrhages-are highly suggestive of AHT, particularly in the absence of otherwise explained massive accidental trauma. Although the diagnosis has grown in controversy in recent years, AHT has well-documented clinical and pathologic findings across a large number of studies.

Why admitted cases of AHT make a low quality reference standard: A survey of people accused of AHT in France

Several influential articles that attempt to establish diagnostic methods for Abusive Head Trauma (AHT) use admitted cases as a reference standard. This study analyses a survey of people accused of AHT in France, to understand the environment and situations in which such admissions are made. Multiple reasons to question the reliability of admissions to AHT are demonstrated in the responses, including reduced sentences, the return of children to the family home, a desire to stop accusations being leveled at a partner and for legal proceedings to end. These factors must be considered in the context of proceedings that are long, expensive and stressful, leading to depression and financial hardship, and that seem to be inevitably heading towards conviction. The ineluctable conclusion is that admitted cases do not make a suitably reliable reference standard for undertaking scientific investigation, or for validating the diagnostic methods used for AHT.

Re-evaluation of medical findings in alleged shaken baby syndrome and abusive head trauma in Norwegian courts fails to support abuse diagnoses

AIM

The criteria for diagnosing abusive head trauma (AHT) are not well defined and this condition might be diagnosed on failing premises. Our aim was to review criminal AHT cases in Norwegian courts by scrutinising the underlying medical documentation.

METHODS

Cases were identified in the data registry for Norwegian courts from 2004 to 2015. Documentation was obtained from relevant health institutions. The medical co-authors first made independent evaluations of the documentation for each child, followed by a consensus evaluation.

RESULTS

A total of 17 children (11 boys) were identified, all diagnosed as AHT by court appointed experts, 15 were infants (mean age 2.6 months). A high proportion (41.2%) was born to immigrant parents and 31.3% were premature. The medical findings could be explained by alternative diagnoses in 16 of the 17 children; 8 boys (7 infants - mean age 2.9 months) had clinical and radiological characteristics compatible with external hydrocephalus complicated by chronic subdural haematoma. Six children (five infants with mean age 2.1 months) had a female preponderance and findings compatible with hypoxic ischaemic insults.

CONCLUSION

The medical condition in most children had not necessarily been caused by shaking or direct impact, as was originally concluded by the court experts.

Is external hydrocephalus a possible differential diagnosis when child abuse is suspected?

Background

Criteria for diagnosing abusive head trauma (AHT) or “shaken baby syndrome” are not well defined; consequently, these conditions might be diagnosed on failing premises.

Methods

The authors have collected a total of 28 infants, from the US (20) and Norway (8), suspected of having been violently shaken, and their caregivers had been suspected, investigated, prosecuted or convicted of having performed this action. Among 26 symptomatic infants, there were 18 boys (69%) and 8 girls (31%)—mean age 5.1 month, without age difference between genders.

Results

Twenty-one of 26 symptomatic children (81%) had a head circumference at or above the 90 percentile, and 18 had a head circumference at or above the 97 percentile. After macrocephaly, seizure was the most frequent initial symptom in 13 (50%) of the symptomatic infants. Seventeen (65%) of the symptomatic infants had bilateral retinal haemorrhages, and two had unilateral retinal haemorrhages. All infants had neuroimaging compatible with chronic subdural haematomas/hygromas as well as radiological characteristics compatible with benign external hydrocephalus (BEH).

Conclusions

BEH with subdural haematomas/hygromas in infants may sometimes be misdiagnosed as abusive head trauma. Based on the authors’ experience and findings of the study, the following measures are suggested to avoid this diagnostic pitfall: medical experts in infant abuse cases should be trained in recognising clinical and radiological BEH features, clinicians with neuro-paediatric experience should always be included in the expert teams and reliable information about the head circumference development from birth should always be available.

Animal models of pediatric abusive head trauma

BACKGROUND

Abusive head trauma (AHT), previously known as the shaken baby syndrome, is a severe and potentially fatal form of traumatic brain injury in infant children who have been shaken, and sometimes also sustained an additional head impact. The clinical and autopsy findings in AHT are not pathognomonic and, due to frequent obfuscation by perpetrators, the circumstances surrounding the alleged abuse are often unclear. The concept has evolved that the finding of the combination of subdural hemorrhage, brain injury, and retinal hemorrhages ("the triad") is the result of shaking of an infant ("shaken baby syndrome") and has led to the ongoing controversy whether shaking alone is able to generate sufficient force to produce these lesions.

OBJECTIVE

In an attempt to investigate whether shaking can engender this lesion triad, animal models have been developed in laboratory rodents and domestic animal species. This review assesses the utility of these animal models to reliably reproduce human AHT pathology and evaluate the effects of shaking on the immature brain.

RESULTS

Due largely to irreconcilable anatomic species differences between these animal brains and human infants, and a lack of resemblance of the experimental head shaking induced by mechanical devices to real-world human neurotrauma, no animal model has been able to reliably reproduce the full range of neuropathologic AHT changes.

CONCLUSION

Some animal models can simulate specific brain and ophthalmic lesions found in human AHT cases and provide useful information on their pathogenesis. Moreover, one animal model demonstrated that shaking of a freely mobile head, without an additional head impact, could be lethal, and produce significant brain pathology.

Mild abusive head injury: diagnosis and pitfalls

Clinicians often miss making the diagnosis of abusive head injury in infants and toddlers who present with mild, non-specific symptoms such as vomiting, fussiness, irritability, trouble sleeping and eating, and seizure. If abusive head injury is missed, the child is likely to go on to experience more severe injury. An extensive review of the medical literature was done to summarize what is known about missed abusive head injury and about how these injuries can be recognized and appropriately evaluated. The following issues will be addressed: the definition of mild head injury, problems encountered when clinicians evaluated mildly ill young children with non-specific symptoms, the risk of missing the diagnosis of mild abusive head trauma, the risks involved in subjecting infants and young children to radiation and/or sedation required for neuroimaging studies, imaging options for suspected neurotrauma in children, clinical prediction rules for evaluating mild head injury in children, laboratory tests than can be helpful in diagnosing mild abusive head injury, history and physical examination when diagnosing or ruling out mild abusive head injury, social and family factors that could be associated with abusive injuries, and interventions that could improve our recognition of mild abusive head injuries. Relevant literature is described and evaluated. The conclusion is that abusive head trauma remains a difficult diagnosis to identify in mildly symptomatic young children.

Determining the Tractional Forces on Vitreoretinal Interface Using a Computer Simulation Model in Abusive Head Trauma

PURPOSE

Abusive head trauma (AHT) is the leading cause of infant death and long-term morbidity from injury. The ocular consequences of AHT are controversial, and the pathophysiology of retinal research findings is still not clearly understood. It has been postulated that vitreoretinal traction plays a major role in the retinal findings. A computer simulation model was developed to evaluate the vitreoretinal traction and determine whether the distribution of forces in different layers and locations of the retina can explain the patterns of retinal hemorrhage (RH) seen in AHT.

DESIGN

Computer simulation model study.

METHODS

A computer simulation model of the pediatric eye was developed to evaluate preretinal, intraretinal, and subretinal stresses during repetitive shaking. This model was also used to examine the forces applied to various segments along blood vessels.

RESULTS

Calculated stress values from the computer simulation ranged from 3-16 kPa at the vitreoretinal interface through a cycle of shaking. Maximal stress was observed at the periphery of the retina, corresponding to areas of multiple vessel bifurcations, followed by the posterior pole of the retina. Stress values were similar throughout all 3 layers of the retina (preretinal, intraretinal, and subretinal layers).

CONCLUSIONS

Ocular manifestations from AHT revealed unique retinal characteristics. The model predicted stress patterns consistent with the diffuse retinal hemorrhages (RH) typically found in the posterior pole and around the peripheral retina in AHT. This computer model demonstrated that similar stress forces were produced in different layers of the retina, consistent with the finding that retinal hemorrhages are often found in multiple layers of the retina. These data can help explain the RH patterns commonly found in AHT.

Medicolegal issues in abusive head trauma for the pediatric neurosurgeon

The purpose of this article is to serve as a rational guide for the pediatric neurosurgeon in navigating common medicolegal issues that arise in the management of abusive head trauma (AHT). Many of these issues may be unfamiliar or unpleasant to surgeons focused on addressing disease. The authors begin with a brief history on the origins of the diagnosis of AHT and the controversy surrounding it, highlighting some of the facets of the diagnosis that make it particularly unique in pediatric neurosurgery. They then review some special medical considerations in these patients through the perspective of the neurosurgeon and provide several examples as illustration. The authors discuss how to appropriately document these cases in the medical record for expected legal review, and last, they provide an overview of the legal process through which the neurosurgeon may be called to provide testimony.

Ethical Testimony in Cases of Suspected Child Maltreatment: The Ray E. Helfer Society Guidelines

New guidelines for ethical testimony were developed by the Ray E. Helfer Society, the largest medical professional society for physicians working in the field of child maltreatment. Building on the foundation of ethical guidelines set forth by the American Academy of Pediatrics, these new guidelines set detailed standards for testifying in cases of suspected child maltreatment and recommend that hospitals, medical practices, academic institutions, and professional societies hold their members accountable for court testimony related to child maltreatment as with other forms of medical practice and expert testimony.

Child abuse and the pediatric surgeon: A position statement from the Trauma Committee, the Board of Governors and the Membership of the American Pediatric Surgical Association

BACKGROUND

The pediatric surgeon is in a unique position to assess, stabilize, and manage a victim of child physical abuse (formerly nonaccidental trauma [NAT]) in the setting of a formal trauma system.

METHODS

The American Pediatric Surgical Association (APSA) endorses the concept of child physical abuse as a traumatic disease that justifies the resource utilization of a trauma system to appropriately evaluate and manage this patient population including evaluation by pediatric surgeons.

RESULTS

APSA recommends the implementation of a standardized tool to screen for child physical abuse at all state designated trauma or ACS verified trauma and children's surgery hospitals. APSA encourages the admission of a suspected child abuse patient to a surgical trauma service because of the potential for polytrauma and increased severity of injury and to provide reliable coordination of services. Nevertheless, APSA recognizes the need for pediatric surgeons to participate in a multidisciplinary team including child abuse pediatricians, social work, and Child Protective Services (CPS) to coordinate the screening, evaluation, and management of patients with suspected child physical abuse. Finally, APSA recognizes that if a pediatric surgeon suspects abuse, a report to CPS for further investigation is mandated by law.

CONCLUSION

APSA supports data accrual on abuse screening and diagnosis into a trauma registry, the NTDB and the Pediatric ACS TQIP® for benchmarking purposes and quality improvement.

Infant abuse diagnosis associated with abusive head trauma criteria: incidence increase due to overdiagnosis?

Background

The hypothesis of this study is that the diagnosis of infant abuse is associated with criteria for shaken baby syndrome (SBS)/abusive head trauma (AHT), and that that changes in incidence of abuse diagnosis in infants may be due to increased awareness of SBS/AHT criteria.

Methods

This was a population-based register study. Setting: Register study using the Swedish Patient Register, Medical Birth Register, and Cause of Death Register. The diagnosis of infant abuse was based on the International Classification of Diseases, 9th and 10th revision. Participants: All children born in Sweden during 1987-2014 with a follow-up until 1 year of age (N = 2 868 933). SBS/AHT criteria: subdural haemorrhage, cerebral contusion, skull fracture, convulsions, retinal haemorrhage, fractures rib and long bones. Outcomes: Incidence, rate ratios, aetiologic fractions and Probit regression analysis.

Results

Diagnosis of infant abuse was strongly associated with SBS/AHT criteria, but not risk exposure as region, foreign-born mother, being born preterm, multiple birth and small for gestational age. The incidence of infant abuse has increased tenfold in Sweden since the 1990s and has doubled since 2008, from 12.0 per 100 000 infants during 1997-2007 to 26.5/100 000 during 2008-2014, with pronounced regional disparities.

Conclusions

Diagnosis of infant abuse is related to SBS/AHT criteria. The increase in incidence coincides with increased medical preparedness to make a diagnosis of SBS/AHT. Hidden statistics and a real increase in abuse are less plausible. Whether the increase is due to overdiagnosis cannot be answered with certainty, but the possibility raises ethical and medico-legal concerns.

Consensus statement on abusive head trauma in infants and young children

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. A multidisciplinary team bases this diagnosis on history, physical examination, imaging and laboratory findings. Because the etiology of the injury is multifactorial (shaking, shaking and impact, impact, etc.) the current best and inclusive term is AHT. There is no controversy concerning the medical validity of the existence of AHT, with multiple components including subdural hematoma, intracranial and spinal changes, complex retinal hemorrhages, and rib and other fractures that are inconsistent with the provided mechanism of trauma. The workup must exclude medical diseases that can mimic AHT. However, the courtroom has become a forum for speculative theories that cannot be reconciled with generally accepted medical literature. There is no reliable medical evidence that the following processes are causative in the constellation of injuries of AHT: cerebral sinovenous thrombosis, hypoxic-ischemic injury, lumbar puncture or dysphagic choking/vomiting. There is no substantiation, at a time remote from birth, that an asymptomatic birth-related subdural hemorrhage can result in rebleeding and sudden collapse. Further, a diagnosis of AHT is a medical conclusion, not a legal determination of the intent of the perpetrator or a diagnosis of murder. We hope that this consensus document reduces confusion by recommending to judges and jurors the tools necessary to distinguish genuine evidence-based opinions of the relevant medical community from legal arguments or etiological speculations that are unwarranted by the clinical findings, medical evidence and evidence-based literature.

National study shows that abusive head trauma mortality in Sweden was at least 10 times lower than in other Western countries

AIM

The validity of the diagnostic criteria for abusive head trauma (AHT) and its attributes has been widely debated. This national study investigated the possibility of false-positive and false-negative cases of fatal AHT in Sweden.

METHOD

This was a retrospective evaluation of the records of 733 deceased infants up to the age of 365 days who were examined during 1994-2013 at the six forensic medicine departments. All the records were scrutinised for possible cases of AHT.

RESULTS

We included 12 cases, of which eight had been diagnosed as AHT. Of these 12 infants, eight had a concomitant disease or perinatal illness, five were born prematurely and three were twins. Figures from other Western countries would suggest 6-7 deaths per 100,000 per year in Sweden, but in reality, there was a maximum possible incidence of 0.6 per 100,000 infants per year.

CONCLUSION

The risk of unreported fatal AHT in Sweden was low, and there may have been cases misdiagnosed as AHT. The at least 10 times lower incidence than has been reported from other Western countries, raises the question if previously reported higher incidences of fatal AHT have been exaggerated.

Are There Hallmarks of Child Abuse? I. Osseous Injuries

Fractures are commonly found in cases regarded as child abuse. The most commonly encountered fractures are to the ribs and the metaphyses. This paper examines the specificity of the classical metaphyseal lesion (CML) and rib fractures as hallmarks of child abuse. Recently, vitamin D deficiency (rickets) has been proposed as an alternative cause for the appearances typically described in CML. The literature in this area is examined. Rib fractures have also been highly associated with child abuse, particularly posterior rib fractures. As well as metabolic bone disease, resuscitation has been examined as a cause of rib fractures in young children. The current literature remains strongly supportive of rib fractures and metaphyseal fractures being indicators of child abuse.

Acceptance of Shaken Baby Syndrome and Abusive Head Trauma as Medical Diagnoses

OBJECTIVE

To assess the current general acceptance within the medical community of shaken baby syndrome (SBS), abusive head trauma (AHT), and several alternative explanations for findings commonly seen in abused children.

STUDY DESIGN

This was a survey of physicians frequently involved in the evaluation of injured children at 10 leading children's hospitals. Physicians were asked to estimate the likelihood that subdural hematoma, severe retinal hemorrhages, and coma or death would result from several proposed mechanisms.

RESULTS

Of the 1378 physicians surveyed, 682 (49.5%) responded, and 628 were included in the final sample. A large majority of respondents felt that shaking with or without impact would be likely or highly likely to result in subdural hematoma, severe retinal hemorrhages, and coma or death, and that none of the alternative theories except motor vehicle collision would result in these 3 findings. SBS and AHT were comsidered valid diagnoses by 88% and 93% of the respondents, respectively.

CONCLUSIONS

Our empirical data confirm that SBS and AHT are still generally accepted by physicians who frequently encounter suspected child abuse cases, and are considered likely sources of subdural hematoma, severe retinal hemorrhages, and coma or death in young children. Other than a high-velocity motor vehicle collision, no alternative theories of causation for these findings are generally accepted.

Exploring the controversy in child abuse pediatrics and false accusations of abuse

There is a controversy in child abuse pediatrics between an established corps of child abuse pediatricians aligned with hospital colleagues and law enforcement, and a multi-specialty challenger group of doctors and other medical professionals working with public interest lawyers. The latter group questions the scientific validity of the core beliefs of child abuse pediatricians and believes that there are a substantial number of false accusations of abuse occurring. An unproven primary hypothesis, crafted around 1975 by a small group of pediatricians with an interest in child abuse, lies at the foundation of child abuse pediatrics. With no scientific study, it was hypothesized that subdural hemorrhage (SDH) and retinal hemorrhage (RH) were diagnostic of shaking abuse. That hypothesis became the so-called "shaken baby syndrome." Through the period 1975-1985, in a coordinated manner, these child abuse specialists coalesced under the American Academy of Pediatrics and began working with district attorneys and social workers, informing them of the ways in which their hypothesis could be applied to prosecutions of child abuse and life-altering social service interventions. In a legal context, using then-prevailing evidentiary rules which treated scientific expert testimony as valid if it was "generally accepted" in the field, they represented falsely that there was general acceptance of their hypothesis and therefore it was valid science. As the ability to convict based on this unproven prime hypothesis (SDH and RH equals abuse) increased, some defense attorneys were professionally compelled by their own doubts to reach out to experts from other fields with experience with SDH and RH, trauma, and biomechanics, for second opinions. Medical and legal challenges to the established thinking soon emerged, based on both old and new evidenced-based literature. As the intensity of the controversy increased, the probability of false accusation became more apparent and the need to address the issue more pressing. Since false accusations of child abuse are themselves abusive, efforts to eliminate such false accusations must continue.

International issues in abusive head trauma

In the decades since Dr. John Caffey described a series of children with chronic subdural hematoma and long bone fractures, there has been a substantial increase in the medical recognition of various forms child abuse. In the United States, the term shaken baby syndrome was coined to explain a constellation of injuries assumed to be the result of violent shaking of infants. After improved understanding of the variety of mechanisms that occur when children are abused, abusive head trauma (AHT) has become the recommended terminology. AHT is a more comprehensive term that reflects the brain injuries that children suffer as the result of abuse. AHT continues to include shaking as a mechanism of injury as well as shaking with impact, impact alone, crushing injuries or combinations of several mechanisms. The medical community in the United States has led the way in developing new terminology and research to describe this unique and devastating form of abuse. The globalization of medicine and rapid information transfer has resulted in AHT becoming well-recognized internationally as a form of serious and fatal child abuse. This paper will review the historical basis in the United States for the diagnosis of AHT. We will also review some of the current international issue in epidemiology, diagnosis, legal processes and outcomes in selected countries/regions where child abuse physicians are actively involved in the evaluation of AHT.

Ethical Issues in Forensic Testimony Involving Abusive Head Trauma

Medical examiners provide critical diagnostic and testimonial information in abusive head trauma cases. Courtroom challenges to these diagnostic criteria and contested expert testimony have raised concerns about ethical and professional conduct of practitioners. Legal evidentiary standards for expert testimony, ethical guidelines established by medical organizations, and proposed standards for ethical practice provide a background for examination of several common challenges and testimonial claims in these cases.

Neuropathological changes in a lamb model of non-accidental head injury (the shaken baby syndrome)

Non-accidental head injury (NAHI), also termed the "shaken baby syndrome", is a major cause of death and severe neurological dysfunction in children under three years of age, but it is debated whether shaking alone is sufficient to produce brain injury and mortality or whether an additional head impact is required. In an attempt to resolve this question, we used a lamb model of NAHI since these animals have a relatively large gyrencephalic brain and weak neck muscles resembling those of a human infant. Three anaesthetised lambs of lower body weight than others in the experimental group died unexpectedly after being shaken, proving that shaking alone can be lethal. In these lambs, axonal injury, neuronal reaction and albumin extravasation were widely distributed in the hemispheric white matter, brainstem and at the craniocervical junction, and of much greater magnitude than in higher body weight lambs which did not die. Moreover, in the eyes of these shaken lambs, there was damage to retinal inner nuclear layer neurons, mild, patchy ganglion cell axonal injury, widespread Muller glial reaction, and uveal albumin extravasation. This study proved that shaking of a subset of lambs can result in death, without an additional head impact being required.

Suspicious childhood injury: formulation of forensic opinion

Child protection paediatricians have a role as forensic experts in the context of suspicious childhood injury. The task of forensic evaluation of suspicious injury is to reach a conclusion to support legal proceedings. For each injury, one of four conclusions should be reached: 1 The injury has been caused by another person and is considered to have been inflicted. 2 The injury is adequately explained by the circumstances of the injury event provided (by the carer or other witnesses). 3 The injury is self-inflicted - has been caused by the child's own behaviour as a result of normal childhood activity (with no other person actively involved). 4 The mechanism or sequence of events leading to the injury remains indeterminate or unclear. An additional consideration is determining the extent to which an injury incident was foreseeable and therefore preventable, to form an opinion on whether lack of care (neglect) is involved. Opinions reflect a body of knowledge in forensic and medical literature of known mechanisms of injury including biomechanical aspects of tissue injury in trauma scenarios. Limitations in using research documenting injury type and prevalence at different developmental stages is discussed and in particular, the application of such research to support a conclusion that the injury must have been inflicted. Emerging recognition of research documenting injuries that overlap with those found in populations of children thought to have been physically assaulted creates some doubt on previous opinions regarding exclusivity of certain findings in children definitively indicating 'abuse'. Forensic paediatricians should remain objective, limit their opinions to what can be confidently stated and exercise caution where reasonable doubt exists and avoid speculation.

Imaging of nonaccidental injury and the mimics: issues and controversies in the era of evidence-based medicine

Because of the controversy involving the determination of child abuse, or nonaccidental injury (NAI), radiologists must be familiar with the issues, literature, and principles of evidence-based medicine to understand the role of imaging. Children with suspected NAI must receive protective evaluation along with a timely and complete clinical and imaging work-up. Imaging findings cannot stand alone and must be correlated with clinical findings, laboratory testing, and pathologic and forensic examinations. Only the child protection investigation may provide the basis for inflicted injury in the context of supportive clinical, imaging, biomechanical, or pathology findings.

A systematic review of the diagnostic accuracy of ocular signs in pediatric abusive head trauma

TOPIC

To review systematically the diagnostic accuracy of various ocular signs for pediatric abusive head trauma (AHT).

CLINICAL RELEVANCE

Intraocular hemorrhages (IOH), perimacular retinal folds, traumatic retinoschisis and optic nerve sheath hemorrhages have been reported as cardinal signs of AHT. The evidence base supporting the accuracy of this interpretation, however, has not been systematically reviewed.

METHODS

A systematic keyword search of MEDLINE, EMBASE, and Evidence-Based Medicine Reviews was conducted for original studies reporting ocular findings in AHT. Articles were graded using a checklist for systematic reviews of diagnostic accuracy.

RESULTS

The initial search yielded 971 articles, of which 55 relevant studies were graded, and 20 studies met inclusion criteria and were included in the review. The overall sensitivity of IOH for AHT was 75% and their specificity was 94%. Intraretinal hemorrhage at the posterior pole was the most common finding, although extensive, bilateral, and multilayered IOH were the most specific for AHT. Optic nerve sheath hemorrhages had a sensitivity and specificity for AHT of 72% and 71%, respectively. Traumatic retinoschisis and perimacular retinal folds were reported in 8% and 14% of AHT, respectively, but were not reported in other conditions.

CONCLUSIONS

Prospective, consecutive studies confirm that IOH in infants-particularly bilateral, extensive, and multilayered-are highly specific for AHT. Optic nerve sheath hemorrhages are significantly more common in AHT than in other conditions, in autopsy studies. Traumatic retinoschisis and perimacular folds are present in a minority of AHT, but rarely seen in other conditions.

Infant acute life-threatening event--dysphagic choking versus nonaccidental injury

A 4-month-old male infant presented to the emergency room with a history of choking while bottle feeding at home, and was found by emergency medical services (EMS) to be apneic and pulseless. He subsequently developed disseminated intravascular coagulopathy and died. Computed tomography (CT) and magnetic resonance imaging (MRI) showed subdural hemorrhages (SDHs), subarachnoid hemorrhage (SAH), and retinal hemorrhages (RHs), along with findings of hypoxic-ischemic encephalopathy (HIE). The caretaker account appeared to be inconsistent with the clinical and imaging features, and a diagnosis of nonaccidental injury with "shaken baby syndrome" was made. The autopsy revealed diffuse anoxic central nervous system (CNS) changes with marked edema, SAH, and SDH, but no evidence of "CNS trauma." Although NAI could not be ruled out, the autopsy findings provided further evidence that the child's injury could result from a dysphagic choking type of acute life threatening event (ALTE) as consistently described by the caretaker.

Violence is not necessary to produce subdural and retinal haemorrhage: a reply to Puntet al

In this article we reply to the recent critique by Punt et al. in Pediatric Rehabilitation. Our hypothesis about the pathogenesis of intracranial bleeding in infants has three important implications. First, in the case of an infant with a swollen brain, subdural and retinal haemorrhage but no objective evidence of trauma, the findings by themselves are not certain evidence of abuse; second, violence is not necessary to produce subdural and retinal haemorrhage; and lastly, non-traumatic events producing apnoea with a catastrophic rise in intracranial pressure could produce a clinical picture identical to that seen in trauma.

Fatal head injury in children younger than 2 years in New York City and an overview of the shaken baby syndrome

CONTEXT

Shaken baby syndrome is a controversial topic in forensic pathology. Some forensic pathologists state that shaking alone is insufficient to explain death and that an impact must have occurred even if there is no impact site on the head.

OBJECTIVE

To examine a large cohort of fatal, pediatric head injuries for patterns of specific autopsy findings and circumstances that would support or dispute pure shaking as the cause of death.

DESIGN

We retrospectively reviewed 59 deaths due to head injuries in children younger than 2 years certified in our office during a 9 year period (1998-2006). The review included autopsy, toxicology, microscopy, neuropathology, and police and investigators' reports.

RESULTS

There were 46 homicides, 8 accidents, and 1 undetermined death from blunt-impact injury of the head. In 10 (22%) of the homicides, there was no impact injury to the head, and the cause of death was certified as whiplash shaking. In 4 (40%) of these 10 deaths, there was a history of shaking. In 5 (83%) of the other 6, there was no history of any purported accidental or homicidal injury. All 8 accidental deaths had impact sites. Of the 59 deaths, 4 (6.7%) had only remote injuries (chronic subdural hematomas, remote long bone fractures) that were certified as undetermined cause and manner. These 4 deaths were excluded from the study.

CONCLUSIONS

We describe a subset of fatal, nonaccidental head-injury deaths in infants without an impact to the head. The autopsy findings and circumstances are diagnostic of a nonimpact, shaking mechanism as the cause of death. Fatal, accidental head injuries in children younger than 2 years are rare.

Traumatic spinal cord injury: accidental versus nonaccidental injury

A 21-month-old boy with steroid-dependent asthma presented to the emergency room with Glascow Coma Score (GCS) 3 and retinal hemorrhages. He was found to have subdural and subarachnoid hemorrhage on computed tomography plus findings of hypoxic-ischemic encephalopathy (HIE). The caretaker history was thought to be inconsistent with the clinical and imaging features, and the patient was diagnosed with nonaccidental injury (NAI) and "shaken baby syndrome." The autopsy revealed a cranial impact site and fatal injury to the cervicomedullary junction. Biomechanical analysis provided further objective support that, although NAI could not be ruled out, the injuries could result from an accidental fall as consistently described by the caretaker.

Shaken baby syndrome: re-examination of diffuse axonal injury as cause of death

The discussion surrounding shaken baby syndrome (SBS) arose from the lack of evidence implicating diffuse axonal injury (DAI) as a cause of death. It was assumed instead that injury to the cervical cord, medulla, and nerve roots played a causal role. The present pathomorphological study examines 18 selected infants (<1-year-old) whose deaths were highly suspicious for SBS, exhibiting the classical SBS triad of acute subdural hemorrhage (SDH), retinal bleeding, and encephalopathy. Gross autopsy and microscopic findings of these infants were compared with those of 19 victims of sudden infant death syndrome (SIDS; control group 1) and of 14 infants who died of disease or injuries/violence not involving the head, neck or eyes (control group 2). Symptoms of mechanical impact to the head were evident in seven of the SBS infants, but in none of the control infants. DAI was not detected in either the SBS or control cases. Localized axonal injury (AI) was regularly present in the brains of the SBS infants surviving longer than 1.5-3.0 h, but only occasionally in the craniocervical junction and within the nerve roots of the upper cervical cord; it was never present in the medulla. Epidural hemorrhage of the cervical cord was seen in four of the ten examined SBS cases, but in none of the control cases. Based on the absence of DAI in the brain and of signs of generalized cervical cord or nerve root injuries, we conclude that the cause of death in the SBS victims was a global cerebral ischemia secondary to SDH, focal vasospasm, trauma-induced transitory respiratory and/or circulatory failure.

Shaken baby syndrome: the quest for evidence

Shaken baby syndrome (SBS), characterized by the triad of subdural haemorrhage, retinal haemorrhage, and encephalopathy, was initially based on the hypothesis that shaking causes tearing of bridging veins and bilateral subdural bleeding. It remains controversial. New evidence since SBS was first defined three decades ago needs to be reviewed. Neuropathology shows that most cases do not have traumatic axonal injury, but hypoxic-ischaemic injury and brain swelling. This may allow a lucid interval, which traumatic axonal injury will not. Further, the thin subdural haemorrhages in SBS are unlike the thick unilateral space-occupying clots of trauma. They may not originate from traumatic rupture of bridging veins but from vessels injured by hypoxia and haemodynamic disturbances, as originally proposed by Cushing in 1905. Biomechanical studies have repeatedly failed to show that shaking alone can generate the triad in the absence of significant neck injury. Impact is needed and, indeed, seems to be the cause of the majority of cases of so-called SBS. Birth-related subdural bleeds are much more frequent than previously thought and their potential to cause chronic subdural collections and mimic SBS remains to be established.

Nonaccidental head trauma in infants

BACKGROUND

Nonaccidental head trauma in infants is the leading cause of infant death from injury.

RESULTS AND DISCUSSION

Clinical features that suggest inflicted head trauma include the triad of the so-called shaken baby syndrome, consisting of retinal hemorrhage, subdural, and/or subarachnoid hemorrhage in an infant with little signs of external trauma. Studies have shown that, in general, the average short fall in the home is extremely unlikely to produce either subdural or retinal hemorrhage, although focal injuries such as skull fractures and epidural hemorrhage may be seen. Acceleration/deceleration, especially of the rotational type, is believed to be the most probable mechanism of injury in cases of nonaccidental head trauma. Damage to the cervicomedullary junction and the respiratory centers, with subsequent hypoxia and intracerebral edema, has also been implicated. After the initial trauma and hemorrhage, loss of cerebral autoregulation, breakdown of the blood-brain barrier, and disruption of ionic homeostasis occur, leading to brain edema and cytotoxicity. Cellular damage can involve large volumes of tissue, without respecting vascular territories.

CONCLUSION

Overall, a satisfactory biomechanical model is lacking, and the criminal nature of abusive injury makes it difficult to perform systematic, controlled studies. Unfortunately, outcomes are poor, and the rate of repeated abusive episodes is high. Future research should focus on the development of a satisfactory research model and on prevention strategies.

Mechanisms, clinical presentations, injuries, and outcomes from inflicted versus noninflicted head trauma during infancy: results of a prospective, multicentered, comparative study

OBJECTIVE

Our goal was to conduct a prospective, multicentered, comparative study that would objectively verify and explain observed differences in short-term neurodevelopmental outcomes after inflicted versus noninflicted head trauma.

METHODS

Children <36 months of age who were hospitalized with acute head trauma confirmed by computed tomography imaging were recruited at multiple sites. Extensive clinical data were captured prospectively, subjects were examined, cranial imaging studies were blindly reviewed, and caregivers underwent scripted interviews. Follow-up neurodevelopmental evaluations were completed 6 months after injury. Head-trauma etiology and mechanisms were categorized by using objective a priori criteria. Thereafter, subject groups with inflicted versus noninflicted etiologies were compared.

RESULTS

Fifty-four subjects who met the eligibility criteria were enrolled at 9 sites. Of 52 surviving subjects, 27 underwent follow-up assessment 6 months after injury. Etiology was categorized as noninflicted in 30 subjects, inflicted in 11, and undetermined in 13. Compared with subjects with noninflicted head trauma, subjects with inflicted head trauma (1) more frequently experienced noncontact injury mechanisms, (2) sustained greater injury depth, (3) more frequently manifested acute cardiorespiratory compromise, (4) had lower initial Glasgow Coma Scale scores, (5) experienced more frequent and prolonged impairments of consciousness, (6) more frequently demonstrated bilateral, hypoxic-ischemic brain injury, (7) had lower mental developmental index scores 6 months postinjury, and (8) had lower gross motor quotient scores 6 months postinjury.

CONCLUSIONS

Compared with infants with noninflicted head trauma, young victims of inflicted head trauma experience more frequent noncontact injury mechanisms that result in deeper brain injuries, cardiorespiratory compromise, diffuse cerebral hypoxia-ischemia, and worse outcomes.

Infant brain subjected to oscillatory loading: material differentiation, properties, and interface conditions

Past research into brain injury biomechanics has focussed on short duration impulsive events as opposed to the oscillatory loadings associated with Shaken Baby Syndrome (SBS). A series of 2D finite element models of an axial slice of the infant head were created to provide qualitative information on the behaviour of the brain during shaking. The test series explored variations in subarachnoid cerebrospinal fluid (CSF) representation, brain matter stiffness, dissipation, and nonlinearity, and differentiation of brain matter type. A new method of CSF modelling based on Reynolds lubrication theory was included to provide a more realistic brain-CSF interaction. The results indicate that solid CSF representation for this load regime misrepresents the phase lag of displacement, and that the volume of subarachnoid CSF, and inclusion of thickness variations due to gyri, are important to the resultant behavior. Stress concentrations in the deep brain are reduced by fluid redistribution and gyral contact, while inclusion of the pia mater significantly reduces cortex contact strains. These results provide direction for future modelling of SBS.

Imaging of the central nervous system in suspected or alleged nonaccidental injury, including the mimics

Because of the widely acknowledged controversy in nonaccidental injury, the radiologist involved in such cases must be thoroughly familiar with the imaging, clinical, surgical, pathological, biomechanical, and forensic literature from all perspectives and with the principles of evidence-based medicine. Children with suspected nonaccidental injury versus accidental injury must not only receive protective evaluation but also require a timely and complete clinical and imaging workup to evaluate pattern of injury and timing issues and to consider the mimics of abuse. All imaging findings must be correlated with clinical findings (including current and past medical record) and with laboratory and pathological findings (eg, surgical, autopsy). The medical and imaging evidence, particularly when there is only central nervous system injury, cannot reliably diagnose intentional injury. Only the child protection investigation may provide the basis for inflicted injury in the context of supportive medical, imaging, biomechanical, or pathological findings.

Transient bacteraemia: A possible cause of sudden life threatening events

The concept proposed is that transient bacteraemia occurring in otherwise healthy individuals can cause acute life threatening events due to bacterial toxaemia even though the bacteraemia is rapidly cleared (<20 min). This is most likely to occur in infancy at around two to three months of age when anti-toxin IgG reaches its nadir. Sudden unexpected death in infancy, acute life threatening events, haemorrhagic shock and encephalopathy, and the triad of retinal haemorrhage, encephalopathy and bilateral thin film subdural haematomata are conditions which could be caused by this mechanism. Investigations need to be directed to measuring bacterial toxins in blood, CSF and urine; anti-toxin IgG in blood; and bacterial specific nucleic acid sequences in blood, CSF and urine using polymerase chain reaction in order to confirm recent bacteraemia. Furthermore the upper respiratory tract bacterial flora should be mapped in cases and appropriately matched live healthy community controls. Sudden onset, profound life threatening physiological dysfunction occurring in later life could also be caused by a similar mechanism and should be investigated in a similar way; candidate conditions include epilepsy, migraine, stroke and cardiac arrhythmias.

Shaken Baby Syndrome: An Odyssey

Shaken baby syndrome is evaluated in the context of its historical evolution and its veracity in referring to causal injury mechanisms. A rational assessment of the injury causation and consequent pathological states associated with the syndrome is presented. It is now evident that shaken baby syndrome evolved as a result of a faulty application of scientific reasoning and a lack of appreciation of mechanisms of injury. A brief explanation of the commonly understood usage and interface of scientific methodology and reasoning as applied to clinical medicine is given.

Case Analysis of Brain-Injured Admittedly Shaken Infants

The English-language medical case literature was searched for cases of apparent or alleged child abuse between the years 1969 and 2001. Three-hundred and twenty-four cases that contained detailed individual case information were analyzed yielding 54 cases in which someone was recorded as having admitted, in some fashion, to have shaken the injured baby. Individual case findings were tabulated and analyzed with respect to shaking as being the cause for the injuries reported. For all 54 admittedly-shaken-infant cases, the provided details regarding the shaking incidents and other events are reported. Data in the case reports varied widely with respect to important details. Only 11 cases of admittedly shaken babies showed no sign of cranial impact (apparently free-shaken). This small number of cases does not permit valid statistical analysis or support for many of the commonly stated aspects of the so-called shaken baby syndrome.