Case Analysis of Brain-Injured Admittedly Shaken Infants

Can Hemorrhagic Stroke Genetics Help Forensic Diagnosis in Pediatric Age (<5 Years Old)?

When stroke occurs in pediatric age, it might be mistakenly interpreted as non-accidental head injury (NAHI). In these situations, a multidisciplinary approach is fundamental, including a thorough personal and familial history, along with accurate physical examination and additional investigations. Especially when the clinical picture is uncertain, it is important to remember that certain genetic conditions can cause bleeding inside the brain, which may resemble NAHI. Pediatric strokes occurring around the time of birth can also be an initial sign of undiagnosed genetic disorders. Hence, it is crucial to conduct a thorough evaluation, including genetic testing, when there is a suspicion of NAHI but the symptoms are unclear. In these cases, a characteristic set of symptoms is often observed. This study aims to summarize some of the genetic causes of hemorrhagic stroke in the pediatric population, thus mimicking non-accidental head injury, considering elements that can be useful in characterizing pathologies. A systematic review of genetic disorders that may cause ICH in children was carried out according to the Preferred Reporting Item for Systematic Review (PRISMA) standards. We selected 10 articles regarding the main genetic diseases in stroke; we additionally selected 11 papers concerning patients with pediatric stroke and genetic diseases, or studies outlining the characteristics of stroke in these patients. The disorders we identified were Moyamoya disease (MMD), COL4A1, COL4A2 pathogenic variant, Ehlers-Danlos syndrome (E-D), neurofibromatosis type 1 (Nf1), sickle cell disease (SCD), cerebral cavernous malformations (CCM), hereditary hemorrhagic telangiectasia (HHT) and Marfan syndrome. In conclusion, this paper provides a comprehensive overview of the genetic disorders that could be tested in children when there is a suspicion of NAHI but an unclear picture.

Spinal cord injury as an indicator of abuse in forensic assessment of abusive head trauma (AHT)

Abusive head trauma (AHT) in children is notoriously one of the most challenging diagnoses for the forensic pathologist. The pathological “triad”, a combination of intracranial subdural haematoma, cerebral oedema with hypoxic-ischaemic changes and retinal haemorrhages, is frequently argued to be insufficient to support a corroborated verdict of abuse. Data from all available English-language scientific literature involving radiological and neuropathological spinal cord examination is reviewed here in order to assess the contribution of spinal cord changes in differentiating abusive from accidental head trauma. In agreement with the statistically proven association between spinal subdural haemorrhage (SDH) and abuse (Choudhary et al. in Radiology 262:216–223, 2012), spinal blood collection proved to be the most indicative finding related to abusive aetiology. The incidence of spinal blood collection is as much as 44–48% when all the spinal cord levels are analysed as opposed to just 0–18% when the assessment is performed at cervical level only, in agreement with the evidence of the most frequent spinal SDH location at thoracolumbar rather than cervical level. In this review, the source of spinal cord blood collection and how the age of the child relates to the position of spinal cord lesions is also discussed. We concluded that the ante mortem MRI examination and post mortem examination of whole-length spinal cord is of fundamental interest for the assessment of abuse in the forensic setting.

Abusive head trauma in court: a multi-center study on criminal proceedings in Germany

The shaken baby syndrome (SBS) is a common variant of abusive head trauma (AHT) in infants and toddlers. Data on the legal outcome of such cases are still sparse. By means of a retrospective multi-center analysis, 72 cases of living children diagnosed with SBS/AHT from three German university institutes of legal medicine were identified. Forty-six of these cases with 68 accused individuals were available and could be evaluated with regard to basic data on the course of the criminal proceedings as well as the profile of the defendants (sub-divided into suspects, convicts, and confessed perpetrators). Criminal proceedings predominantly commenced with a complaint by the treating hospital (62%) and were found to be closed (without judgment) in 50% of the cases, mostly due to a “lack of sufficient suspicion.” Of the 23 cases with judgment, the court decided on acquittal in 4 cases (17%). Imprisonment was the most frequent sentence (16 out of 19 cases with conviction, 84%), whereby the sentence has been suspended on probation in 63% of the cases. Suspects and perpetrators were mostly male and derived from the close family environment of the injured children. All confessed perpetrators stated an “excessive demand” as the reason for the violent shaking of the child. The results of the present study are in line with data from other studies with other legal systems. As many criminal proceedings were closed and the 4 acquittals occurred because the perpetration could not be ascribed to a specific perpetrator, improving the forensic methods for such an unequivocal assignment would be desirable.

Is there an association between infantile colic and subdural hemorrhage?

We present the hypothesis that subdural hemorrhages during childbirth might be associated with so-called three-month colic, whereby an infant cries intensively and repeatedly during its first three months. A traditional interpretation is that this infantile crying is associated with nutrition and is accordingly "a gut issue", but this is probably not the whole explanation. It has also been suggested that infantile crying can trigger a caregiver to shake the baby to make it stop crying, thereby inflicting a subdural hemorrhage. A mechanism-based argument supporting our hypothesis would be that the bilateral film-thin subdural hemorrhage associated with a high percentage of deliveries might cause meningeal irritation and in some cases also symptoms as inconsolable crying. An epidemiological argument is that infantile crying is more frequent among first-born, male and premature babies; these categories have also an increased incidence of subdural hemorrhage. Moreover, preventive programs for managing infantile crying have had no effect on the incidence of alleged shaken baby cases. As infantile crying is currently considered unexplained, it is reasonable to explore the proposed hypothesis and strategies which refute or corroborate it. We suggest that a cohort study of premature, first born and male babies with and without infantile crying are examined with brain MRI scan soon after delivery with clinically and MRI follow up during 3-6 months.

What Do Confessions Reveal About Abusive Head Trauma? A Systematic Review

Although confessions related to abusive head trauma (AHT) are reported, no detailed analysis exists. Therefore, we systematically reviewed studies of AHT confessions and examined the details, including country of origin, mechanisms and perpetrators' characteristics [PUBLISHER - THE PRECEDING UNDERLINED TEXT IS FOR THE MARGIN]. Employing 36 search terms across three search engines, we searched Medline and CINAHL from 1963 to 2018. All relevant studies underwent two independent reviews and data extraction. Descriptive statistics were used to characterise the sample; chi square and Fisher's exact tests were used to assess differences in demographic and clinical characteristics. Of 6759 identified studies, 157 full texts were reviewed and 55 articles from 15 countries spanning four continents were included. Included articles contained 434 confessions. The mechanisms of abuse included shaking alone (64.1%), impact alone (17.1%), shaking plus impact (18.0%) and other (0.9%). There was no statistically significant difference in the percentage of confessions reporting shaking alone when comparing continents: North America (64.0%), Europe (64.2%) and Oceania (60.0%; P=.92), or when comparing circumstances in which the confession was obtained: medical evaluation (74.6%) vs police or judicial investigations (63.4%; P=.11). Of 119 cases with identified perpetrators, 67.2 per cent were cases with males alone. Confessions reveal striking similarities in the mechanism of AHT (predominantly shaking) and occur across the globe.

Insufficient evidence for 'shaken baby syndrome' - a systematic review

Shaken baby syndrome has typically been associated with findings of subdural haematoma, retinal haemorrhages and encephalopathy, which are referred to as the triad. During the last decade, however, the certainty with which the triad can indicate that an infant has been violently shaken has been increasingly questioned. The aim of this study was to determine the diagnostic accuracy of the triad in detecting that an infant had been shaken. The literature search was performed using PubMed, Embase and the Cochrane Library up to October 15, 2015. Relevant publications were assessed for the risk of bias using the QUADAS tool and were classified as having a low, moderate or high risk of bias according to predefined criteria. The reference standards were confessions or witnessed cases of shaking or accidents. The search generated 3773 abstracts, 1064 were assessed as possibly relevant and read as full texts, and 30 studies were ultimately included. Of these, 28 were assessed as having a high risk of bias, which was associated with methodological shortcomings as well as circular reasoning when classifying shaken baby cases and controls. The two studies with a moderate risk of bias used confessions and convictions when classifying shaken baby cases, but their different designs made a meta-analysis impossible. None of the studies had a low risk of bias.

CONCLUSION

The systematic review indicates that there is insufficient scientific evidence on which to assess the diagnostic accuracy of the triad in identifying traumatic shaking (very low-quality evidence). It was also demonstrated that there is limited scientific evidence that the triad and therefore its components can be associated with traumatic shaking (low-quality evidence).

Forensic medical evaluations of child maltreatment: a proposed research agenda

Physicians play an important role in the forensic evaluation of suspected child abuse and neglect. There has been considerable progress in the medical field, helping distinguish findings related to maltreatment from other conditions or circumstances. Nevertheless, important questions remain. This article covers several of these questions and proposes a research agenda concerning five main topics: sexual abuse, neglect, fractures, abusive head trauma, and physicians work in interdisciplinary settings. The suggestions are hardly inclusive, but offer suggestions the authors think are priorities, and ones that research could reasonably address. By providing some background to gaps in our knowledge, this paper should be of interest to a broader audience than just medical professionals.

Fatal pediatric head injuries: a 20-year review of cases through the Auckland coroner's office

Inflicted pediatric head injury is a significant issue in New Zealand, fatal cases receiving extensive media attention. The primary aims of this article were to analyze injury patterns and reported mechanisms against both age and cause (accidental or inflicted). The secondary aims were to quantify these deaths and identify trends over time. We retrospectively reviewed pediatric deaths due to head injury in children younger than 15 years referred to the Coronial Service of Auckland, New Zealand, from January 1, 1991, to December 31, 2010. One hundred sixty-seven cases were identified. Overall incidence was stable over time; however, the rate of inflicted head injury increased significantly (from 0.1 to 0.4/100,000 per year). Evidence of impact was seen in 90% of cases. In children younger than 2 years, in the absence of motor vehicle or pedestrian trauma, subdural hemorrhage and diffuse axonal injury were both highly suggestive of inflicted injury. The absence of a history of trauma or a history of a fall less than 1 m was also highly suggestive of inflicted injury. Retinal hemorrhages in these fatal head injuries were severe in 77% of cases and moderate in the remainder.

Retinal hemorrhages in intubated pediatric intensive care patients

PURPOSE

To define the diagnoses associated with the presence of retinal hemorrhages, to clarify the association between retinal hemorrhages, cardiopulmonary resuscitation (CPR), and coagulopathy, and to describe the type of retinal hemorrhages found in intubated critically ill patients <4 years of age.

METHODS

This was a prospective observational study of intubated patients <4 years of age admitted to the pediatric intensive care unit of a tertiary care center from March 2010 to May 2012. The presence and description of retinal hemorrhages was recorded along with diagnoses, international normalized ratio (INR), CPR (in minutes), and mortality.

RESULTS

A total of 85 intubated, critically ill patients (37 females) were included; average patient age was 8.2 months (range, 0.1-46.8 months). Of the 85 patients, 6 (7%) had retinal hemorrhages (95% CI, 0.029-0.153). Of the 6 patients with RH, abusive head trauma (AHT) was diagnosed in 4 patients, 1 patient had direct head trauma, and 1 had CPR. There were 8 patients with CPR out of the 85. AHT was highly associated with severe multilayered retinal hemorrhages (P = 0.0001) but coagulopathy (P = 0.2671) and CPR (P = 0.5342) were not.

CONCLUSIONS

Severe multilayered retinal hemorrhages were associated with AHT in this cohort of patients. Without a history of trauma, retinal hemorrhages occurred in only 1 of 85 patients; in this case the hemorrhages were mild, confined to the posterior pole, and found only in the retinal layer.

Patterns of structural head injury in children younger than 3 years: a ten-year review of 519 patients

BACKGROUND

Abusive head injury is a major contributor to morbidity and mortality in infants and toddlers, but data comparing patterns of injury in corroborated accidental trauma and confessed child abuse are scarce.

METHODS

This is a retrospective review of head injuries with abnormal neuroimaging in children younger than 3 years during a 10-year period in Auckland, New Zealand. Histories were assumed to be true. Results were analyzed for incongruity then compared with data on confessed abuse and corroborated accidental injury.

RESULTS

Five hundred nineteen cases were analyzed. Most cases were congruent with the history, and their pattern was consistent with the literature on accidental head trauma in childhood. However, a spike of subdural hemorrhage was seen in the first 6 months of life, explained neither by mechanism nor by published data on birth trauma. The age distribution of retinal hemorrhage was also inconsistent with published data on birth trauma. In infants younger than 6 months, retinal and subdural hemorrhages were associated with the absence of a history of trauma. In older children (6 months-3 years), subdural hemorrhage was more common after minor falls (<1 m, 49%) than major falls (>2 m, 20%) (p = 0.002).

CONCLUSION

We conclude that when a young child (particularly an infant younger than 6 months) presents with traumatic intracranial pathology and either no history of trauma or a history of a minor fall, it must be seriously considered that the history is false.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

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.

The "Shaken Baby" syndrome: pathology and mechanisms

The "Shaken Baby" syndrome (SBS) is the subject of intense controversy; the diagnosis has in the past depended on the triad of subdural haemorrhage (SDH), retinal haemorrhage and encephalopathy. While there is no doubt that infants do suffer abusive injury at the hands of their carers and that impact can cause catastrophic intracranial damage, research has repeatedly undermined the hypothesis that shaking per se can cause this triad. The term non-accidental head injury has therefore been widely adopted. This review will focus on the pathology and mechanisms of the three physiologically associated findings which constitute the "triad" and are seen in infants suffering from a wide range of non-traumatic as well as traumatic conditions. "Sub" dural bleeding in fact originates within the deep layers of the dura. The potential sources of SDH include: the bridging veins, small vessels within the dura itself, a granulating haemorrhagic membrane and ruptured intracranial aneurysm. Most neuropathologists do not routinely examine eyes, but the significance of this second arm of the triad in the diagnosis of Shaken Baby syndrome is such that it merits consideration in the context of this review. While retinal haemorrhage can be seen clinically, dural and subarachnoid optic nerve sheath haemorrhage is usually seen exclusively by the pathologist and only rarely described by the neuroradiologist. The term encephalopathy is used loosely in the context of SBS. It may encompass anything from vomiting, irritability, feeding difficulties or floppiness to seizures, apnoea and fulminant brain swelling. The spectrum of brain pathology associated with retinal and subdural bleeding from a variety of causes is described. The most important cerebral pathology is swelling and hypoxic-ischaemic injury. Mechanical shearing injury is rare and contusions, the hallmark of adult traumatic brain damage, are vanishingly rare in infants under 1 year of age. Clefts and haemorrhages in the immediate subcortical white matter have been assumed to be due to trauma but factors specific to this age group offer other explanations. Finally, examples of the most common causes of the triad encountered in clinical diagnostic and forensic practice are briefly annotated.

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.

Abusive head trauma: A perpetrator confesses

OBJECTIVES

To present a detailed confession from a perpetrator of Shaken Baby syndrome.

METHODS

Case study.

RESULTS

We present a confession of Shaken Baby syndrome describing how the perpetrator severely injured a 3 year old with repeated bursts of acceleration-deceleration (shaking). The child sustained retinal and intracranial hemorrhage. Details of the confession and circumstances by which it was obtained lead us to believe its accuracy.

CONCLUSIONS

Accurate perpetrator confessions offer useful windows into realities and pathophysiology of abusive head trauma.

Abusive head trauma: judicial admissions highlight violent and repetitive shaking

OBJECTIVE

Confessions are uncommon in abusive head trauma (AHT) cases, and there is debate over whether shaking alone can cause the injuries characteristic of AHT. The objective of this article is to correlate legal statements by perpetrators with medical documentation to offer insights into the mechanism of injury.

METHODS

In this retrospective observational study we examined forensic evidence from 112 cases referred for AHT over a 7-year period. We compared 29 cases in which a perpetrator confessed to violence toward the child with 83 cases in which there was no confession. Inclusion criteria were subdural hematoma (SDH) on computed tomography and perpetrator admission of a causal relationship between the violence inflicted and the child's symptoms. Groups were compared by using Student's t test for age and Fisher's exact test for gender, death, fractures, retinal hemorrhages, ecchymoses, symptoms, and SDH patterns. All medical records from birth to diagnosis, imaging studies, and written investigation reports were reviewed.

RESULTS

All confessions came from forensic investigations. There was no statistically significant difference between the 2 groups for any of the variables studied. Shaking was described as extremely violent (100%) and was repeated (55%) from 2 to 30 times (mean: 10) because it stopped the infant's crying (62.5%). Impact was uncommon (24%). No correlation was found between repeated shaking and SDH densities.

CONCLUSIONS

This unique forensic case series confirms the violence of shaking. The high frequency of habitual AHT is a strong argument for reporting suspected cases to judicial authorities and helps to explain the difficulty in dating the injuries.

Confessed abuse versus witnessed accidents in infants: comparison of clinical, radiological, and ophthalmological data in corroborated cases

BACKGROUND

The diagnosis of inflicted head injury (IHI) or accidental trauma (AT) in infants is based on clinical, radiological, and/or ophthalmological findings such as subdural hematoma (SDH), encephalopathy, retinal hemorrhage (RH), and signs of impact. As a consequence, the diagnostic value of these criteria is difficult to assess because of a circularity bias.

PURPOSE

In order to assess the predictive value of these diagnostic criteria avoiding circularity, we studied prospectively corroborated cases of head injuries in infants, comparing IHI with AT.

MATERIAL AND METHODS

We selected 45 cases of confessed IHI and 39 cases of AT having occurred in public places. Patients were systematically evaluated clinically, with computed tomography scanner and ophthalmological evaluation by a trained ophthalmologist. RH was rated as absent, mild, and severe, according to the depth and extent of the RH.

RESULTS

Brain ischemia was found in 26.7% of IHI; the most prominent elements in favor of IHI were SDH, severe RH, and absence of signs of impact; the predictive diagnostic values of these three features were 0.685, 0.961, and 0.830, respectively; however, only severe RH in the absence of ocular impact was specific of IHI. When all three features were combined, the specificity was 100%, but the sensitivity was only 24.4%.

CONCLUSION

Our study confirms the high diagnostic value of RH, SDH, and signs of impact for the differential diagnosis between AT and IHI. The evaluation of head injuries in infants requires a high level of awareness and thorough and systematic examination by a trained multidisciplinary team.

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.

Retinal hemorrhages: advances in understanding

Retinal hemorrhage is a cardinal manifestation of abusive head injury characterized by repetitive acceleration-deceleration with or without blunt head impact. Detailed description of the hemorrhages and documentation are critical to diagnosis. Vitreoretinal traction appears to be the major causative factor. Outcome is largely dependent on brain and optic nerve injury.

Shaken baby syndrome: a common variant of non-accidental head injury in infants

BACKGROUND

Recent cases of child abuse reported in the media have underlined the importance of unambiguous diagnosis and appropriate action. Failure to recognize abuse may have severe consequences. Abuse of infants often leaves few external signs of injury and therefore merits special diligence, especially in the case of non-accidental head injury, which has high morbidity and mortality.

METHODS

Selective literature review including an overview over national and international recommendations.

RESULTS

Shaken baby syndrome is a common manifestation of non-accidental head injury in infancy. In Germany, there are an estimated 100 to 200 cases annually. The characteristic findings are diffuse encephalopathy and subdural and retinal hemorrhage in the absence of an adequate explanation. The mortality can be as high as 30%, and up to 70% of survivors suffer long-term impairment. Assessment of suspected child abuse requires meticulous documentation in order to preserve evidence as well as radiological, ophthalmological, laboratory, and forensic investigations.

CONCLUSIONS

The correct diagnosis of shaken baby syndrome requires understanding of the underlying pathophysiology. Assessment of suspected child abuse necessitates painstaking clinical examination with careful documentation of the findings. A multidisciplinary approach is indicated. Continuation, expansion, and evaluation of existing preventive measures in Germany is required.

Neck injuries in young pediatric homicide victims

OBJECT

In this study, the authors estimate the prevalence of injuries to the soft tissue of the neck, cervical vertebrae, and cervical spinal cord among victims of abusive head trauma to better understand these injuries and their relationship to other pathophysiological findings commonly found in children with fatal abusive head trauma.

METHODS

The population included all homicide victims 2 years of age and younger from the city of Philadelphia, Pennyslvania, who underwent a comprehensive postmortem examination at the Office of the Medical Examiner between 1995 and 2003. A retrospective review of all available postmortem records was performed, and data regarding numerous pathological findings, as well as the patient's clinical history and demographic information, were abstracted. Data were described using means and standard deviations for continuous variables, and frequency and ranges for categorical variables. Chi-square analyses were used to test for the association of neck injuries with different types of brain injury.

RESULTS

The sample included 52 children, 41 (79%) of whom died of abusive head trauma. Of these, 29 (71%) had primary cervical cord injuries: in 21 there were parenchymal injuries, in 24 meningeal hemorrhages, and in 16, nerve root avulsion/dorsal root ganglion hemorrhage were evident. Six children with abusive head trauma had no evidence of an impact to the head, and all 6 had primary cervical spinal cord injury (SCI). No child had a spinal fracture. Six of 29 children (21%) with primary cervical SCIs had soft-tissue (ligamentous or muscular) injuries to the neck, and 14 (48%) had brainstem injuries. There was a significant association of primary cervical SCI with cerebral edema (p = 0.036) but not with hypoxia-ischemia, infarction, or herniation.

CONCLUSIONS

Cervical SCI is a frequent but not universal finding in young children with fatal abusive head trauma. In the present study, parenchymal and/or root injury usually occurred without evidence of muscular or ligamentous damage, or of bone dislocation or fracture. Moreover, associated brainstem injuries were not always seen. Although there was a significant association of primary cervical cord injury with cerebral edema, there was no direct relationship to brainstem herniation, hypoxia-ischemia, or infarction. This suggests that cervical spinal trauma is only 1 factor in the pathogenesis of these lesions.

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: 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.

Delayed homicides due to infant head injury initially reported as natural (cerebral palsy) deaths

A spectrum of neuropathology occurs in infants who sustain traumatic brain injury. Because of a prolonged survival interval, there is a risk that these deaths may not be recognized as a sequel of trauma. We reviewed the records in New York City of 5 delayed fatalities due to nonaccidental infant head injury that had survival intervals from 2.5 to 17 years. The head injuries occurred at 2 to 3 months of age, and death occurred at 2.5 to 17 years of age. Initially, they were reported as natural deaths by treating physicians, families, and/or police. All 5 infants had unexplained or poorly explained remote traumatic head injury that included subdural hematomas. At autopsy, the neuropathologic exam demonstrated remote subdural hemorrhages and lesions related to chronic hypoxic-ischemic injury including atrophy, arterial infarcts, border-zone infarcts, and cystic encephalomalacia. Each child survived the initial injury but later succumbed to the delayed effects of secondary hypoxic-ischemic encephalopathy. These 5 deaths highlight the need to investigate independently the medical history of any child (or adult) who dies with a clinical diagnosis of "cerebral palsy." The term cerebral palsy often is used as a catchall for any patient who has had neurologic impairment since infancy or childhood. If there is a direct link between the initial injury and the death, even if the injury occurred many years before death, then the injury is the proximate cause of death and dictates the manner of death. All 5 deaths were certified as homicides.

Lack of evidence for a causal relationship between hypoxic-ischemic encephalopathy and subdural hemorrhage in fetal life, infancy, and early childhood

It has been asserted that hypoxic-ischemic encephalopathy (HIE) with cerebral swelling in the absence of marked trauma may be responsible for subural hemorrhage in the young. As this may have considerable implications in determining both the mechanism of death and the degree of force required to cause injury in certain cases of inflicted head injury in infancy, clarification is required. A retrospective study of 82 fetuses, infants, and toddlers with proven HIE and no trauma was undertaken from forensic institutes in Australia, the United Kingdom, Germany, Denmark, and the United States. The age range was 35 weeks gestation to 3 years, with a male to female ratio of 2:1. All cases had histologically confirmed HIE. Causes of the hypoxic episodes were temporarily resuscitated sudden infant death syndrome with delayed death (N = 30), drowning (N = 12), accidental asphyxia (N = 10), intrauterine/delivery asphyxia (N = 8), congenital disease (N = 6), aspiration of food/gastric contents (N = 4), inflicted asphyxia (N = 3), epilepsy (N = 1), dehydration (N = 1), drug toxicity (N = 1), complications of prematurity (N = 1), and complications of anesthesia (N = 1). The initiating event was not determined in 4 instances. In no case was there macroscopic evidence of subdural hemorrhage. In this study no support could be given to the hypothesis that HIE in the young in the absence of trauma causes subdural hemorrhage.

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.

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.

Forensic aspects related to pediatric pathology--Medicolegal aspects of pediatric head injuries

The pathological examination and assessment of inflicted head injuries in infants and young children are often complicated by the subtle nature of the injuries, the non-specificity of lesions, and the lack of experimental data that can be used to clarify possible forces and mechanisms of damage. Opinions often have to be given on a number of issues, with a paucity of information in the literature and lack of specific individual experience. The following paper reviews some of the problems that are currently found in the medicolegal evaluation of infants and young children with inflicted craniocerebral trauma and issues that consequently arise in court.

Paroxysmal coughing, subdural and retinal bleeding: a computer modelling approach

Unexplained subdural and retinal haemorrhages in an infant are commonly attributed to 'shaking', the mechanism of which is believed to be traumatic venous rupture. However, the haemorrhagic retinopathy reported as a result of Valsalva manoeuvres and the subdural bleeding that is a rare complication of pertussis together demonstrate that if a sustained rise in intrathoracic pressure is transmitted to cerebral and retinal vessels, it may result in bleeding, similar to that reported in inflicted injury. Such haemorrhages would be expected to occur whenever severe paroxysmal coughing were induced, whatever the cause. This study used a computer modelling approach to investigate feeding accidents as the trigger for bleeding. A dynamic circulatory model of a 3-month-old infant was induced to 'cough', and the response to changes in physiological variables monitored. It showed that coughing causes intracranial pressures to build up exponentially to approach a maximum, proportional to the amount of pressure the musculature of the thorax can produce, as venous return is impeded. They do not have time to become dangerous during individual coughs, as blood quickly returns after the cough is over, reestablishing normal pressures. Paroxysmal coughing, however, does not allow blood to return between coughs, with the result that very high luminal pressures may be generated, sufficient to damage veins. A history of coughing, vomiting or choking is not uncommon in otherwise normal infants with retinal and subdural bleeding. Our findings suggest that paroxysmal coughing could account for such bleeding in some cases.

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.