The "Shaken Baby" syndrome: pathology and mechanisms

Neuroimaging of Neonatal Stroke: Venous Focus

Perinatal venous infarcts are underrecognized clinically and at imaging. Neonates may be susceptible to venous infarcts because of hypercoagulable state, compressibility of the dural sinuses and superficial veins due to patent sutures, immature cerebral venous drainage pathways, and drastic physiologic changes of the brain circulation in the perinatal period. About 43% of cases of pediatric cerebral sinovenous thrombosis occur in the neonatal period. Venous infarcts can be recognized by ischemia or hemorrhage that does not respect an arterial territory. Knowledge of venous drainage pathways and territories can help radiologists recognize characteristic venous infarct patterns. Intraventricular hemorrhage in a term neonate with thalamocaudate hemorrhage should raise concern for internal cerebral vein thrombosis. A striato-hippocampal pattern of hemorrhage indicates basal vein of Rosenthal thrombosis. Choroid plexus hemorrhage may be due to obstruction of choroidal veins that drain the internal cerebral vein or basal vein of Rosenthal. Fan-shaped deep medullary venous congestion or thrombosis is due to impaired venous drainage into the subependymal veins, most commonly caused by germinal matrix hemorrhage in the premature infant and impeded flow in the deep venous system in the term infant. Subpial hemorrhage, an underrecognized hemorrhage stroke type, is often observed in the superficial temporal region, and its cause is probably multifactorial. The treatment of cerebral sinovenous thrombosis is anticoagulation, which should be considered even in the presence of intracranial hemorrhage. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

New Insights into the Diagnosis and Age Determination of Retinal Hemorrhages from Abusive Head Trauma: A Systematic Review

(1) Background: Head trauma represents the first cause of death in abused children, but diagnostic knowledge is still limited. The characteristic findings of abusive head trauma (AHT) are retinal hemorrhages (RH) and additional ocular findings, including optic nerve hemorrhages (ONH). However, etiological diagnosis must be cautious. (2) Methods: The Preferred Reporting Items for Systematic Review (PRISMA) standards were employed, and the research focus was the current gold standard in the diagnosis and timing of abusive RH. (3) Results: Sixteen articles were included for qualitative synthesis. The importance of an early instrumental ophthalmological assessment emerged in subjects with a high suspicion of AHT, with attention to the localization, laterality, and morphology of the findings. Sometimes it is possible to observe the fundus even in deceased subjects, but the current techniques of choice consist of Magnetic Resonance Imaging and Computed Tomography, also useful for the timing of the lesion, the autopsy, and the histological investigation, especially if performed with the use of immunohistochemical reactants against erythrocytes, leukocytes, and ischemic nerve cells. (4) Conclusions: The present review has made it possible to build an operational framework for the diagnosis and timing of cases of abusive retinal damage, but further research in the field is needed.

The eye in child abuse

Child physical abuse may result in a range of injuries to the globe and surrounding tissues. These injuries have varying degrees of specificity for abuse, and no pattern of injury is unique to abuse. Easily overlooked eye injuries in non-ambulatory infants often portend more severe abuse and require careful evaluation for occult injury when they are unexplained. Retinal hemorrhages are most often a sign of significant trauma and the severity of the hemorrhages generally parallels the severity of neurological trauma. Ophthalmologists contribute important data that more easily distinguish medical disease from trauma, but caution is needed in differentiating accidental from inflicted trauma. This distinction requires careful consideration of the complete clinical data and occasionally on additional law enforcement or child welfare investigation.

Cerebral hemorrhage caused by shaking adult syndrome? Evidence from biomechanical analysis using 3D motion capture and finite element models

The present study combined three-dimensional (3D) motion capture with finite element simulation to reconstruct a real shaking adult syndrome (SAS) case and further explore the injury biomechanics of SAS. The frequency at which an adult male can shake the head of another person, head-shaking amplitude, and displacement curves was captured by the VICON 3D motion capture system. The captured shaking frequency and shaking curve were loaded on the total human model for safety (THUMS) head to simulate the biomechanical response of brain injury when a head was shaken in anterior-posterior, left-right, and left anterior-right posterior directions at frequencies of 4 Hz (Hz), 5 Hz, 6 Hz, and 7 Hz. The biomechanical response of the head on impact in the anterior, posterior, left, left anterior, and right posterior directions at the equivalent velocity of 6 Hz shaking was simulated. The violent shaking frequency of the adult male was 3.2-6.8 Hz; head shaking at these frequencies could result in serious cerebral injuries. SAS-related injuries have obvious directionality, and sagittal shaking can easily cause brain injuries. There was no significant difference between the brain injuries caused by shaking in the simulated frequency range (4-7 Hz). Impact and shaking at an equivalent velocity could cause brain injuries, though SAS more commonly occurred due to the cumulative deformation of brain tissue. Biomechanical studies of SAS should play a positive role in improving the accuracy of forensic identification and reducing this form of abuse and torture in detention or places of imprisonment.

Factor XIII deficiency in a neonate presenting as subpial haemorrhage

Subpial haemorrhage is a rare cause of seizures in term neonates. A 3-day-old male infant, born at term with no history of perinatal hypoxia, presented with seizures and unremarkable physical examination in the interictal state. Imaging demonstrated left temporal subpial haemorrhage with the classic ‘yin-yang sign’ on MRI. The patient was subsequently diagnosed with factor XIII deficiency. Follow-up at 6 months and 12 months revealed encephalomalacia in the previous haemorrhagic areas with normal developmental milestones.

Pitfalls in the interpretation of pediatric head CTs: what the emergency radiologist needs to know

Pediatric radiology studies can be some of the most anxiety-inducing imaging examinations encountered in practice. This can be in part due to the wide range of normal anatomic appearances inherent to the pediatric population that create potential interpretive pitfalls for radiologists. The pediatric head is no exception; for instance, the inherent greater water content within the neonatal brain compared to older patients could easily be mistaken for cerebral edema, and anatomic variant calvarial sutures can be mistaken for skull fractures. This article reviews potential pitfalls emergency radiologists may encounter in practice when interpreting pediatric head CTs, including trauma, extra-axial fluid collections, intra-axial hemorrhage, and ventriculoperitoneal shunt complications.

Transfer of knowledge to diagnose infant abuse and its incidence - a time-series analysis from Sweden

Aim

To analyse the transfer of knowledge on how to detect physical abuse, especially shaken baby syndrome/abusive head trauma (SBS/AHT), and its association to trends in infant abuse diagnoses (maltreatment and assault).

Methods

Design: retrospective population-based and quasi-experimental. Setting: Sweden 1987–2019. Patients: Children below age 1 year, selected from the National Patient Register (n = 1150). Exposures: Literature search for transfer of knowledge by diffusion, dissemination and implementation, and whether supportive or disruptive of the SBS/AHT paradigm. Main outcome measure: Abuse diagnoses (maltreatment or assault). Analyses: Incidence rate, incidence rate ratio (IRR).

Results

The overall incidence rate of abuse was 32.23 per 100,000 during the years 1987–2019. It was rather stable 1987–2000. The SBS diagnosis was introduced in the late 1990s. A comprehensive increase of transfer of knowledge on physical abuse, specifically on SBS/AHT and dangers of shaking, took place from 2002 and onward through diffusion, dissemination and implementation. Maltreatment diagnoses, but not assault diagnosis, increased steeply during 2002–2007, peaking in 2008–2013 [IRR 1.63 (95% confidence interval 1.34–1.98)]. Transfer of disruptive knowledge on SBS/AHT during the period 2014–2019 was associated with a decline in maltreatment diagnoses [IRR 0.84 (95% confidence interval 0.71–0.99)].

Conclusion

An increase in maltreatment diagnoses was associated with transfer of supportive knowledge of the SBS/AHT paradigm, while a decline occurred toward the end of the study period, which might indicate a burgeoning de-implementation process.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13012-022-01188-6.

Chronic subdural hemorrhage predisposes to development of cerebral venous thrombosis and associated retinal hemorrhages and subdural rebleeds in infants

For infants presenting with subdural hemorrhage, retinal hemorrhage, and neurological decline the "consensus" opinion is that this constellation represents child abuse and that cerebral venous sinus thrombosis and cortical vein thrombosis is a false mimic. This article contends that this conclusion is false for a subset of infants with no evidence of spinal, external head, or body injury and is the result of a poor radiologic evidence base and misinterpreted data. Underdiagnosis of thrombosis is the result of rapid clot dissolution and radiologic under recognition. A pre-existing/chronic subdural hemorrhage predisposes to development of venous sinus thrombosis/cortical vein thrombosis, triggered by minor trauma or an acute life-threatening event such as dysphagic choking, variably leading to retinal and subdural hemorrhages and neurologic decline. These conclusions are based on analysis of the neuroradiologic imaging findings in 11 infants, all featuring undiagnosed cortical vein or venous sinus thrombosis. Subtle neuroradiologic signs of and the mechanisms of thrombosis are discussed. Subarachnoid hemorrhage from leaking thrombosed cortical veins may be confused with acute subdural hemorrhage and probably contributes to the development of retinal hemorrhage ala Terson's syndrome. Chronic subdural hemorrhage rebleeding from minor trauma likely occurs more readily than bleeding from traumatic bridging vein rupture. Radiologists must meet the challenge of stringent evaluation of neuro imaging studies; any infant with a pre-existing subdural hemorrhage presenting with neurologic decline must be assumed to have venous sinus or cortical vein thrombosis until proven otherwise.

Pediatric skull fractures: could suture contact be a sign of abuse?

PURPOSE

Skull fractures in infants and young children can occur as a result of both accidental trauma and abuse. 1/3 of children with abuse-related head trauma and 1/5 of children with abuse-related fractures were overlooked during the initial evaluation. In this study, we aim to investigate the prevalence of skull fractures that come into contact with the suture in head traumas caused by accidents and abuse, and also to see if contact of the fracture line with the suture could be used as a sign for abuse in the pediatric population.

METHODS

Forry-four patients with head trauma were retrospectively assessed between January 2010 and June 2020 and were confirmed to have fractures on a brain CT. Patient age, gender, and head injury type were recorded. The fracture site, location and number, the contact of the fracture line with the suture, the name, and number of the suture it came into contact with were determined.

RESULTS

Twenty-eight skull fractures in 22 children with a diagnosis of child abuse and 25 skull fractures in 22 children due to accidental trauma were evaluated in the same age and gender range. Eighteen (64%) of 28 abuse-related skull fractures were in contact with two or more sutures. Two (8%) of 25 accident-related fractures were related to two or more sutures. Abuse-related fractures had a significantly higher suture contact rate than accident-related fractures (p = 0.007).

CONCLUSION

Contact with two or more sutures of a skull fracture is a finding related to abuse rather than accident.

Trends in shaken baby syndrome diagnosis codes among young children hospitalized for abuse

Objective

To investigate national trends of SBS diagnosis codes and how trends varied among patient and hospital characteristics.

Methods

We examined possible SBS, confirmed SBS, and non-SBS abuse diagnosis codes among children age three and younger who were hospitalized for abuse between 1998 and 2014 using a secondary analysis of the National Inpatient Sample, the largest US all-payer inpatient care database (N = 66,854). A baseline category logit model was used based on a quasi-likelihood approach (QIC) with an independent working correlation structure.

Results

The rate (per 100,000 census population of children age 3 and younger) of confirmed and possible SBS diagnosis codes was 5.4 (± 0.3) between 1998 and 2014, whereas the rate of non-SBS abuse was 19.6 (± 1.0). The rate of confirmed SBS diagnosis codes increased from 3.8 (± 0.3) in 1998 to 5.1 (± 0.9) in 2005, and decreased to 1.3 (± 0.2) in 2014. Possible SBS diagnosis codes were 0.6 (± 0.2) in 1998, increasing to 2.4 (± 0.4) in 2014. Confirmed SBS diagnosis codes have declined since 2002, while possible SBS diagnosis codes have increased. All abuse types were more frequent among infants, males, children from low-income homes, and urban teaching hospitals.

Conclusions

We investigated seventeen-year trends of SBS diagnosis codes among young children hospitalized for abuse. The discrepancy between trends in possible and confirmed SBS diagnosis codes suggests differences in norms for utilizing SBS diagnosis codes, which has implications for which hospital admissions are coded as AHT. Future research should investigate processes for using SBS diagnosis codes and whether all codes associated with abusive head injuries in young children are classified as AHT. Our findings also highlight the relativity defining and applying SBS diagnosis codes to children admitted to the hospital for shaking injuries. Medical professionals find utility in using SBS diagnosis codes, though may be more apt to apply codes related to possible SBS diagnosis codes in children presenting with abusive head injuries. Clarifying norms for SBS diagnosis codes and refining definitions for AHT diagnosis will ensure that young children presenting with, and coded for, abusive head injuries are included in overall counts of AHT based on secondary data of diagnosis codes. This baseline data, an essential component of child abuse surveillance, will enable ongoing efforts to track, prevent, and reduce child abuse.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40621-021-00334-w.

Deep medullary vein engorgement and superficial medullary vein engorgement: two patterns of perinatal venous stroke

Perinatal venous stroke has classically been attributed to cerebral sinovenous thrombosis with resultant congestion or thrombosis of the small veins draining the cerebrum. Advances in brain MRI, in particular susceptibility-weighted imaging, have enabled the visualization of the engorged small intracerebral veins, and the spectrum of perinatal venous stroke has expanded to include isolated congestion or thrombosis of the deep medullary veins and the superficial intracerebral veins. Congestion or thrombosis of the deep medullary veins or the superficial intracerebral veins can result in vasogenic edema, cytotoxic edema or hemorrhage in the territory of disrupted venous flow. Deep medullary vein engorgement and superficial medullary vein engorgement have characteristic findings on MRI and should be differentiated from neonatal hemorrhagic stroke.

Clinical evaluation and management of children with suspected physical abuse

Evaluating and managing children with suspected physical abuse is challenging. Few single injuries are pathognomonic for abuse and, as a result, child abuse is easily missed. As such, a healthy bit of skepticism is needed to recognize and protect abused children. The medical history and clinical presentation should guide evaluation. Medical providers must consider the differential diagnosis, epidemiology of injuries, and child development to inform the assessment. In this review, we address evidence-based recommendations to inform child physical abuse evaluations. We also discuss the role of medical providers in communicating with families, mandated reporting and interpreting medical information for investigative agencies and other non-medical colleagues entrusted with protecting children.

Pediatric Abusive Head Trauma: A Systematic Review

Abusive head trauma (AHT) represents a commonly misdiagnosed condition. In fact, there is no pathognomonic sign that allows the diagnosis in children. Therefore, it is such an important medico-legal challenge to evaluate reliable diagnostic tools. The aim of this review is to evaluate the current scientific evidence to assess what the best practice is in order to diagnose AHT. We have focused particularly on evaluating the importance of circumstantial evidence, clinical history, the use of postmortem radiological examinations (such as CT and MRI), and the performance of the autopsy. After autopsy, histological examination of the eye and brain play an important role, with attention paid to correlation with symptoms found in vivo.

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.

Shaken Baby Syndrome: Magnetic Resonance Imaging Features in Abusive Head Trauma

In the context of child abuse spectrum, abusive head trauma (AHT) represents the leading cause of fatal head injuries in children less than 2 years of age. Immature brain is characterized by high water content, partially myelinated neurons, and prominent subarachnoid space, thus being susceptible of devastating damage as consequence of acceleration–deceleration and rotational forces developed by violent shaking mechanism. Diagnosis of AHT is not straightforward and represents a medical, forensic, and social challenge, based on a multidisciplinary approach. Beside a detailed anamnesis, neuroimaging is essential to identify signs suggestive of AHT, often in absence of external detectable lesions. Magnetic resonance imaging (MRI) represents the radiation-free modality of choice to investigate the most typical findings in AHT, such as subdural hematoma, retinal hemorrhage, and hypoxic-ischemic damage and it also allows to detect more subtle signs as parenchymal lacerations, cranio-cervical junction, and spinal injuries. This paper is intended to review the main MRI findings of AHT in the central nervous system of infants, with a specific focus on both hemorrhagic and non-hemorrhagic injuries caused by the pathological mechanisms of shaking. Furthermore, this review provides a brief overview about the most appropriate and feasible MRI protocol to help neuroradiologists identifying AHT in clinical practice.

Chronic Subdural Hematoma (cSDH): A review of the current state of the art

Introduction

Incidence of Chronic Subdural Hematoma (cSDH) is rising worldwide, partly due to an aging population, but also due to increased use of antithrombotic medication. Many recent studies have emerged to address current cSDH management strategies.

Research question

What is the state of the art of cSDH management.

Material and methods

Review.

Results

Head trauma, antithrombotic use and craniocerebral disproportion increase the risk of cSDH development. Most patients present with disorientation, GCS 13–15, and symptoms arising from cortical irritation and increased intracranial pressure. cSDH occurs bilaterally in 9–22%. CT allows assessment of cerebral compression (herniation, hematoma thickness, ventricle collapse, midline shift), hematoma age and presence of membranes, factors that ultimately determine treatment urgency and surgical approach. Recurrence remains the principle complication (9–33%), occurring more commonly with older age and bilateral cSDHs.

Discussion and conclusion

While incompletely understood, it is generally believed that injury in the dural cell layer results in bleeding from bridging veins, resulting in a hematoma formation, with or without a preceding hygroma, in a potential space approximating the junction between the dura and arachnoid. Neovascularization and leaking from the outer membrane are thought to propagate this process. Evidence that MMA embolization may reduce recurrence rates is a potentially exciting new treatment option, but also supports the theory that the MMA is implicated in the cSDH pathophysiology. The use of steroids remains a controversial topic without clear treatment guidelines. cSDH represents a common neurosurgical problem with burr-hole treatment remaining the gold standard, often in conjunction with subgaleal drains. MMA embolization to stop recurrence may represent an important evolution in understanding the pathophysiology of cSDH and improving treatment.

•

Incidence of cSDH is rising, partly due to the aging population and increased antithrombotic use.

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cSDH occurs bilaterally in 9–22% of cases.

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Recurrence remains the principle complication and has been estimated at 9–33%.

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Risk factors for recurrence include old age and bilateral cSDHs.

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MMA embolization may reduce recurrence, but its efficacy and target population remain unclear.

Understanding Abusive Head Trauma: A Primer for the General Pediatrician

Abusive head trauma (AHT) refers to a well-recognized constellation of injuries caused by the direct application of force to an infant or young child, resulting in trauma to the head, intracranial contents, and/or neck, with potentially devastating health outcomes. Mechanisms of AHT include impulsive injurious acts, such as violent shaking and impact, often due to caregiver frustration or exhaustion. Subdural and retinal hemorrhage, and associated extracranial injury (fractures, abdominal trauma), are common. Suspected victims require laboratory/diagnostic testing and occult injury screening, as well as protective measures by investigative authorities to ensure safety. Medicolegal controversies persist around AHT diagnosis, including alternative hypotheses proffered in court by skeptics despite advances in scientific understanding, biomechanical research, neuroimaging techniques, and perpetrator confessions. Pediatricians play a key role in prevention and reduction of AHT morbidity and mortality through anticipatory guidance and caregiver education about the risks of shaking, normal infant development and behavior, and encouragement of stress reduction strategies. [Pediatr Ann. 2020;49(8):e347-e353.].

Neonatal shaking brain injury changes psychological stress-induced neuronal activity in adult male rats

Neonatal shaking brain injury (SBI) leads to increases in anxiety-like behavior and altered hormonal responses to psychological stressors as adults. These abnormalities are hypothesized to be due to a change in sensitization in neuronal circuits as a consequence of neonatal SBI. We examined the effects of neonatal SBI on neuronal activity in the anxiety- and/or stress-related areas of adult rats using Fos immunohistochemistry. Exposure to a novel elevated plus maze (EPM) resulted in a marked increase in Fos expression in the parvocellular (PVNp) and magnocellular parts of the paraventricular nucleus and the ventral part of the bed nucleus of the stria terminalis (vBNST) of shaken rats (S group) compared to non-shaken control rats (C group). On the contrary, Fos expression was significantly lower in the medial nucleus of the amygdala and the ventral subiculum (vS) of S group rats than C group rats exposed to EPM. Although we found no significant correlation in the number of Fos-expressing cells in the vBNST and PVNp in the C group rats, these numbers were significantly correlated in the S group rats. Furthermore, in the S group rats, but not in the C group rats, the number of Fos-expressing cells in the vBNST was inversely correlated with that in the vS. Interestingly, previous neuronal tracing studies have demonstrated direct projections from the vS to the vBNST and from the vBNST to the PVNp. The present data suggest that neonatal SBI can alter neuronal activity in anxiety- and/or stress-related neuronal circuits.

MRI Findings in Pediatric Abusive Head Trauma: A Review

Trauma is the most common cause of death and significant morbidity in childhood; abusive head trauma (AHT) is a prominent cause of significant morbidity and mortality in children younger than 2 years old. Correctly diagnosing AHT is challenging both clinically and radiologically. The primary diagnostic challenges are that the abused children are usually too young to provide an adequate history, perpetrators are unlikely to provide truthful account of trauma, and clinicians may be biased in their assessment of potentially abused children. The main radiological challenge is that there is no single imaging finding that is independently specific for or diagnostic of AHT. The radiological evaluation should be based on the multiplicity and severity of findings and an inconsistency with the provided mechanism of trauma. While the most common neuroimaging finding in AHT is subdural hemorrhage, other less well-known magnetic resonance imaging (MRI) findings such as the "lollipop sign" or "tadpole sign," parenchymal or cortical lacerations, subpial hemorrhage, cranio-cervical junction injuries including retroclival hematomas, as well as diffuse hypoxic brain injury have been identified and described in the recent literature. While AHT is ultimately a clinical diagnosis combining history, exam, and neuroimaging, familiarity with the typical as well as the less-well known MRI findings will improve recognition of AHT by radiologists.

The "New Science" of Abusive Head Trauma

Claims that new science is changing accepted medical opinion about abusive head injury have been made frequently in the media, legal publications and in legal cases involving abusive head trauma (AHT). This review analyzes recently published scientific articles about AHT to determine whether this new information has led to significant changes in the understanding, evaluation and management of children with suspected AHT. Several specific topics are examined: serious or fatal injuries from short falls; specificity of subdural hematoma for severe trauma; biomechanical explanations for findings; the specificity of retinal hemorrhages; the possibility of cerebral sinus thrombosis presenting with signs similar to AHT; and whether vaccines can produce such findings. We conclude: a) that the overwhelming weight of recent data does not change the fundamental consensus b) that abusive head trauma is a significant source of morbidity and mortality in children c) that subdural hematomas and severe retinal hemorrhages are commonly the result of severe trauma d) that these injuries should prompt an evaluation for abuse when identified in young children without a history of such severe trauma and e) that short falls, cerebral sinus thrombosis and vaccinations are not plausible explanations for findings that raise concern for abusive head trauma.

Cerebellar lesions in pediatric abusive head trauma

Pediatric abusive head trauma (AHT) or non accidental head trauma (NAHT) is a major cause of death from trauma in children under 2 years of age. Main etiological factor for non accidental head trauma is shaking a baby, causing brain injury by rotational head acceleration and deceleration. The consequent brain damage as shown by magnetic resonance imaging (MRI) is subdural haemorrhage and to a lesser extent parenchymal injuries of variable severity. Involvement of the cerebellum has very rarely been described. We report the clinical history and the development of cerebral magnetic resonance imaging findings in two children with serious brain injury following probable shaking who presented the typical "triad" with subdural haematoma, retinal haemorrhage and encephalopathy. We want to draw attention to cerebellar involvement characterized by cortico-subcortical signal alterations most prominent on T2w images following diffusion changes during the acute period. We discuss cerebellar involvement as a sign of higher severity of AHT which is probably underrecognized.

Evaluation of a Temporal Association between Vaccination and Subdural Hematoma in Infants

OBJECTIVE

To investigate a temporal association between vaccination and subdural hematoma, the main feature of abusive head trauma.

STUDY DESIGN

From a prospective population-based survey carried out in 1 administrative district in France between January 2015 and April 2017, including all infants between 11 and 52 weeks old who underwent a first cerebral imaging (computerized tomography scan or magnetic resonance imaging), we conducted a nested case-control study. Vaccine exposure was compared between cases (infants with subdural hematoma) and 2-3 paired controls, without subdural hematoma or any other imaging findings compatible with abusive head trauma. Cases and controls were matched on chronological (±7 days) and gestational (≤33 vs >33 weeks) ages, respectively. Vaccination status was collected in the personal national pediatric health booklet.

RESULTS

Among the 228 prospectively surveyed infants, 28 had subdural hematoma including 22 with abusive head trauma. The mean chronological age at imaging was 5.3 months among the 28 cases and the 62 controls, who did not differ significantly in median time since last vaccination (1.4 vs 1.3 months, P = .62) or frequency of at least 1 vaccination since birth (86% vs 89%; matched-pairs OR 0.77, 95% CI 0.17-3.86) or within 7 days (0.94, 0.08-6.96), 14 days (0.70, 0.12-2.92), or 21 days (0.48, 0.08-1.98) before cerebral imaging.

CONCLUSIONS

We found no significant temporal association between vaccination and subdural hematoma diagnosis, which must continue to be considered a red flag for abusive head trauma and child abuse.

Ocular and Intracranial MR Imaging Findings in Abusive Head Trauma

Abusive head trauma (AHT) is a form of inflicted head injury. AHT is more frequent in 2-year-old or younger children. It is an important cause of neurological impairment and the major cause of death from head trauma in this age group. Brain magnetic resonance imaging allows the depiction of retinal hemorrhages, injured bridging veins, and identifying and localizing extra- and intra-axial bleeds, contusions, lacerations, and strokes. The diagnosis of AHT is a multidisciplinary team effort which includes a careful evaluation of social, clinical, laboratory, and radiological findings. Notwithstanding, the introduction in the current clinical practice of high-resolution techniques is adding forensic evidence to the recognition of AHT.

Traumatic shaking: The role of the triad in medical investigations of suspected traumatic shaking

The Swedish Agency for Health Technology Assessment and Assesment of Social Services (SBU) is an independent national authority, tasked by the government with assessing methods used in health, medical and dental services and social service interventions from a broad perspective, covering medical, economic, ethical and social aspects. The language in SBU's reports are adjusted to a wide audience. SBU's Board of Directors has approved the conclusions in this report. The systematic review showed the following graded results: There is limited scientific evidence that the triad (Three components of a whole. The triad associated with SBS usually comprises subdural haematoma, retinal haemorrhages and encephalopathy.) and therefore, its components can be associated with traumatic shaking (low-quality evidence). There is insufficient scientific evidence on which to assess the diagnostic accuracy of the triad in identifying traumatic shaking (very low-quality evidence). Limited scientific evidence (low-quality evidence) represents a combined assessment of studies of high or moderate quality which disclose factors that markedly weaken the evidence. It is important to note that limited scientific evidence for the reliability of a method or an effect does not imply complete lack of scientific support. Insufficient scientific evidence (very low-quality evidence) represents either a lack of studies or situations when available studies are of low quality or show contradictory results. Evaluation of the evidence was not based on formal grading of the evidence according to GRADE but on an evaluation of the total scientific basis.

Prevalence, Patterns, and Clinical Relevance of Hypoxic-Ischemic Injuries in Children Exposed to Abusive Head Trauma

BACKGROUND AND PURPOSE

Hypoxic-ischemic injuries (HIIs) are a scarcely investigated but important cause of morbidity and mortality in children who suffered abusive head trauma (AHT). The purpose of this study is to determine: (a) prevalence, types, and clinical relevance of cytotoxic edema compatible with HII in nonpenetrating AHT, (b) their relationship to other classic neuroimaging findings of AHT, and (c) their correlation with clinical outcomes.

METHODS

Diffusion-weighted imaging sequences of magnetic resonance imagings performed on children under 5 years diagnosed with AHT were reviewed to detect the most common patterns of acute parenchymal damage. Patterns of cytotoxic edema were described, and HII-compatible ones divided in subtypes. Correlation between HII, fractures, and subdural hemorrhages (SDHs) and with clinical outcomes was determined using imaging and available follow-up data.

RESULTS

Out of 57 patients, 36.8% showed lesions compatible with HII. A predominantly asymmetric cortical distribution was observed in 66.7% of cases, while 33.3% had diffused both cortical and deep gray/white matter distribution injury. Traumatic axonal injuries and focal contusions were less common. There was no significant correlation between the presence of SDH (P = .6) or skull fractures (P = .53) and HII. HII was the most severe form of parenchymal damage in terms of in-hospital mortality and morbidity at follow-up.

CONCLUSIONS

HII is the most common type of parenchymal damage in children victim of AHT, being present in 1/3 of patients with this condition, and correlates with more severe outcomes. Its presence is independent from other classic traumatic findings such as SDH and fractures.

The Eye Examination in the Evaluation of Child Abuse

Child abuse can cause injury to any part of the eye. The most common manifestations are retinal hemorrhages (RHs) in infants and young children with abusive head trauma (AHT). Although RHs are an important indicator of possible AHT, they are also found in other conditions. Distinguishing the number, type, location, and pattern of RHs is important in evaluating a differential diagnosis. Eye trauma can be seen in cases of physical abuse or AHT and may prompt referral for ophthalmologic assessment. Physicians have a responsibility to consider abuse in the differential diagnosis of pediatric eye trauma. Identification and documentation of inflicted ocular trauma requires a thorough examination by an ophthalmologist, including indirect ophthalmoscopy, most optimally through a dilated pupil, especially for the evaluation of possible RHs. An eye examination is helpful in detecting abnormalities that can help identify a medical or traumatic etiology for previously well young children who experience unexpected and unexplained mental status changes with no obvious cause, children with head trauma that results in significant intracranial hemorrhage and brain injury, and children with unexplained death.

A systematic autopsy survey of human infant bridging veins

In the first years of life, subdural haemorrhage (SDH) within the cranial cavity can occur through accidental and non-accidental mechanisms as well as from birth-related injury. This type of bleeding is the most common finding in victims of abusive head trauma (AHT). Historically, the most frequent cause of SDHs in infancy is suggested to be traumatic damage to bridging veins traversing from the brain to the dural membrane. However, several alternative hypotheses have been suggested for the cause and origin of subdural bleeding. It has also been suggested by some that bridging veins are too large to rupture through the forces associated with AHT. To date, there have been no systematic anatomical studies on infant bridging veins. During 43 neonatal, infant and young child post-mortem examinations, we have mapped the locations and numbers of bridging veins onto a 3D model of the surface of a representative infant brain. We have also recorded the in situ diameter of 79 bridging veins from two neonatal, one infant and two young children at post-mortem examination. Large numbers of veins, both distant from and directly entering the dural venous sinuses, were discovered travelling between the brain and dural membrane, with the mean number of veins per brain being 54.1 and the largest number recorded as 94. The mean diameter of the bridging veins was 0.93 mm, with measurements ranging from 0.05 to 3.07 mm. These data demonstrate that some veins are extremely small and subjectively, and they appear to be delicate. Characterisation of infant bridging veins will contribute to the current understanding of potential vascular sources of subdural bleeding and could also be used to further develop computational models of infant head injury.

Neonatal subcortical bruising

A specific type of acute brain injury can occur during birth, presenting on ultrasound examination with focal, unilateral, or asymmetrical change in the core of the superior frontal gyri. Ultrasound inspection of the superior gyri near the convexity of the frontal lobe is warranted following mechanically difficult delivery.

The Promise of Molecular Autopsy in Forensic Pathology Practice

Molecular autopsy is changing the practice of forensic pathology. Under some circumstances, one must contemplate the involvement of genetic factors to help explain why someone has died unexpectedly. Such considerations most commonly occur when a young person dies by natural means. However, there are deaths that occur by nonnatural means that the forensic pathologist will be asked to investigate, which could involve natural disease that has a significant genetic underpinning. Elucidation of genetic mutations may not only further an understanding of the pathophysiology at hand, but also speak to underlying susceptibilities in an individual who dies that may not have been recognized. In addition, one may occasionally identify pathological findings that are confused for trauma that may actually be better explained by an underlying disease process. Using molecular medicine as a tool to explore such possibilities can improve the quality of death investigations and provide a new lens to probe challenging and contentious forensic cases that have proved resistant to traditional methods.

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).

Evaluation of the Hypothesis That Choking/ALTE May Mimic Abusive Head Trauma

OBJECTIVE

Apparent life-threatening events (ALTEs), often accompanied by choking, have been hypothesized to cause subdural hemorrhages (SDH), retinal hemorrhages, and brain injury. If the choking/ALTE hypothesis were true, children who present with ALTE and SDH would have fewer extracranial injuries suspicious for abuse than those with SDH and no ALTE. We aimed to compare the prevalence of suspicious extracranial injuries in children who have ALTE-associated SDH to those with non-ALTE SDH.

METHODS

We performed a 5-year retrospective case-control study of children <2 years of age with SDH evaluated by the Child Abuse Pediatrics program at a children's hospital. Subjects were classified as ALTE-associated SDH and non-ALTE SDH on the basis of ALTE definitions as proposed by the authors of the choking/ALTE hypothesis. The 2 groups were compared for the prevalence of suspicious extracranial injuries.

RESULTS

Of 170 study subjects, 64 had an ALTE-associated SDH and 106 had non-ALTE SDH. ALTE-associated SDH subjects were nearly 5 times more likely to have at least one suspicious extracranial injury (odds ratio [OR] 4.8, 95% confidence interval [CI] 1.9-12.1) and were more likely to have individual types of suspicious extracranial injuries, including retinoschisis (OR 4.1, 95% CI 1.6-10.2), high-specificity bruising (OR 2.6, 95% CI 1.3-4.9), and internal abdominal injury (3.5, 95% CI 1.2-9.9). Subjects with ALTE-associated SDH were also significantly more likely to die or have persistent neurologic impairment. All 10 subjects with a dysphagic-choking type ALTE had at least 1 suspicious extracranial injury.

CONCLUSIONS

ALTEs are not supported as causative mechanisms for findings concerning abusive head trauma.

The importance of optic nerve sheath hemorrhage as a postmortem finding in cases of fatal abusive head trauma: A 13-year study in a tertiary hospital

Fatal abusive head trauma is a major cause of death in children and toddlers who suffer from cruel physical abuse. Postmortem differentiation of fatal abusive head trauma from accidental head trauma can be a complicated process. This consecutive case series study aimed to determine the role of subdural optic nerve sheath hemorrhage (ONSH) in 70 autopsy cases of children ≤3 years old in making this differentiation. The study took place over a 13 year period (between August 1st 2003 and July 31st 2016) at a tertiary hospital in Thailand. Eleven cases were diagnosed with fatal abusive head trauma and 10 were identified as being accidental closed head trauma cases. Bilateral retinal hemorrhage was noted in antemortem medical records in every hospitalized abusive head trauma case (n=10). Upon autopsy, ONSH was observed in all 11 fatal cases of abusive head trauma (bilateral=10 and unilateral=1) but not in any cases of accidental head trauma (0/5). Subdural hemorrhage was found in 10 out of 11 abusive head trauma victims but not in any of the 10 with accidental head trauma. Other postmortem findings in abusive head trauma included subarachnoid hemorrhage (5/11), marked brain swelling (3/11), skull fracture (4/11) and brain contusion (1/11). This study suggests that ONSH, together with subdural hemorrhage, plays an essential role in an accurate postmortem diagnosis of fatal abusive head trauma. Therefore, an ocular investigation should be performed in all autopsy cases where child abuse is suspected and where there is no reliable history/witnesses, confession or antemortem ophthalmologic examination.

Immobile cerebral veins in the context of positional brain shift: an undescribed risk factor for acute subdural hemorrhage

BACKGROUND

Changes in head position are thought to cause a degree of brain shift in the intracranial cavity. However, little is known on the concurrent shift of the cerebral veins. The present study aimed to investigate the positional shift of the cerebral veins that accompanies brain shift.

METHODS

Sagittal T2-weighted magnetic resonance imaging was performed on 21 consecutive patients lying in the supine and prone positions, using the same sequence. For each patient, imaging data were obtained for the two positions as a pair of images with morphologically best-matched cerebral contours.

RESULTS

The subarachnoid spaces in the parasagittal frontal convexity showed variable reductions related to a postural change from a supine to a prone position, with a mean percent reduction (%Δ) of 17.8 ± 11.7%. Additionally, cerebral cisterns ventral to the brainstem and upper cervical cord were reduced in most patients when lying in a prone position, with a mean %Δ of 16.6 ± 8.7%. In contrast, none of these 130 pairs of identical venous segments located in the parasagittal cerebral convexity showed positional shift. Cadaveric dissections found that the major cortical veins were superficially upheld by the arachnoid membranes.

CONCLUSIONS

The parasagittal major cortical and bridging veins do not seem to show positional shifts. Positional change in the posterior-anterior direction causes a shearing between the frontal cortices and the distributing veins and can be a risk factor for acute subdural hemorrhage, in case of severe head trauma.

A Conceptual Overview of Axonopathy in Infants and Children with Allegedly Inflicted Head Trauma

Fatal, allegedly inflicted pediatric head trauma remains a controversial topic in forensic pathology. Recommendations for systematic neuropathologic evaluation of the brains of supposedly injured infants and children usually include the assessment of long white matter tracts in search of axonopathy - specifically, diffuse axonal injury. The ability to recognize, document, and interpret injuries to axons has significant academic and medicolegal implications. For example, more than two decades of inconsistent nosology have resulted in confusion about the definition of diffuse axonal injury between various medical disciplines including radiology, neurosurgery, pediatrics, neuropathology, and forensic pathology. Furthermore, in the pediatric setting, acceptance that "pure" shaking can cause axonal shearing in infants and young children is not widespread. Additionally, controversy abounds whether or not axonal trauma can be identified within regions of white matter ischemia - a debate with very significant implications. Immunohistochemistry is often used not only to document axonal injury, but also to estimate the time since injury. As a result, the estimated post-injury interval may then be used by law enforcement officers and prosecutors to narrow "exclusive opportunity" and thus, identify potential suspects. Fundamental to these highly complicated and controversial topics is a philosophical understanding of the diffuse axonal injury spectrum disorders.

Infants dying suddenly and unexpectedly share demographic features with infants who die with retinal and dural bleeding: a review of neural mechanisms

The cause of death in infants who die suddenly and unexpectedly (sudden unexpected death in infancy [SUDI]) remains a diagnostic challenge. Some infants have identified diseases (explained SUDI); those without explanation are called sudden infant death syndrome (SIDS). Demographic data indicate subgroups among SUDI and SIDS cases, such as unsafe sleeping and apparent life-threatening events. Infants dying suddenly with retinal and dural bleeding are often classified as abused, but in many there is no evidence of trauma. Demographic features suggest that they may represent a further subgroup of SUDI. This review examines the neuropathological hypotheses to explain SIDS and highlights the interaction of infant oxygen-conserving reflexes with the brainstem networks considered responsible for SIDS. We consider sex- and age-specific vulnerabilities related to dural bleeding and how sensitization of the dural innervation by bleeding may influence these reflexes, potentially leading to collapse or even death after otherwise trivial insults.

Evaluation of Temporal Association Between Vaccinations and Retinal Hemorrhage in Children

IMPORTANCE

Vaccinations have been proposed as a cause of retinal hemorrhage in children, primarily as part of a defense strategy in high-stakes abusive head trauma cases. If vaccination injections cause retinal hemorrhage, this consideration would affect the evaluation of children for suspected child abuse.

OBJECTIVES

To describe the prevalence and causes of retinal hemorrhage among infants and young children in an outpatient ophthalmology clinic and to test the hypothesis that, if vaccination injections cause retinal hemorrhage, then retinal hemorrhage would be seen frequently and be temporally associated with immunization.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study between June 1, 2009, and August 30, 2012, at The Children's Hospital of Philadelphia pediatric ophthalmology clinics among 5177 children 1 to 23 months old undergoing a dilated fundus examination as an outpatient for any reason. Children with intraocular surgery or active retinal neovascularization were excluded from the study.

MAIN OUTCOMES AND MEASURES

The prevalence and causes of retinal hemorrhage, as well as the temporal association between vaccination injection within 7, 14, or 21 days preceding examination and retinal hemorrhage.

RESULTS

Among 7675 outpatient fundus examinations, 9 of 5177 children had retinal hemorrhage for a prevalence of 0.17% (95% CI, 0.09%-0.33%). All 9 had abusive head trauma diagnosable with nonocular findings. Among a subset of 2210 children who had complete immunization records and underwent 3425 fundoscopic examinations, 163 children had an eye examination within 7 days of vaccination, 323 within 14 days, and 494 within 21 days. No children had retinal hemorrhage within 7 days of vaccination, 1 child had hemorrhage within 14 days, and no additional child had hemorrhage within 21 days. There was no temporal association between vaccination injection and retinal hemorrhage in the prior 7 days (P > .99), 14 days (P = .33), or 21 days (P = .46).

CONCLUSIONS AND RELEVANCE

Retinal hemorrhage was rare among outpatients younger than 2 years. Considering both immediate and delayed effects, no temporal association existed between vaccination injection and retinal hemorrhage. Vaccination injections should not be considered a potential cause of retinal hemorrhage in children, and this unsupported theory should not be accepted clinically or in legal proceedings. Ophthalmologists noting incidental retinal hemorrhage on an outpatient examination should consider a child abuse evaluation in the absence of other known ocular or medical disease.

The optic nerve sheath hemorrhage is a non-specific finding in cases of suspected child abuse

In young infants, the triad consisting of acute encephalopathy, retinal hemorrhages, and a subdural hematoma is a nonspecific finding. It has traumatic and non-traumatic etiologies. The triad may be found among a vast spectrum of natural diseases. Optic nerve sheath hemorrhage in infants is typically detected at autopsy. It is a nonspecific finding that can be found in traumatic and non-traumatic etiologies. Neither the triad nor the ONSH are pathognomonic for an abusive head injury. Opposite to the triad, the spectrum of non-traumatic etiologies of ONSH is limited. In infants ONSH rarely occurs in spontaneous subarachnoidal hemorrhage or in infectious conditions. Our results show that the clinical significance of the optic nerve sheath hemorrhage in the forensic work-up of fatal cases of alleged abusive head injury is its limited differential diagnosis. Only after careful differential diagnosis ONSH may contribute to the diagnosis of AHT. However, the main limitation of our study is the sampling bias, as the eyes are usually removed when abusive head trauma is suspected.

Children and youth with 'unspecified injury to the head': implications for traumatic brain injury research and surveillance

Background

The case definition for traumatic brain injury (TBI) often includes ‘unspecified injury to the head’ diagnostic codes. However, research has shown that the inclusion of these codes leads to false positives. As such, it is important to determine the degree to which inclusion of these codes affect the overall numbers and profiles of the TBI population. The objective of this paper was to profile and compare the demographic and clinical characteristics, intention and mechanism of injury, and discharge disposition of hospitalized children and youth aged 19 years and under using (1) an inclusive TBI case definition that included ‘unspecified injury to the head’ diagnostic codes, (2) a restricted TBI case definition that excluded ‘unspecified injury to the head ‘diagnostic codes, and (3) the ‘unspecified injury to the head’ only case definition.

Methods

The National Ambulatory Care Reporting System and the Discharge Abstract Database from Ontario, Canada, were used to identify cases between fiscal years 2003/04 and 2009/10.

Results

The rate of TBI episodes of care using the inclusive case definition for TBI (2,667.2 per 100,000) was 1.65 times higher than that of the restricted case definition (1,613.3 per 100,000). ‘Unspecified injury to the head’ diagnostic codes made up of 39.5 % of all cases identified with the inclusive case definition. Exclusion of ‘unspecified injury to the head’ diagnostic code in the TBI case definition resulted in a significantly higher proportion of patients in the intensive care units (p < .0001; 18.5 % vs. 22.2 %) and discharged to a non-home setting (p < .0001; 9.9 % vs. 11.6 %).

Conclusion

Inclusion of ‘unspecified injury to the head’ diagnostic codes resulted in significant changes in numbers, healthcare use, and causes of TBI. Careful consideration of the inclusion of ‘unspecified injury to the head’ diagnostic codes in the case definition of TBI for the children and youth population is important, as it has implications for the numbers used for policy, resource allocation, prevention, and planning of healthcare services. This paper can inform future work on reaching consensus on the diagnostic codes for defining TBI in children and youth.

Cerebral Infarction following Acute Subdural Hematoma in Infants and Young Children: Predictors and Significance of FLAIR Vessel Hyperintensity

A phenomenon of cerebral infarction following acute subdural hematoma (ASDH) in infants and young children, termed cerebral infarction following ASDH (CIASDH), has been well recognized, though both its mechanisms and risk factors have been poorly understood. The purpose of the present study was to investigate the predictors for CIASDH in a population of ASDH, and to evaluate the imaging studies to presume the mechanisms of CIASDH. We retrospectively examined consecutive children 6 years of age or younger, who were diagnosed with ASDH and were admitted to our hospital between 2000 and 2014. In 57 consecutive children with ASDH, 12 (21.1%) developed CIASDH. The multivariate analysis revealed five predictors for CIASDH: presence of seizure, consciousness disturbance at admission, absence of skull fracture, hematoma thickness ≥ 5 mm on computed tomography (CT), and midline shift ≥ 3 mm on CT (p < 0.05). In three of six patients (50%) undergoing magnetic resonance (MR) imaging/fluid-attenuated inversion recovery (FLAIR) within 5 days of admission, serpentine hyperintensities in the subarachnoid space (FLAIR vessel hyperintensities) were demonstrated. MR angiography showed neither occlusion nor stenosis of the cerebral arteries. Single photon emission CT performed at admission in one patient showed a cerebral blood flow reduction in the ASDH side. All the children with CIASDH showed unfavorable outcomes at discharge. Children showing multiple predictors at admission should be carefully observed for development of CIASDH. Evaluation of the imaging studies suggested that a blood flow disturbance in the level of peripheral arteries to microcirculation was one candidate for possible mechanisms to induce the CIASDH.

Subdural hygromas in abusive head trauma: pathogenesis, diagnosis, and forensic implications

Are subdural hygromas the result of abusive head trauma? CT and MR imaging represent important tools for the diagnosis of abusive head trauma in living infants. In addition, in-depth understanding of the pathogenesis of subdural hygromas is increasingly required by neuroradiologists, pediatricians, and forensic physicians. Therefore, the current knowledge on subdural hygromas is summarized and forensic conclusions are drawn. The most important diagnostic pitfalls, benign enlargement of the subarachnoid space, and chronic subdural hematoma, are discussed in detail. Illustrative cases from forensic practice are presented. Literature analysis indicates that subdural hygromas can occur immediately or be delayed. If other infrequent reasons can be excluded, the presence of subdural hygromas strongly suggests a posttraumatic state and should prompt the physician to search for other signs of abuse. To differentiate subdural hygromas from other pathologies, additional MR imaging of the infant's head is indispensable after initial CT scan.

Mechanics of the brain: perspectives, challenges, and opportunities

The human brain is the continuous subject of extensive investigation aimed at understanding its behavior and function. Despite a clear evidence that mechanical factors play an important role in regulating brain activity, current research efforts focus mainly on the biochemical or electrophysiological activity of the brain. Here, we show that classical mechanical concepts including deformations, stretch, strain, strain rate, pressure, and stress play a crucial role in modulating both brain form and brain function. This opinion piece synthesizes expertise in applied mathematics, solid and fluid mechanics, biomechanics, experimentation, material sciences, neuropathology, and neurosurgery to address today’s open questions at the forefront of neuromechanics. We critically review the current literature and discuss challenges related to neurodevelopment, cerebral edema, lissencephaly, polymicrogyria, hydrocephaly, craniectomy, spinal cord injury, tumor growth, traumatic brain injury, and shaken baby syndrome. The multi-disciplinary analysis of these various phenomena and pathologies presents new opportunities and suggests that mechanical modeling is a central tool to bridge the scales by synthesizing information from the molecular via the cellular and tissue all the way to the organ level.

Defining pediatric traumatic brain injury using International Classification of Diseases Version 10 Codes: a systematic review

BACKGROUND

Although healthcare administrative data are commonly used for traumatic brain injury (TBI) research, there is currently no consensus or consistency on the International Classification of Diseases Version 10 (ICD-10) codes used to define TBI among children and youth internationally. This study systematically reviewed the literature to explore the range of ICD-10 codes that are used to define TBI in this population. The identification of the range of ICD-10 codes to define this population in administrative data is crucial, as it has implications for policy, resource allocation, planning of healthcare services, and prevention strategies.

METHODS

The databases MEDLINE, MEDLINE In-Process, Embase, PsychINFO, CINAHL, SPORTDiscus, and Cochrane Database of Systematic Reviews were systematically searched. Grey literature was searched using Grey Matters and Google. Reference lists of included articles were also searched for relevant studies. Two reviewers independently screened all titles and abstracts using pre-defined inclusion and exclusion criteria. A full text screen was conducted on articles that met the first screen inclusion criteria. All full text articles that met the pre-defined inclusion criteria were included for analysis in this systematic review.

RESULTS

A total of 1,326 publications were identified through the predetermined search strategy and 32 articles/reports met all eligibility criteria for inclusion in this review. Five articles specifically examined children and youth aged 19 years or under with TBI. ICD-10 case definitions ranged from the broad injuries to the head codes (ICD-10 S00 to S09) to concussion only (S06.0). There was overwhelming consensus on the inclusion of ICD-10 code S06, intracranial injury, while codes S00 (superficial injury of the head), S03 (dislocation, sprain, and strain of joints and ligaments of head), and S05 (injury of eye and orbit) were only used by articles that examined head injury, none of which specifically examined children and youth.

CONCLUSION

This review provides evidence for discussion on how best to use ICD codes for different goals. This is an important first step in reaching an appropriate definition and can inform future work on reaching consensus on the ICD-10 codes to define TBI for this vulnerable population.

Subdural hemorrhage and hypoxia in infants with congenital heart disease

BACKGROUND AND OBJECTIVES

It has been suggested that there is a causal relationship between hypoxia and subdural hemorrhage (SDH) in infancy. The purpose of this study was to review the incidence of SDH in infants with congenital heart disease and explore the relationship between SDH and hypoxia.

METHODS

Review of data collected for a prospective longitudinal cohort study of infants undergoing surgery for congenital heart disease in New Zealand and Australia. Infants underwent serial MRI scans of the brain in the first 3 months of life. All oxygen saturation recordings and MRI results were extracted and infants assigned to categories by degree of hypoxia. The data were then examined for any statistically significant relationship between hypoxia and SDH.

RESULTS

One hundred fifty-two infants underwent MRI scans, and 66 (43%) had 145 loci of SDH. New SDH was seen in 12 infants after cardiac surgery. Of the loci of SDH, 63 (43%) were supratentorial, and most of these were interhemispheric, parietal, or temporal. SDH present on the first MRI persisted beyond 28 days of life in 8 infants. There was no demonstrable relationship between SDH and hypoxia.

CONCLUSIONS

Asymptomatic SDH is common in young infants with congenital heart disease, at a frequency similar to that of those without congenital heart disease. These SDHs may occur in locations where they occur in abusive head trauma, but they are typically small and resolve within 3 months of birth. We were unable to demonstrate any association between hypoxia and SDH in this cohort.