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

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.

Overturned abusive head trauma and shaken baby syndrome convictions in the United States: Prevalence, legal basis, and medical evidence

BACKGROUND

Media reports and the Innocence Network assert that wrongful Abusive Head Trauma (AHT)/Shaken Baby Syndrome (SBS) convictions pervade the United States (U.S.) criminal justice system. Yet, no empirical evaluation of overturned AHT/SBS convictions has been conducted.

OBJECTIVE

To evaluate the prevalence, legal basis, and characteristics of appellate rulings of AHT/SBS convictions.

PARTICIPANTS AND SETTING

U.S. appellate cases in a legal database, Westlaw.

METHODS

Retrospective review of AHT/SBS convictions that had appellate rulings from January 2008 through December 2018. Multiple search terms ensured all potential AHT/SBS cases were included. A mixed-methods analysis was conducted on overturned AHT/SBS convictions.

RESULTS

We identified a total of 1431 unique AHT/SBS criminal convictions that had appellate rulings since 2008. Of those, 49 convictions (3%) were overturned, and 1382 (97%) were affirmed/upheld. Of those overturned, 20 cases (1% overall) were overturned on medical evidence-related grounds. The most common themes from the medical evidence-related reversals were controversy over the AHT/SBS diagnosis (n = 12) and accidental injury mechanism (n = 11). After being overturned on appeal, upon retrial, 42% of defendants either re-plead guilty to or were convicted again of the same offense.

CONCLUSION(S)

AHT/SBS convictions are rarely overturned on medical evidence-related grounds. When overturned, medical evidence-related themes seldom reflect new scientific or clinical discoveries, but rather are alternative or differing medical opinions from those offered at the original trial. Our data tends to support the concerns of other authors regarding irresponsible communication of medical information in AHT/SBS cases.

Subdural hemorrhage in a cohort with cerebral sinovenous thrombosis: Application to abusive head trauma

BACKGROUND

Cerebral sinovenous thrombosis (CSVT) is a postulated cause of subdural hemorrhage (SDH) that is hypothesized to mimic abusive head trauma (AHT). Minimal data exists directly investigating this relationship.

OBJECTIVES

To evaluate the frequency of SDH in children with CSVT, identify factors associated with CSVT and SDH, and to assess if any association supports the hypothesis that CSVT causes SDH.

PARTICIPANTS AND SETTING

The International Pediatric Stroke Study (IPSS) prospectively collects data on subjects birth to 19 years of age with intracranial thrombosis.

METHODS

IPSS subjects with CSVT and SDH were compared to those with CSVT and no SDH. For subjects with CSVT and SDH, neuroimaging reports further characterized the findings. In any case with no known risk factors for SDH, neuroimaging studies were reviewed by a pediatric neuroradiologist.

RESULTS

Of 216 subjects with CSVT, 20 (9.3%) had SDH. Those with SDH (median age 0.3 years) were younger than those without SDH (median age 4.2 years), p < 0.001. Subjects with CSVT and SDH more frequently had anoxia (OR = 10.8; 95% CI: 1.4, 81.1), head/neck injury (OR = 4.0; 95% CI: 1.3, 12.6), or abnormal consciousness (OR = 3.0; 95% CI: 1.2, 7.6). Of 20 subjects with CSVT and SDH, 19 had known risk factors for SDH. The remaining subject had a chronic SDH identified concomitantly to a newly symptomatic CSVT with accompanying venous infarctions.

CONCLUSIONS

SDH in the setting of CSVT is typically identified in children with independent risk factors for SDH. This study does not support the hypothesis that CSVT causes SDH.

Macrocephaly and subdural collections

Enlarged subarachnoid spaces are a common finding in infants and young children imaged for macrocephaly or an enlarging head circumference, and benign enlargement of the subarachnoid spaces is often diagnosed. Infrequently, presumed "spontaneous" subdural hemorrhages or subdural collections might complicate these enlarged subarachnoid spaces. Children with large bilateral subdural collections might also present for imaging with macrocephaly. Each scenario potentially raises concerns for prior injury because subdural hemorrhage is a frequent finding in children with abusive head trauma.

Implementation of a Comprehensive Safety Bundle to Support Newborn Fall/Drop Event Prevention and Response

OBJECTIVE

To create a comprehensive newborn fall/drop event prevention and response strategy in the form of a Newborn Fall Safety Bundle and to reduce newborn fall/drop events across an eight-hospital health system.

DESIGN

A performance improvement initiative guided by the Plan-Do-Study-Act model.

SETTING/LOCAL PROBLEM

A nonprofit health system consisting of one tertiary care center, three community hospitals, and four critical access hospitals. An increase in newborn fall/drop events was noted at one community hospital, with more than double the number of events being reported during fiscal year 2016 (five events) compared with fiscal year 2015 (two events). Injuries included skull fracture and hematoma, resulting in NICU admission and prolonged hospitalization.

PARTICIPANTS

Bedside registered nurses, educators, physicians, and nursing leadership representatives from tertiary, community, and critical access settings who formed a task force to identify and mitigate contributing factors, improve patient safety, and reduce newborn fall/drop events.

INTERVENTION/MEASUREMENTS

An evaluation of the problem was undertaken using root cause analysis and Pareto principles. Gaps were prioritized, and focus areas were identified. Evidence-based interventions were organized into a Newborn Fall Safety Bundle. Process and outcome metrics were tracked as measures of improvement.

RESULTS

Practice alignment with the Newborn Fall Safety Bundle was sustained at 90% or greater. Overall, the organization realized a 36% reduction in the newborn fall/drop event rate between fiscal year 2016 and fiscal year 2017. Rates declined from 6.66 to 4.06 newborn fall/drop events per 10,000 births. At the pilot site, newborn fall/drop event rates decreased from 21.95 to 0 events per 10,000 births over the same time period.

CONCLUSION

A reduction in newborn fall/drop events was observed after implementation of a comprehensive Newborn Fall Safety Bundle.

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.

Medical diagnoses among infants at entry in out-of-home care: A Swedish population-register study

BACKGROUND AND AIMS

Identification of child abuse involves a medical investigation and assessment of problems related to social environment and upbringing and might necessitate out-of-home care. The objective of this study was to analyse infants placed in out-of-home care in Sweden by incidence, medical diagnoses, and perinatal factors.

METHODS

This was a population-based register study of infants born in Sweden 1997 to 2014. Data were retrieved from registers at the Swedish National Board of Health and Welfare and Statistics Sweden. Outcome measures were out-of-home care categories: (a) "Problems Related to Social Environment/Upbringing", (b) "Abuse diagnoses without SDH (subdural haemorrhage), RH (retinal haemorrhage), rib fracture, or long bone fracture", and (c) "SDH, RH, rib fracture, or long bone fracture." As a reference population, we randomly selected infants without medical diagnoses born the same year.

RESULTS

Overall incidence of out-of-home care was 402 per 100 000. For subcategories (a), (b), and (c), the incidences were 14.8 (n = 273), 3.77 (n = 70), and 9.83 (n = 182) per 100 000, respectively. During the study period, the first remained unchanged; the latter two have been increasing. Compared with other reasons for out-of-home care, children in category (c), "SDH, RH, rib fracture, or long bone fracture", had increased odds of being boys (adjusted odds ratio [aOR] 1.60; 95% confidence interval [CI], 1.08-2.38) and decreased odds of having a mother being single (aOR 0.49; 95% CI, 0.32-0.75) and a smoker (aOR 0.60; 95% CI, 0.37-0.96). Compared with the reference population, children in this category were more often twin born (7.7% versus 2.8%), preterm (18.5% versus 5.5%), and small-for-gestational age (5.2% versus 2.1%).

CONCLUSION

SDH, RH, rib fracture, or long bone fracture constitute a minor part of medical diagnoses for infants entered in out-of-home care, but have been increasing, both in numbers and proportion. Overdiagnosis of abuse might be a possible reason but cannot be ascertained by this study design.

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

Background

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

Methods

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

Results

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

Conclusions

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

The pathology and aetiology of subcortical clefts in infants

In infants, traumatic surface contusions of the brain are rare but subcortical clefts or cysts, variously labelled "contusional tears", "contusional clefts", "cortical tears" or "parenchymal lacerations" have been ascribed to trauma, and are even said to be characteristic of shaking and abuse. We describe the pathology of subcortical clefts or haemorrhages in seven infants. In none were the axonal swellings characteristic of traumatic axonal injury seen in relation to the clefts. Subpial bleeding was associated with clefts in all the cases of recent onset. We hypothesize that subcortical clefts are not due to direct mechanical forces of trauma but are part of a secondary cascade caused by impaired venous drainage which may or may not follow trauma. The finding of subcortical and subpial haemorrhages should prompt a search for CVT. We consider the term "contusion" is not accurate and is misleading.

The neuroimaging mimics of abusive head trauma

Abusive head trauma (AHT) is a significant cause of morbidity and mortality in the paediatric population, typically in children under the age of two years. Neuroimaging plays a key role in the diagnostic work up of these patients as information regarding the mechanism of injury is often lacking and the findings on examination can be nonspecific. A number of conditions, both traumatic and atraumatic can mimic AHT based on neuroimaging features alone. The repercussions associated with a diagnosis or misdiagnosis of AHT can be severe and radiologists therefore need to be aware of and familiar with the imaging differentials of AHT. In this paper we review the imaging findings of the radiological mimics of AHT and focus on features that can help differentiate these entities from AHT.

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.

Consensus statement on abusive head trauma in infants and young children

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

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Early diffusion restriction of white matter in infants with small subdural hematomas is associated with delayed atrophy

BACKGROUND

Traumatic brain injury (TBI) is a major cause of infant morbidity and mortality. In these patients, magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) is the test of choice to describe the extent of microstructural injury.

CASE PRESENTATION AND DISCUSSION

In this case series, we describe novel acute and chronic MRI findings in four infants (6-19 months) with small, unilateral subdural hematomas in whom the etiology of head injury was suspicious for non-accidental trauma (NAT). Acute (<1-week post-injury) DWI revealed extensive areas of restricted diffusion isolated to the cerebral white matter predominantly ipsilateral to the subdural hematoma. After prolonged pediatric intensive care treatment including subdural evacuation (n = 2) or decompressive craniectomy (n = 1), all patients survived albeit with significant motor and cognitive deficits. Delayed structural MRI (6-9-year post-injury) demonstrated cortical and subcortical atrophy well-correlated with areas of acute restricted diffusion.

CONCLUSION

These four cases highlight that relatively small subdural hematomas can be associated with extensive white matter injury-detectable only by early DWI-which have long-term structural and functional consequences.

The significance of macrocephaly or enlarging head circumference in infants with the triad: further evidence of mimics of shaken baby syndrome

Infants with the triad (neurologic dysfunction, subdural hematoma [SDH], and retinal hemorrhage) are often diagnosed as victims of shaken baby syndrome. Medical conditions/predisposing factors to developing the triad are often dismissed: short falls, birth-related SDH that enlarges, macrocephaly, sinus/cortical vein thrombosis, and others. Six infants with the triad are described in which child abuse was diagnosed, but parents denied wrongdoing. All 6 had either macrocephaly or enlarging head circumference, which suggested medical explanations. Three infants incurred short falls, 1 had a difficult delivery in which there was likely a rebleed of a birth-related SDH, 1 had a spontaneous SDH associated with increased extra-axial fluid spaces, and 1 had a sinus thrombosis. Following legal proceedings, all 6 infants were returned to their parents, and there has been no child maltreatment in follow-up, suggesting child abuse never happened. The results indicate that alternative medical explanations for causing the triad should be considered and that macrocephaly or an enlarging head circumference raises the possibility of a medical explanation.

Venous injury in abusive head trauma

BACKGROUND

Abusive head trauma (AHT) is an important cause of serious brain injury in infants and young children who have characteristic clinical and imaging findings that are discordant with the clinical history provided. Recent attention has focused on abnormalities of the cranial venous sinuses and cortical veins, both on MRI and at autopsy. Although many have interpreted these to be secondary to the AHT, some have recently argued that these venous abnormalities represent primary cortical sinus and venous thrombosis that leads secondarily to subdural hemorrhage and secondary brain injury. Direct trauma to the veins and sinuses has been reported at autopsy in AHT, but there has been no systematic study of venous abnormalities in cases of AHT.

OBJECTIVE

The purpose of this study was to define the incidence and characteristics of venous and sinus abnormalities in AHT.

MATERIALS AND METHODS

We included all children <36 months of age who were diagnosed with abusive head trauma between 2001 and 2012 and who had MRI and magnetic resonance (MR) venography as part of their diagnostic workup. We analyzed age, gender and clinical findings. MRI and MR venography were analyzed independently by two neuroradiologists with a focus on abnormalities involving the intracranial veins and venous sinuses.

RESULTS

A total of 45 children were included. The median age was 3 months (range 15 days to 31 months) and 28 were boys (62%). Clinical findings included retinal hemorrhage in 71% and extracranial fractures in 55%. CT or MRI demonstrated subdural hemorrhage in 41 (91%); none had subdural effusions. In 31 cases (69%) MR venography demonstrated mass effect on the venous sinuses or cortical draining veins, with either displacement or partial or complete effacement of the venous structures from an adjacent subdural hematoma or brain swelling. We also describe the lollipop sign, which represents direct trauma to the cortical bridging veins and was present in 20/45 (44%) children.

CONCLUSION

Evidence of displacement or compression of cortical veins and sinuses from subdural hemorrhage or edema on MR venography was present in the majority of children with abusive head trauma. Evidence of direct trauma to the veins (lollipop sign) was identified in nearly half of cases. It is important to understand the superimposed effects of subdural hematoma and brain swelling on the veins and sinuses to differentiate it from cortical sinus and venous thrombosis.

Initial clinical presentation of children with acute and chronic versus acute subdural hemorrhage resulting from abusive head trauma

OBJECT At presentation, children who have experienced abusive head trauma (AHT) often have subdural hemorrhage (SDH) that is acute, chronic, or both. Controversy exists whether the acute SDH associated with chronic SDH results from trauma or from spontaneous rebleeding. The authors compared the clinical presentations of children with AHT and acute SDH with those having acute and chronic SDH (acute/chronic SDH). METHODS The study was a multicenter retrospective review of children who had experienced AHT during 2004-2009. The authors compared the clinical and radiological characteristics of children with acute SDH to those of children with acute/chronic SDH. RESULTS The study included 383 children with AHT and either acute SDH (n = 291) or acute/chronic SDH (n = 92). The children with acute/chronic SDH were younger, had higher initial Glasgow Coma Scale scores, fewer deaths, fewer skull fractures, less parenchymal brain injury, and fewer acute noncranial fractures than did children with acute SDH. No between-group differences were found for the proportion with retinal hemorrhages, healing noncranial fractures, or acute abusive bruises. A similar proportion (approximately 80%) of children with acute/chronic SDH and with acute SDH had retinal hemorrhages or acute or healing extracranial injures. Of children with acute/chronic SDH, 20% were neurologically asymptomatic at presentation; almost half of these children were seen for macrocephaly, and for all of them, the acute SDH was completely within the area of the chronic SDH. CONCLUSIONS Overall, the presenting clinical and radiological characteristics of children with acute SDH and acute/chronic SDH caused by AHT did not differ, suggesting that repeated abuse, rather than spontaneous rebleeding, is the etiology of most acute SDH in children with chronic SDH. However, more severe neurological symptoms were more common among children with acute SDH. Children with acute/chronic SDH and asymptomatic macrocephaly have unique risks and distinct radiological and clinical characteristics.

Recent progress and future issues in the management of abusive head trauma

Head trauma is the leading cause of death in child abuse cases and one of the important issues in the care of abused children. Since the Child Abuse Prevention Law was enforced in 2000 in Japan, various measures have been taken to prevent child abuse over the following decade. Accordingly, medical research on abusive head trauma (AHT) has advanced, leading to significant progress in the medical diagnosis of AHT. This progress has been brought about by (1) the widespread establishment of child protection teams (CPTs) at core hospitals, (2) the progress in neuroradiological imaging and ophthalmoscopic technologies, and (3) the introduction of postmortem imaging. However, the pathological condition of patients with AHT, particularly that of the diffuse brain swelling type, still remains poorly understood. As a result, no clear treatment strategies for AHT have been developed and no treatment outcomes have been improved to date. The development of new treatment strategies for AHT and the construction of a comprehensive database that supports clinical studies are required in the future.

Imaging abusive head trauma: why use both computed tomography and magnetic resonance imaging?

Abusive head trauma is the leading cause of death in child abuse cases. The majority of victims are infants younger than 1 year old, with the average age between 3 and 8 months, although these injuries can be seen in children up to 5 years old. Many victims have a history of previous abuse and the diagnosis is frequently delayed. Neuroimaging is often crucial for establishing the diagnosis of abusive head trauma as it detects occult injury in 37% of cases. Several imaging patterns are considered to be particularly associated with abusive head trauma. The presence of subdural hematoma, especially in multiple locations, such as the interhemispheric region, over the convexity and in the posterior fossa, is significantly associated with abusive head trauma. Although CT is the recommended first-line imaging modality for suspected abusive head trauma, early MRI is increasingly used alongside CT because it provides a better estimation of shear injuries, hypoxic-ischemic insult and the timing of lesions. This article presents a review of the use and clinical indications of the most pertinent neuroimaging modalities for the diagnosis of abusive head trauma, emphasizing the newer and more sensitive techniques that may be useful to better characterize the nature and evolution of the injury.

A critical review of the classic metaphyseal lesion: traumatic or metabolic?

OBJECTIVE

The purpose of this study was to review the hypothesis that classic metaphyseal lesions represent traumatic changes in abused infants and compare these lesions with healing rickets.

MATERIALS AND METHODS

Using a PubMed search, a multidisciplinary team reviewed studies that reported the histopathologic correlation of classic metaphyseal lesions. Selective studies of growth plate injury and rickets were cross-referenced.

RESULTS

Nine identified classic metaphyseal lesion studies were performed by the same principal investigator. Control subjects were inadequate. Details of abuse determination and metabolic bone disease exclusion were lacking. The presence of only a single radiology reviewer prevented establishment of interobserver variability. Microscopy was performed by two researchers who were not pathologists. Classic metaphyseal lesions have not been experimentally reproduced and are unrecognized in the accidental trauma literature. The proposed primary spongiosa location is inconsistent with the variable radiographic appearances. Classic metaphyseal lesions were not differentiated from tissue processing artifacts. Bleeding and callus were uncommon in spite of the vascular nature of the metaphysis. The conclusion that excessive hypertrophic chondrocytes secondary to vascular disruption were indicative of fracture healing contradicts the paucity of bleeding, callus, and periosteal reaction. Several similarities exist between classic metaphyseal lesions and healing rickets, including excessive hypertrophic chondrocytes. "Bucket-handle" and "corner fracture" classic metaphyseal lesions resemble healing rickets within the growth plate and the perichondrial ring, respectively. The age of presentation was more typical of bone fragility disorders, including rickets, than reported in prior child abuse series.

CONCLUSION

The hypothesis that classic metaphyseal lesions are secondary to child abuse is poorly supported. Their histologic and radiographic features are similar to healing infantile rickets. Until classic metaphyseal lesions are experimentally replicated and independently validated, their traumatic origin remains unsubstantiated.

Cerebral sinovenous thrombosis in pediatric practice

Cerebral sinovenous thrombosis (CSVT) in the pediatric population is a relatively uncommon yet under-appreciated and potentially life-threatening neurological condition. Early symptoms and signs are often vague and the clinician requesting a cranial imaging study might not even suspect sinovenous thrombosis. If left undiagnosed, or if the diagnosis of CSVT is delayed, progressive neurological deterioration, coma and death can follow. The purpose of this review is to highlight pertinent development of the cerebral venous system, discuss the causal factors of cerebral sinovenous thrombosis in the pediatric population, review practical imaging strategies using cranial sonography augmented with color and pulsed Doppler, unenhanced brain CT, CT venography, cerebral MRI, and MR venography (MRV). Finally, this review will illustrate the imaging features of sinovenous thrombosis, including a discussion of the common causes of false-positive and false-negative CT and MRI studies.

Does intracranial venous thrombosis cause subdural hemorrhage in the pediatric population?

Unexplained SDH in infants and children is an accepted marker for AHT. It has been proposed that IVT may be the initiating event leading to the development of acute SDH, mimicking the appearance of traumatic SDH. Our study aims to investigate if nontraumatic IVT causes SDH in the pediatric population. We retrospectively identified 36 patients with IVT and reviewed neuroimaging studies for the concurrent presence of SDH. In our 36 patients with IVT, no associated SDH was observed. Even with extensive IVT, no SDH was present. Three false-positive diagnoses of IVT were identified in the setting of mastoiditis and traumatic SDH, demonstrating pitfalls in imaging. In conclusion, our findings do not support the previous AHT literature stating that IVT is associated with, or leads to, SDH in neonates, infants, or children.

Pediatric neurocritical care

Pediatric neurocritical care is an emerging multidisciplinary field of medicine and a new frontier in pediatric critical care and pediatric neurology. Central to pediatric neurocritical care is the goal of improving outcomes in critically ill pediatric patients with neurological illness or injury and limiting secondary brain injury through optimal critical care delivery and the support of brain function. There is a pressing need for evidence based guidelines in pediatric neurocritical care, notably in pediatric traumatic brain injury and pediatric stroke. These diseases have distinct clinical and pathophysiological features that distinguish them from their adult counterparts and prevent the direct translation of the adult experience to pediatric patients. Increased attention is also being paid to the broader application of neuromonitoring and neuroprotective strategies in the pediatric intensive care unit, in both primary neurological and primary non-neurological disease states. Although much can be learned from the adult experience, there are important differences in the critically ill pediatric population and in the circumstances that surround the emergence of neurocritical care in pediatrics.

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.

Education of the child neurologist: traumatic brain injury

As traumatic brain injury is among the most common causes of pediatric mortality and neurologic morbidity, the well-trained child neurologist should have a solid foundation of the pathogenesis of traumatic brain injury and be competent in the acute and chronic management of children and adolescents who experience a traumatic brain injury. This article outlines the training goals and core knowledge of traumatic brain injury that should be attained by those training in child neurology by the completion of their formal training.