Spinal subdural haematomas in children with non-accidental head injury

Abusive spinal injury: imaging and updates

Child physical abuse has significant morbidity and mortality in the pediatric population. There is growing evidence that abusive spinal injury has been under-recognized, changing historical perceptions that these injuries are relatively uncommon. Increased utilization of MRI has been pivotal in recognizing that most abusive spinal injuries involve the soft tissues and ligaments or manifest as intrathecal blood products, which are often undetectable by radiography or CT. Detecting spinal injury in the work-up of non-accidental trauma improves management for abused children and their siblings (defined as siblings or other household members). This review highlights key points in the imaging literature of abusive spinal injury, describes typical patterns of injury, and addresses appropriate imaging practice for work-up.

Neuroimaging considerations in abusive head trauma

This focused review on abusive head trauma describes the injuries to the head, brain and/or spine of an infant or young child from inflicted trauma and their neuroimaging correlates. Accurate recognition and diagnosis of abusive head trauma is paramount to prevent repeated injury, provide timely treatment, and ensure that accidental or underlying medical contributors have been considered. In this article, we aim to discuss the various findings on neuroimaging that have been associated with AHT, compared to those that are more consistent with accidental injuries or with underlying medical causes that may also be on the differential.

Clinical and Forensic Investigation Protocols for Diagnosing Abusive Head Trauma: A Literature Review

Abusive head trauma (AHT) represents a very serious global public health problem. Prevention of these episodes is essential to reduce the morbidity and mortality of this phenomenon. All healthcare professionals should be able to recognize the signs of abuse. However, diagnosis is very complex as the signs are often blurred and cannot be recognized with certainty without carrying out adequate instrumental investigations. It has been calculated that approximately one-third of AHT cases remain undetected and require more than one medical visit to be correctly interpreted and diagnosed. On the other hand, the literature has recently also emphasized the problems related to possible false diagnoses of abuse and the numerous family and personal repercussions that follow from this issue. For these reasons, correct and timely recognition is essential to avoid the risk of recurrence of AHT and to start proper forensic investigations, in order to identify the offender or exonerate a suspect. The present work explores the most recent evidence of recent years in the field of AHT diagnostics through a literature review. The purpose of this article is to provide forensic pathologists with clear tools for diagnosis based on the literature. To this end, the review suggests clinical and forensic protocols aimed at the timely diagnosis of AHT in order to prevent abuse from remaining undetected.

Imaging of Abusive Head Trauma in Children

In this article, we describe relevant anatomy, mechanisms of injury, and imaging findings of abusive head trauma (AHT). We also briefly address certain mimics of AHT, controversies, pearls, and pitfalls. Concepts of injury, its evolution, and complex nature of certain cases are highlighted with the help of case vignettes.

Diagnosis of Abusive Head Trauma : Neurosurgical Perspective

Abusive head trauma (AHT) is the most severe form of physical abuse in children. Such injury involves traumatic damage to the head and/or spine of infants and young children. The term AHT was introduced to include a wider range of injury mechanisms, such as intentional direct blow, throw, and even penetrating trauma by perpetuator(s). Currently, it is recommended to replace the former term, shaken baby syndrome, which implicates shaking as the only mechanism, with AHT to include diverse clinical and radiological manifestations. The consequences of AHT cause devastating medical, social and financial burdens on families, communities, and victims. The potential harm of AHT to the developing brain and spinal cord of the victims is tremendous. Many studies have reported that the adverse effects of AHT are various and serious, such as blindness, mental retardation, physical limitation of daily activities and even psychological problems. Therefore, appropriate vigilance for the early recognition and diagnosis of AHT is highly recommended to stop and prevent further injuries. The aim of this review is to summarize the relevant evidence concerning the early recognition and diagnosis of AHT. To recognize this severe type of child abuse early, all health care providers maintain a high index of suspicion and vigilance. Such suspicion can be initiated with careful and thorough history taking and physical examinations. Previously developed clinical prediction rules can be helpful for decision-making regarding starting an investigation when considering meaningful findings. Even the combination of biochemical markers may be useful to predict AHT. For a more confirmative evaluation, neuroradiological imaging is required to find AHT-specific findings. Moreover, timely consultation with ophthalmologists is needed to find a very specific finding, retinal hemorrhage.

Whole spine MRI in children with suspected child abuse

Background: Abusive head trauma (AHT) in children has recently been associated with findings on cervical spine MRI. Objective: To evaluate whether whole-spine MRI in children suspected of AHT shows additional abnormalities not identified on cervical spine MRI. Methods: This retrospective study included 256 children young than 3 years (170 boys, 86 girls; mean age, 5.9 months) who underwent skeletal survey and head MRI for suspected child abuse from January 2019 to December 2020. Per institutional protocol, children with suspected AHT also underwent whole-spine MRI. AHT diagnoses were established by combination of clinical information from medical record review and injuries described in reports from skeletal survey, head MRI, and head CT (if performed). Two pediatric neuroradiologists independently reviewed whole-spine MRI examinations for presence and level of intraspinal hemorrhage (classified as subarachnoid, subdural, or epidural), ligamentous injury, spinal cord edema, and vertebral fractures; subdural hematoma, epidural hematoma, ligamentous injury, and fracture unidentified by skeletal survey were considered major findings. Interreader agreement was assessed; a third radiologist resolved discrepancies. Findings were summarized with attention to injuries isolated to the thoracolumbar spine. Results: A total of 148/256 (57.8%) children underwent whole-spine MRI. AHT was diagnosed in 79/148 (53.4%) children who underwent whole-spine MRI, versus in 2/108 (1.9%) who did not undergo whole-spine MRI (p<.001). Interobserver agreement. expressed as kappa, was 0.90 for intraspinal hemorrhage, 0.69 for ligamentous injury, 0.66 for spinal cord edema, and 0.95 for fracture. A total of 57/148 (38.5%) whole-spine MRI examinations demonstrated injuries; 34/148 (23.0%) demonstrated injuries localized to the thoracolumbar spine. A total of 47/148 (31.8%) whole-spine MRI examinations demonstrated major findings, of which 24/47 (51.1%) were localized to the thoracolumbar spine. Isolated thoracolumbar injuries included 23 of 34 subdural hematomas, 2 of 3 epidural hematomas, and 9 of 11 fractures, including 5 fractures not identified by skeletal survey. Diagnosis of AHT was more common in children with positive, versus negative, whole-spine MRI examinations (76.8% vs 39.1%, p<.001). Conclusion: In children with suspected AHT, whole-spine MRI commonly demonstrates isolated thoracolumbar injuries. Clinical Impact: The results support performing whole-spine MRI rather than cervical spine MRI in children with suspected AHT.

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.

Spinal subdural hemorrhage in abusive head trauma: a pictorial review

A growing body of evidence links abusive head trauma (AHT) to patterns of direct and indirect spinal injuries, such as spinal subdural hemorrhage (SDH). Identification of evidence of spinal injury such as spinal SDH plays a crucial role in the diagnosis and subsequent management of the index child with AHT and his or her siblings. In a value-based practice of medicine, it can be argued that adding spine imaging to identify spinal SDH in the workup of AHT adds value to both the short- and long-term management of the patient. This pictorial review describes the normal appearance of spinal SDH and challenges of identifying spinal SDH, and it explores the mechanism of spinal SDH development in AHT.

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.

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.

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.

Cervical spine imaging for young children with inflicted trauma: Expanding the injury pattern

AIM

The purpose of this study was to document the incidence and pattern of cervical spine (c-spine) injuries in children below 36months with inflicted trauma.

METHODS

An IRB approved, prospective cohort study was performed between July 2011 and January 2016. Inclusion criteria were: age below 36months, loss of consciousness after inflicted trauma, and one initial head computed tomography finding: a subdural, intraventricular, intraparenchymal, subarachnoid hemorrhage, diffuse axonal injury, hypoxic injury, or cerebral edema. A protocol of brain and neck magnetic resonance imaging and angiography was obtained within 48h. Variables were compared by t-test and Fisher-exact test.

RESULTS

There were 53 children (median age: five months; range: 1-35months), 38 males (71.7%), of which seven died (13.2%). C-spine injury was identified in 8 (15.1%): ligamentous injury (2), vertebral artery shear injury (1), atlantooccipital dissociation (AOD) (1), cord injury with cord epidural hematoma (2), and isolated cord epidural hematoma (2). Retinal hemorrhages (p=0.02), shaking (p=0.04), lower Glasgow coma score (GCS) (p=0.01), brain infarcts (p=0.01), and hypoxic/ischemic injury (p=0.01) were associated with c-spine injury. One with AOD died. Six had significant disability.

CONCLUSION

For small children with inflicted trauma, the c-spine injury incidence is 15.1%. The injury pattern includes retinal hemorrhages, shaking, lower GCS, and brain injury. Evaluation of shaken infants should include c-spine imaging.

LEVEL OF EVIDENCE

Level 2 A- This is a prospective cohort study with complete follow-up to hospital discharge or death. In all cases, inflicted trauma was confirmed. Owing to the nature of child abuse, the precise time of injury is not known. All children underwent a strict imaging protocol on arrival to hospital that was supervised on a prospective basis.

Spontaneous Resolution of Spinal Epidural Hematoma Resulting from Domestic Child Abuse: Case Report

Nonaccidental head injury, as seen in domestic child abuse cases, is often associated with spinal injury, and spinal subdural hematoma is the most frequent diagnosis. While spinal epidural hematomas are a rare occurrence, the incidence of spontaneous epidural hematomas occurring in nonaccidental head injury patients is even lower. Epidural hematomas often result in acute focal neurological deficits necessitating emergent neurosurgical intervention. In patients without focal neurological deficits, conservative management may allow for spontaneous resolution of the epidural hematoma. The authors present the case of a 2-year-old boy with a large spinal epidural hematoma resulting after an event of nonaccidental injury, specifically, domestic child abuse. This patient exhibited no focal neurological deficits and was managed conservatively without surgical clot evacuation. On a follow-up visit, repeat imaging studies demonstrated a stable resolution of spinal epidural hematoma, providing further support for the safety of conservative management in these patients.

MR Imaging of the Cervical Spine in Nonaccidental Trauma: A Tertiary Institution Experience

BACKGROUND AND PURPOSE

Cervical MR imaging has demonstrated a utility for detecting soft tissue injury in nonaccidental trauma. The purpose of this study was to identify the incidence and types of cervical spine injury on MR imaging in nonaccidental trauma and to correlate cervical spine injury with parenchymal injury on brain MR imaging and findings on head CT.

MATERIALS AND METHODS

A retrospective review of children diagnosed with nonaccidental trauma in a tertiary referral pediatric hospital over 8 years was performed. Inclusion criteria were children younger than 5 years of age, a confirmed diagnosis of nonaccidental trauma, and cervical spine MR imaging within 1 week of presentation. Brain and cervical spine MR imaging, head CT, cervical radiographs, and skeletal surveys were reviewed.

RESULTS

There were 89 patients included in this study (48 males; mean age, 9.1 months [range, 1-59 months]). Cervical spine injury on MR imaging was found in 61 patients (69%). Ligamentous injury was seen in 60 patients (67%), with interspinous ligaments being most commonly involved. Abnormal capsular fluid (atlanto-occipital and atlantoaxial) was present in 28 patients (32%). Cervical spine injury on MR imaging was significantly associated with parenchymal restricted diffusion on brain MR imaging and parenchymal injury on head CT (P = .0004 and P = .0104, respectively). Children with restricted diffusion on brain MR imaging were 6.22 (point estimate) times more likely to have cervical spine injury on MR imaging.

CONCLUSIONS

There is a high incidence of cervical spine injury in pediatric nonaccidental trauma. Positive findings may affect management and suggest a traumatic etiology.

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.

Abusive head trauma: past, present, and future

Abusive head trauma has a robust and interesting scientific history. Recently, the American Academy of Pediatrics has endorsed a change in terminology to a term that is more general in describing the vast array of abusive mechanisms that can result in pediatric head injury. Simply defined, abusive head trauma is "child physical abuse that results in injury to the head or brain." Abusive head trauma is a relatively common cause of childhood neurotrauma, with an estimated incidence of 16 to 33 cases per 100,000 children per year in the first 2 years of life. Clinical findings are variable; AHT should be considered in all children with neurologic signs and symptoms, especially if no or only mild trauma is described. Subdural and retinal hemorrhages are the most common findings. The current best evidence-based literature has identified some features--apnea and severe retinal hemorrhages--that reliably discriminate abusive from accidental injury. Longitudinal studies of outcomes in abusive head trauma patients demonstrate that approximately one-third of the children are severely disabled, one third of them are moderately disabled, and one third have no or only mild symptoms. Abusive head trauma cases are complex cases that require a rigorous, multidisciplinary team approach. The clinician can establish this diagnosis with confidence if he/she maintains a high index of suspicion for the diagnosis, has knowledge of the signs, symptoms, and risk factors of abusive head trauma, and reasonably excludes other etiologies on the differential diagnosis.

Spinal injuries in abusive head trauma: patterns and recommendations

A growing body of scientific evidence suggests that there is an association between occult spinal injury and abusive head trauma (previously known as shaken baby syndrome). Consideration needs to be given to the nature of these injuries, the possible causal mechanisms and what investigations should be undertaken to delineate the full extent of spinal involvement in infants with suspected abusive head trauma. This association has the potential to influence our understanding of the biomechanics and subsequent neuropathology associated with abusive head trauma.

Usefulness of MRI detection of cervical spine and brain injuries in the evaluation of abusive head trauma

BACKGROUND

In the evaluation of children younger than 3 years with intracranial hemorrhage it can be difficult to determine whether the cause of hemorrhage was traumatic, and if so, whether abusive head trauma (AHT) is a possibility. Cervical spine MRI is not a routine part of the nationally recommended imaging workup for children with suspected abusive head trauma. There is increasing evidence that spinal injuries are found at autopsy or MRI in abused children. However the prevalence of cervical spine injuries in children evaluated for abusive head trauma is unknown. We sought to determine both the incidence and the spectrum of cervical spine and brain injuries in children being evaluated for possible abusive head trauma. We also examined the relationship between cervical and brain MRI findings and selected study outcome categories.

MATERIALS AND METHODS

This study is a 3-year retrospective review of children evaluated for abusive head trauma. Inclusion criteria were: children with head trauma seen at our institution between 2008 and 2010, age younger than 36 months, availability of diagnostic-quality brain and cervical spine MRI, and child abuse team involvement because abusive head trauma was a possibility. A child abuse pediatrician and pediatric radiologists, all with board certification, were involved in data collection, image interpretation and data analysis. Statistical analysis was performed using Stata v12.1.

RESULTS

The study included 74 children (43 boys, 31 girls) with a mean age of 164 days (range, 20-679 days). Study outcomes were categorized as: n = 26 children with accidental head trauma, n = 38 with abusive head trauma (n = 18 presumptive AHT, n = 20 suspicious for AHT), and n = 10 with undefined head trauma. We found cervical spine injuries in 27/74 (36%) children. Most cervical spine injuries were ligamentous injuries. One child had intrathecal spinal blood and two had spinal cord edema; all three of these children had ligamentous injury. MRI signs of cervical injury did not show a statistically significant relationship with a study outcome of abusive head trauma or help discriminate between accidental and abusive head trauma. Of the 30 children with supratentorial brain injury, 16 (53%) had a bilateral hypoxic-ischemic pattern. There was a statistically significant relationship between bilateral hypoxic-ischemic brain injury pattern and abusive head trauma (P < 0.05). In addition, the majority (81%) of children with bilateral hypoxic-ischemic brain injuries had cervical injuries.

CONCLUSION

Although detection of cervical spine injuries by MRI does not discriminate between accidental and abusive head trauma, it can help to distinguish a traumatic from non-traumatic intracranial subdural hemorrhage. Cervical MRI should be considered in children with acute intracranial bleeds and otherwise non-contributory history, physical examination and ophthalmological findings. There is a statistically significant relationship between diffuse hypoxic-ischemic brain injury patterns and abusive head trauma. The high incidence of cervical injuries in children with hypoxic-ischemic injuries suggests a causal relationship. Overall, increased utilization of brain and spine MRI in children being evaluated for abusive head trauma can be helpful.

Prevalence and relevance of pediatric spinal fractures in suspected child abuse

BACKGROUND

Spinal fractures are uncommon manifestations of child abuse and elimination of the lateral views of the spine from the initial skeletal survey protocol has been recommended.

OBJECTIVE

To establish the prevalence of spinal fractures detected on skeletal surveys performed for suspected child abuse and their association with intracranial injury (ICI).

MATERIALS AND METHODS

The ACR standardized skeletal surveys and neuroimaging studies of 751 children (ages 0-4 years) were reviewed. A positive skeletal survey was defined as having one or more clinically unsuspected fractures.

RESULTS

Fourteen children had a total of 22 definite spinal fractures. This constituted 1.9% (14/751) of the total cohort, and 9.7% (14/145) of children with a positive skeletal survey. Advanced imaging confirmed the fractures in 13 of the 14 children and demonstrated 12 additional spinal fractures. In five cases, spinal fractures were the only positive skeletal findings. In 71% (10/14) of the children, the spinal fractures were accompanied by ICI. Children with spinal fractures were at significantly greater risk for ICI than those without spinal injury (P < 0.05).

CONCLUSION

Spinal fractures are not rare in children with positive skeletal surveys performed for suspected abuse and they may be the only indication of skeletal trauma. There is an association between spinal fractures and ICI.

Spinal subdural hemorrhage in abusive head trauma: a retrospective study

PURPOSE

To compare the relative incidence, distribution, and radiologic characteristics of spinal subdural hemorrhage after abusive head trauma versus that after accidental trauma in children.

MATERIALS AND METHODS

This study received prior approval from the Human Subjects Protection Office. Informed consent was waived. This study was HIPAA compliant. Two hundred fifty-two children aged 0-2 years treated for abusive head trauma at our institute between 1997 and 2009 were identified through retrospective chart review. A second group of 70 children aged 0-2 years treated at our institute for well-documented accidental trauma between 2003 and 2010 were also identified through retrospective chart review. All clinical data and cross-sectional imaging results, including computed tomographic and magnetic resonance imaging of the brain, spine, chest, abdomen, and pelvis, were reviewed for both of these groups. A Fisher exact test was performed to assess the statistical significance of the proportion of the spinal canal subdural hemorrhage in abusive head trauma versus that in accidental trauma.

RESULTS

In the abusive head trauma cohort, 67 (26.5%) of 252 children had evaluable spinal imaging results. Of these, 38 (56%) of 67 children had undergone thoracolumbar imaging, and 24 (63%) of 38 had thoracolumbar subdural hemorrhage. Spinal imaging was performed in this cohort 0.3-141 hours after injury (mean, 23 hours ± 27 [standard deviation]), with 65 (97%) of 67 cases having undergone imaging within 52 hours of injury. In the second cohort with accidental injury, only one (1%) of 70 children had spinal subdural hemorrhage at presentation; this patient had displaced occipital fracture. The comparison of incidences of spinal subdural hemorrhage in abusive head trauma versus those in accidental trauma was statistically significant (P < .001).

CONCLUSION

Spinal canal subdural hemorrhage was present in more than 60% of children with abusive head trauma who underwent thoracolumbar imaging in this series but was rare in those with accidental trauma.

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.

The encephalopathic child

Encephalopathy is a common paediatric emergency associated with a high risk of morbidity, mortality and long term neurodevelopmental delay in survivors. Prompt diagnosis of the cause of encephalopathy enables the paediatrician to deliver specific medical or surgical treatment that will facilitate a better short and long term outcome. Diagnostic imaging plays a pivotal role in diagnosis. Encephalopathy has many causes. The differential diagnosis includes non accidental injury, trauma, metabolic syndromes, meningo-encephalitis, toxins, hypoxia, demyelination, stroke, haemorrhage and tumours. We describe an approach that helps us formulate an imaging strategy using US, CT and MRI that facilitates patient care.

Lumbar intraspinal arachnoid cyst superimposed by hyperacute spinal subdural hematoma: an unusual case

BACKGROUND CONTEXT

Lumbar intradural arachnoid cyst (AC) concomitant with hyperacute spinal subdural hematoma (SSDH) has never been reported in the literature.

PURPOSE

To report a case of lumbar AC superimposed by hyperacute SSDH, which was difficult to diagnose preoperatively using magnetic resonance imaging. Herein, we describe diagrams showing the proposed mechanisms underlying the formation of a symptomatic AC.

STUDY DESIGN/SETTING

The study was designed to be a case report and literature review.

METHODS

A 65-year-old man presented with acute onset of low back pain, followed by 5-day history of numbness and weakness in both legs before admission. Magnetic resonance imaging of the lumbosacral spine revealed an intradural extramedullary biconvex lesion at the L3-L4 level; the lesion compressed the cauda equina posteriorly. The lesion mainly appeared as hyperintense on T2-weighted images and hypointense on T1-weighted images. On the basis of these findings, the lesion was preoperatively diagnosed as a symptomatic lumbar subdural AC that compressed the cauda equina.

RESULTS

The patient underwent laminectomy from L2 to L4. After a dura incision, a partially organized subdural hematoma was noted. Beneath the subdural hematoma was an AC compressing the underlying nerve roots. The patient's back pain and muscle strength markedly improved after the operation.

CONCLUSIONS

Preoperative diagnosis of concomitant hyperacute SSDH and AC is difficult. In cases of patients who present with intraspinal AC accompanied by an acute onset of clinical presentation, an associated etiology should be considered until proven otherwise.

Do cranial subdural hematomas migrate to the lumbar spine?

We report a patient with minor head trauma-related bilateral hemispheric subdural hematoma (SDH) and subsequent delayed spinal SDH or presumed migration to the lumbar spine. An acutely confused 88-year-old man presented to the Emergency Department after minor head trauma. Head CT scan revealed a small hemispheric SDH. The patient was admitted for observation. CT scan 6 hours later showed bilateral SDH with extension to the tentorium. Three days later SDH had resolved leaving bilateral subdural hygromas. Local leg weakness localized to the lumbar spine developed on day 6; spinal CT scan and MRI revealed a posterior L5-S1 collection. A pure subacute subdural hematoma compressing the cauda equina was drained after an L5 laminectomy. His lower leg weakness improved. The patient was discharged to rehabilitation two weeks after surgery. Patients with traumatic SDH who develop late-onset neurological deterioration attributable to any region of the spine should be evaluated for spinal SDH.

Neuroimaging of abusive head trauma

The diagnostic process for evaluating suspected abusive head trauma in infants and children has evolved with technological advances in neuroimaging. Since Caffey first described a series of children with chronic subdural hematomas and multiple long bone fractures, radiologists have played an important role, along with pediatricians and pathologists, in evaluating abused children. Neuroimaging modalities include ultrasound, CT scans, and MRI technology. Each has distinct clinical applications, as well as practical uses in the clinical diagnostic process of AHT. Importantly, neuroimaging assists in the process of differential diagnosis of other conditions which may mimic AHT. Collaboration between neuroradiologists, clinicians, and pathologists remains critical to making the appropriate diagnosis. Careful history, physical examination, and investigation by legal authorities form the components that result in accurate assessment of any case. This paper reviews pertinent neuroimaging modalities currently utilized in the diagnosis of AHT, describing clinical indications and a collaborative approach to this process.