Spinal injuries in abusive head trauma: patterns and recommendations

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.

A Biomechanical Assessment of Shaken Baby Syndrome: What About the Spine?

BACKGROUND

Shaken baby syndrome occurs following inertial loading of the pediatric head, resulting in retinal hemorrhaging, subdural hematoma, and encephalopathy. However, the anatomically vulnerable cervical spine receives little attention. Automotive safety literature is replete with biomechanical data involving forward-facing pediatric surrogates in frontal collisions, an environment analogous to shaking. Publicly available data involving child occupants were utilized to study pediatric neck and head injury potential. We hypothesized that inertial loading provides a greater risk of injury to the cervical spine than to the head.

METHODS

Full-scale automotive crash tests (n = 131) and deceleration sled tests (n = 32) utilizing forward-facing 3-year-old surrogates with head accelerometers and cervical force sensors were analyzed. One hundred sixty-seven full-scale vehicle and 33 sled test runs were assessed in the context of published injury assessment reference values (IARVs) for closed head injury (head injury criterion 15 [HIC₁₅]) and cervical tensile strength in the 3-year-old model.

RESULTS

One hundred sixty-one (96%) child surrogates in full-scale crash tests exceeded the cervical peak tension IARV, while only 37 (22%) surpassed the HIC₁₅ IARV. Similarly, in sled testing runs, 27 (82%) pediatric surrogates exceeded cervical tension IARVs, while 1 (3%) surpassed the HIC₁₅ IARV. In both full-scale and sled tests, all surrogates surpassing the HIC₁₅ IARV also exceeded the cervical tension IARV. Positive linear correlations were observed between HIC₁₅ and cervical tensile forces in both full-scale vehicle (R² = 0.15) and sled testing runs (R² = 0.54).

CONCLUSIONS

These data support the hypothesis that inertial loading of the head provides a greater injury risk to the cervical spine than to closed-head injury.

Whole-Spine MRI in Children With Suspected Abusive Head Trauma

BACKGROUND. Abusive head trauma (AHT) in children has recently been associated with findings on cervical spine MRI. OBJECTIVE. The purpose of this study was to evaluate whether whole-spine MRI in children with suspected AHT shows additional abnormalities not identified on cervical spine MRI. METHODS. This retrospective study included 256 children younger than 3 years old (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 a 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. Interobserver 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 of 256 (57.8%) children underwent whole-spine MRI. AHT was diagnosed in 79 of 148 (53.4%) children who underwent whole-spine MRI versus in 2 of 108 (1.9%) who did not undergo whole-spine MRI (p < .001). Interobserver agreement, expressed as kappa coefficient, 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 of 148 (38.5%) whole-spine MRI examinations showed injuries, and 34 of 148 (23.0%) showed injuries localized to the thoracolumbar spine. A total of 47 of 148 (31.8%) whole-spine MRI examinations showed major findings, of which 24 (51.1%) were localized to the thoracolumbar spine. Isolated thoracolumbar injuries included 23 of 34 spinal subdural hematomas, 2 of 3 spinal epidural hematomas, and 9 of 11 vertebral fractures, including five 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 shows isolated thoracolumbar injuries. CLINICAL IMPACT. The results support performing whole-spine MRI rather than cervical spine MRI in children with suspected AHT.

Abusive head trauma in India: imaging raises the curtain

The purpose of the study was to identify children at our institute who possibly suffered abusive head trauma (AHT). A retrospective study of CT imaging of children between one month to three years of age between January 2013 and May 2021 was carried out at a dedicated neurocentre in Southern India. We identified 48 cases of possible AHT. The demographics, clinical features at presentation, imaging and fundus findings were analyzed. Imaging revealed subdural hemorrhage (SDH) in 42 and sub dural effusion (SDE) in 5 cases, one case had only hypoxia. The location of SDH was studied as was hypoxia underlying SDH, global hypoxia and ischemia. Cases of subarachnoid hemorrhage (SAH), parenchymal hematoma & intraventricular hemorrhage (IVH) were also noted. Skeletal survey, chest X-ray and CT spine were reviewed. AHT needs to be paid attention to in the Indian scenario. An extensive work up is required to substantiate the claim and to work on prevention & management of these cases subsequently.

Whole-body MR imaging in suspected physical child abuse: comparison with skeletal survey and bone scintigraphy findings from the PEDIMA prospective multicentre study

OBJECTIVES

To assess the contribution of whole-body magnetic resonance imaging (WBMRI) and bone scintigraphy (BS) in addition to skeletal survey (SS) in detecting traumatic bone lesions and soft-tissue injuries in suspected child abuse.

METHODS

In this prospective, multicentre, diagnostic accuracy study, children less than 3 years of age with suspected physical abuse were recruited. Each child underwent SS, BS and WBMRI. A blinded first review was performed in consensus by five paediatric radiologists and three nuclear medicine physicians. A second review investigated discrepancies reported between the modalities using a consensus result of all modalities as the reference standard. We calculated the sensitivity, specificity and corresponding 95% confidence interval for each imaging modality (SS, WBMRI and BS) and for the combinations [SS + WBMRI] and [SS + BS].

RESULTS

One hundred seventy children were included of which sixty-four had at least one lesion. In total, 146 lesions were included. The sensitivity and specificity of each examination were, respectively, as follows: 88.4% [95% CI, 82.0-93.1] and 99.7% [95% CI, 99.5-99.8] for the SS, 69.9% [95% CI, 61.7-77.2] and 99.5% [95% CI, 99.2-99.7] for WBMRI and 54.8% [95% CI, 46.4-63.0] and 99.7% [95% CI, 99.5-99.9] for BS. Sensitivity and specificity were, respectively, 95.9% [95% CI, 91.3-98.5] and 99.2% [95% CI, 98.9-99.4] for the combination SS + WBMRI and 95.2% [95% CI, 90.4-98.1] and 99.4% [95% CI, 99.2-99.6] for the combination SS + BS, with no statistically significant difference between them.

CONCLUSION

SS was the most sensitive independent imaging modality; however, the additional combination of either WBMRI or BS examinations offered an increased accuracy.

KEY POINTS

• SS in suspected infant abuse was the most sensitive independent imaging modality in this study, especially for detecting metaphyseal and rib lesions, and remains essential for evaluation. • The combination of either SS + BS or SS + WBMRI provides greater accuracy in diagnosing occult and equivocal bone injuries in the difficult setting of child abuse. • WBMRI is a free-radiation technique that allows additional diagnosis of soft-tissue and visceral injuries.

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.

Characteristics associated with spine injury on magnetic resonance imaging in children evaluated for abusive head trauma

BACKGROUND

Spine injuries are increasingly common in the evaluation for abusive head trauma (AHT), but additional information is needed to explore the utility of spine MRI in AHT evaluations and to ensure an accurate understanding of injury mechanism.

OBJECTIVE

To assess the incidence of spine injury on MRI in children evaluated for AHT, and to correlate spine MRI findings with clinical characteristics.

MATERIALS AND METHODS

We identified children younger than 5 years who were evaluated for AHT with spine MRI. Abuse likelihood was determined a priori by expert consensus. We blindly reviewed spine MRIs and compared spinal injury, abuse likelihood, patient demographics, severity of brain injury, presence of retinal hemorrhages, and pattern of head injury between children with and without spine injury.

RESULTS

Forty-five of 76 (59.2%) children had spine injury. Spine injury was associated with more severe injury (longer intensive care stays [P<0.001], lower initial mental status [P=0.01] and longer ventilation times [P=0.001]). Overall abuse likelihood and spine injury were not associated. Spinal subdural hemorrhage was the only finding associated with a combination of retinal hemorrhages (P=0.01), noncontact head injuries (P=0.008) and a diagnosis of AHT (P<0.05). Spinal subdural hemorrhage was associated with other spine injury (P=0.004) but not with intracranial hemorrhage (P=0.28).

CONCLUSION

Spinal injury is seen in most children evaluated for AHT and might be clinically and forensically valuable. Spinal subdural hemorrhage might support a mechanism of severe acceleration/deceleration head injury and a diagnosis of AHT.

Diagnostic Imaging for Physical Abuse in Children

신체적 학대로 인한 손상은 소아에서 이환율과 사망률의 중요한 원인이 된다. 특히, 1세 이하의 영아가 신체적 학대의 위험이 높다. 신체적 학대가 의심되는 경우 영상의학과 의사의 역할은 매우 중요한데 학대가 의심되는 영상의학적 소견을 찾고 다른 질환과의 감별을 통해 신속하고 정확한 진단을 내려야 한다. 본 논문에서는 신체적 학대를 받은 아동에서 흔히 보일 수 있는 특징적인 손상인 골절, 머리 손상, 척추 손상, 흉부와 복부의 손상 등의 여러 영상의학적 소견을 설명하고 이러한 손상이 유발되는 생체 역학적 힘의 기전에 대해 알아보고자 한다.

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.

Modern post-mortem imaging: an update on recent developments

Modern post-mortem investigations use an increasing number of digital imaging methods, which can be collected under the term "post-mortem imaging". Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging. To digitally image the surface of the body, other techniques are regularly applied, e.g. three-dimensional (3D) surface scanning (3DSS) or photogrammetry. Today's most frequently used techniques include post-mortem computed tomography (PMCT), post-mortem magnetic resonance imaging (PMMR), post-mortem computed tomographic angiography (PMCTA) and 3DSS or photogrammetry. Each of these methods has specific advantages and limitations. Therefore, the indications for using each method are different. While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies, PMMR allows investigation of soft tissues and parenchymal organs. PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding. However, none of those radiological methods allow a detailed digital view of the body's surface, which makes 3DSS the best choice for such a purpose. If 3D surface scanners are not available, photogrammetry is an alternative. This review article gives an overview of different imaging techniques and explains their applications, advantages and limitations. We hope it will improve understanding of the methods.

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.

Imaging of Abusive Trauma

"Shaken baby syndrome" is a term often used by the physicians and public to describe abusive trauma inflicted on infants and young children. Advances in the understanding of the mechanisms and the associated clinical spectrum of injury has lead us to modify our terminology and address it as "abusive trauma" (AT). Pediatric abusive head trauma is defined as an injury to the skull or intracranial contents of an infant or a young child (< 5 y age) due to inflicted blunt impact and/or violent shaking. This chapter focuses on the imaging aspects of childhood abusive trauma along with a brief description of the mechanism and pathophysiology of abusive injury. The diagnosis of AT is not always obvious, and abusive injuries in many infants may remain unrecognized. Pediatricians should be cognizant of AT since pediatricians play a crucial role in the diagnosis, management and prevention of AT.

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.

Magnetic Resonance Imaging of Pediatric Neurologic Emergencies

Although computed tomography is often the first line of imaging in the emergency setting, magnetic resonance imaging (MRI) is of increasing importance in the evaluation of central nervous system emergencies in the pediatric population. As such, it is necessary to understand the indications for which MRI may be necessary. This article reviews the unique pathophysiologic entities affecting the pediatric population and the associated MRI findings. Specifically, utility of emergent MRI and characteristic appearances of traumatic brain injury, traumatic spinal injury, nonaccidental trauma, arterial ischemic stroke, cerebral sinovenous thrombosis, stroke mimics, and central nervous system infections are described.

Diffusion tensor imaging of the cervical spinal cord in children

PURPOSE

Obtaining fast, reliable, high-resolution diffusion tensor imaging (DTI) of the pediatric cervical spinal cord (CSC) is challenging, given the multitude of technical limitations involved. Overcoming these limitations may further potentiate DTI as a valuable quantitative tool in evaluating the pediatric CSC.

METHODS

Sixteen patients (9 girls and 7 boys) with hypoxic brain injury, craniocervical junction malformations, and head trauma were included in this retrospective study. Region of interests were placed from C1-C2 through C7-T1 consecutively at the cervical intervertebral disc levels. DTI metrics were compared with a pediatric DTI database of healthy controls. Clinical background and outcomes were tabulated.

RESULTS

Patients with hypoxic brain injury, Chiari I and II malformations, and head trauma demonstrated lower fractional anisotropy values than that of healthy controls at certain cervical intervertebral disc levels.

CONCLUSIONS

DTI may be a promising modality for providing additional information beyond that of conventional magnetic resonance imaging in pediatric central nervous system disorders.