Nonaccidental head injury in infants: "the shaken baby syndrome revisited"

Predictive value of early radiological findings in inflicted traumatic brain injury

AIM

The aim of this study was to evaluate the value of early radiological investigations in predicting the long-term neurodevelopmental outcome of patients with inflicted traumatic brain injury (ITBI).

METHODS

In 28 patients with ITBI, radiological investigations were performed during the acute phase of injury (0-3 days) and during the early post-injury phase (4 days to 1 month). The clinical outcome in survivors (n = 24) was based on the Glasgow Outcome Score.

RESULTS

Four of 28 infants died and five were severely disabled. Six infants had moderate disability. Detection of changes in the basal ganglia (p < 0.000005) or brainstem (p < 0.01), diffuse oedema (p < 0.005), transtentorial herniation (p < 0.01), subarachnoid haemorrhage (p < 0.05) or parenchymal injury (p < 0.05) by neuroimaging during the first 3 days, and detection of changes in the basal ganglia (p < 0.0005) or brainstem (p < 0.05) or parenchymal injury (p < 0.01) during 1 month were significantly associated with poor long-term outcome.

CONCLUSION

Radiological findings during the first month were significantly associated with the long-term outcome. Especially, basal ganglia lesions were associated with a poor outcome.

An overview of inflicted head injury in infants and young children, with a review of beta-amyloid precursor protein immunohistochemistry

CONTEXT

Inflicted traumatic brain injury of infants and young children results in a complex array of autopsy findings. In many cases, immunostains for beta-amyloid precursor protein are used to detect axonal injury. Interpretation of the gross, microscopic, and immunostaining results requires the integration of the many facets of the individual case.

OBJECTIVE

In this article we review the gross and microscopic findings associated with inflicted traumatic brain injury. The application and interpretation of beta-amyloid precursor protein immunostains are discussed and photomicrographs are used to illustrate immunostaining patterns.

DATA SOURCES

The pertinent literature is integrated into a review of the subject.

CONCLUSIONS

Inflicted traumatic brain injury often results in subdural, subarachnoid, retinal, and optic nerve sheath hemorrhage. These findings must be interpreted within the entire context of the case. Beta-amyloid precursor protein immunostains may be helpful in illustrating the traumatic nature of the injuries in some cases.

Delayed white matter injury in a murine model of shaken baby syndrome

Shaken baby syndrome, a rotational acceleration injury, is most common between 3 and 6 months of age and causes death in about 10 to 40% of cases and permanent neurological abnormalities in survivors. We developed a mouse model of shaken baby syndrome to investigate the pathophysiological mechanisms underlying the brain damage. Eight-day-old mouse pups were shaken for 15 seconds on a rotating shaker. Animals were sacrificed at different ages after shaking and brains were processed for histology. In 31-day-old pups, mortality was 27%, and 75% of survivors had focal brain lesions consisting of hemorrhagic or cystic lesions of the periventricular white matter, corpus callosum, and brainstem and cerebellar white matter. Hemorrhagic lesions were evident from postnatal day 13, and cysts developed gradually between days 15 and 31. All shaken animals, with or without focal lesions, had thinning of the hemispheric white matter, which was significant on day 31 but not earlier. Fragmented DNA labeling revealed a significant increase in cell death in the periventricular white matter, on days 9 and 13. White matter damage was reduced by pre-treatment with the NMDA receptor antagonist MK-801. This study showed that shaking immature mice produced white matter injury mimicking several aspects of human shaken baby syndrome and provided evidence that excess release of glutamate plays a role in the pathophysiology of the lesions.

Rigid-body modelling of shaken baby syndrome

Recent reassessment of the literature on the shaken baby syndrome (SBS) has revealed a lack of scientific evidence and understanding of all aspects of the syndrome. In particular, studies have been unable to clarify the mechanisms of injury, indicating that impact, rather than shaking alone, is necessary to cause the type of brain damage observed. Rigid-body modelling (RBM) was used to investigate the effect of neck stiffness on head motion and head-torso impacts as a possible mechanism of injury. Realistic shaking data obtained from an anthropometric test dummy (ATD) was used to simulate shaking. In each study injury levels for concussion were exceeded, though impact-type characteristics were required to do so in the neck stiffness study. Levels for the type of injury associated with the syndrome were not exceeded. It is unlikely that further gross biomechanical investigation of the syndrome will be able to significantly contribute to the understanding of SBS. Current injury criteria are based on high-energy, single-impact studies. Since this is not the type of loading in SBS it is suggested that their application here is inappropriate and that future studies should focus on injury mechanisms in low-energy cyclic loading.

The mechanism of injury of the abducens nerve in severe head trauma: a postmortem study

The aim of this study is to investigate the mechanism of injury of abducens nerve at petroclival region in severe head trauma. Twenty specimens provided from 10 autopsied cases due to severe head trauma were investigated macroscopically and histopathogically. The slices of the abducens nerve taken consecutively along its course at petroclival region were stained with Hematoxylline-Eosin and evaluated under light microscope. In addition, coexisting cervical injuries in these cases were assessed macroscopically. Edema and perineural hemorrhagia of abducens nerve were identified in all cases. Nerve injury was found more exaggerated at the sites of dural entry point and petrous apex than any other parts of the abducens nerve. Furthermore, microscopically, also remarkable perineural hemorrhage of the abducens nerve was observed at the site of its anastomoses with the sympathetic plexus on the lateral wall of the internal carotid artery (ICA). Abducens nerve is injured at the sites of dural entry point, petrous apex and lateral wall of the ICA, directly proportional with the severity of the trauma. This finding is also significant in verification of the severe head trauma.

Neuroimaging of intraparenchymal lesions predicts outcome in shaken baby syndrome

OBJECTIVE

Studies of long-term outcome on nonaccidental head injury (NAHI) in young children have shown severe neurodevelopmental sequelae in most cases. For improving the knowledge of outcome and for identifying prognostic factors, additional clinical and cerebral imaging data are needed. The aim of this study was to describe clinical and imaging features over time and to consider their value for predicting neurodevelopmental outcome.

METHODS

A retrospective medical record review was conducted of 23 children with confirmed NAHI, for whom an extended follow-up of 2.5 to 13 years (mean: 6 years) was contemplated. Glasgow Coma Scale scores, severity of retinal hemorrhages, presence of skull fractures, cranial growth deceleration, and sequential neuroimaging data (computed tomography and/or magnetic resonance imaging) were compared with patterns of clinical evolution assessed by the Glasgow Outcome Scale.

RESULTS

Clinical outcome showed that 14 (61%) children had severe disabilities, 8 (35%) had moderate disabilities, and 1 (4%) was normal. A low initial Glasgow Coma Scale score, severe retinal hemorrhages, presence of skull fracture, and cranial growth deceleration were significantly associated with poor developmental outcome. Eighteen of the 23 patients had abnormal magnetic resonance imaging scans. This examination disclosed atrophy when performed beyond 15 days of injury. Atrophy seemingly resulted from various brain lesions, namely, contusions, infarcts, and other lesions within the white matter. Presence of intraparenchymal brain lesions within the first 3 months was significantly associated with neurodevelopmental impairment. Severity of motor and cognitive dysfunctions was related to the extent of intraparenchymal lesions.

CONCLUSIONS

Early clinical and radiologic findings in NAHI are of prognostic value for neurodevelopmental outcome.

From the archives of the AFIP. Child abuse: radiologic-pathologic correlation

In the United States, roughly one of every 100 children is subjected to some form of neglect or abuse; inflicted injury is responsible for approximately 1,200 deaths per year. Child physical abuse may manifest as virtually any injury pattern known to medicine. Some of the injuries observed in battered children are relatively unique to this population (especially when observed in infants) and therefore are highly suggestive of nonaccidental, or inflicted, injury. Worrisome injuries include rib fracture, metaphyseal fracture, interhemispheric extraaxial hemorrhage, shear-type brain injury, vertebral compression fracture, and small bowel hematoma and laceration. As noted, however, virtually any injury may be inflicted; therefore, careful consideration of the nature of the injury, the developmental capabilities of the child, and the given history are crucial to determine the likelihood that an injury was inflicted. The majority of these injuries are readily detectable at imaging, and radiologic examination forms the mainstay of evaluation of child physical abuse. Detection of metaphyseal fracture (regarded as the most specific radiographically detectable injury in abuse) depends on high-quality, small field-of-view radiographs. The injury manifests radiographically as a lucent area within the subphyseal metaphysis, extending completely or partially across the metaphysis, roughly perpendicular to the long axis of the bone. Acute rib fractures (which in infants are strongly correlated with abuse) appear as linear lucent areas. They may be difficult to discern when acute; thus, follow-up radiography increases detection of these fractures. For skull injuries, radiography is best for detecting fractures, but computed tomography and magnetic resonance imaging best depict intracranial injury.

Child abuse in the pediatric intensive care unit

Critically ill and injured children due to abusive or inflicted injury represent a growing challenge for pediatric intensive care unit personnel in terms of the number of patients seen each year in the United States and the intellectual and emotional response required to deal with this tragic problem. We present a distillation of the current knowledge of childhood physical abuse with a focus on the child with inflicted injury who is admitted to the pediatric intensive care unit. In addition to a discussion of the epidemiology, clinical presentation, an approach to diagnosis, and treatment strategies, we also explore the legal issues that confront pediatric intensive care unit physicians in relation to determination of brain death, suitability of victims for organ donation, and the physician's role in the criminal investigation of child abuse and as a witness for court proceedings.

Outcomes of child abuse

The limited research available regarding the outcome of inflicted TBI suggests that this type of injury may be especially deleterious to infants and young children. It is likely that mechanisms of injury, age at injury, and circumstances of injury (i.e., child abuse and maltreatment) all contribute to these findings. Until recently, the investigations of TBI and child abuse and maltreatment have occurred on two separate tracks. The review of these two literatures indicates that the TBI outcome literature is strongly grounded in neuropsychologic methodology, whereas the child abuse and maltreatment literature depends most heavily on less brain-specific measures of general intellectual ability and academic achievement. The evidence reviewed here suggests that it is time for these areas of research to converge. Children with inflicted head injury should be evaluated not only to assess outcome related to TBI but to disconfirm the presence of PTSD, a developmental disorder that may also result in CNS changes. In this vulnerable population, longitudinal assessment well past the period of initial insult is imperative to assess the rate of development of skills, to identify deficient areas, and to plan appropriate interventions.

Diffusion-weighted magnetic resonance imaging in Shaken Baby Syndrome

PURPOSE

To evaluate the role of diffusion-weighted magnetic resonance imaging (DWIMRI) in the diagnosis and management of children with suspected or confirmed Shaken Baby Syndrome (SBS).

METHODS

This was a retrospective interventional case series of all infants and children younger than 2 years of age admitted to a children's hospital. We retrospectively reviewed medical records and neuroimaging findings of all children younger than 2 years of age with confirmed or suspected SBS admitted to a children's hospital. Inclusion criteria were documented ocular examination by an ophthalmologist and a brain MRI with DWI. Twenty-six infants and children were included. Other children were excluded. Children with proven SBS were diagnosed with "confirmed SBS," while children in whom the diagnosis of SBS remained uncertain were diagnosed with "suspected SBS."

RESULTS

Twenty-six infants and children with mean age of 7.1 months (range, 6 weeks-24 months) were included, 18 with confirmed SBS. All 26 patients had a subdural hematoma, 10 had associated occult bone fractures, and 18 had retinal hemorrhages. Seven of the eight cases without retinal hemorrhages had isolated subdural hematoma without parenchymal brain lesions on both conventional MRI and DWIMRI. SBS was confirmed in only one case with a normal fundus. Among the 18 patients with retinal hemorrhages, SBS was confirmed in all but one case. All 18 patients with confirmed SBS had an abnormal DWIMRI. In 13 patients, DWI showed lesions that were larger than on conventional MRI. In patients with brain parenchymal lesions, the DWIMRI characteristics suggested cerebral ischemia, which appears to play a major role in SBS.

CONCLUSIONS

In all patients with confirmed SBS, DWIMRI was abnormal and suggested diffuse or posterior cerebral ischemia, in addition to subdural hematomas in the pathogenesis of this disorder.