Anatomy of the shaken baby syndrome

Repetitive Traumatic Brain Injury Is Associated With TDP-43 Alterations, Neurodegeneration, and Glial Activation in Mice

Increasing evidence points to a relationship between repetitive mild traumatic brain injury (mTBI), the Tar DNA binding protein 43 (TDP-43) pathology and some neurodegenerative diseases, but the underlying pathophysiological mechanisms are still unknown. We examined TDP-43 regulation, neurodegeneration, and glial responses following repetitive mTBI in nontransgenic mice and in animals with overexpression of human mutant TDP-43 protein (TDP-43G348C). In the frontal cortices of the injured nontransgenic animals, early TDP-43 cytoplasmatic translocation and overexpression of the protein and its pathological forms were detected. In the injured animals of both genotypes, neurodegeneration and pronounced glial activity were detected in the optic tract. In TDP-43G348C mice, these changes were significantly higher at day 7 after the last mTBI compared with the values in the nontransgenic animals. Results of this study suggest that the changes in the TDP-43 regulation in the frontal cortices of the nontransgenic animals were a transient stress response to the brain injury. Repetitive mTBI did not produce additional TDP-43 dysregulation or neurodegeneration or pronounced gliosis in the frontal cortex of TDP-43G348C mice. Our research also suggests that overexpression of mutated human TDP-43 possibly predisposes the brain to more intense neurodegeneration and glial activation in the optic tract after repetitive mTBI.

Long-Term Effects of Repetitive Mild Traumatic Injury on the Visual System in Wild-Type and TDP-43 Transgenic Mice

Little is known about the impairments and pathological changes in the visual system in mild brain trauma, especially repetitive mild traumatic brain injury (mTBI). The goal of this study was to examine and compare the effects of repeated head impacts on the neurodegeneration, axonal integrity, and glial activity in the optic tract (OT), as well as on neuronal preservation, glial responses, and synaptic organization in the lateral geniculate nucleus (LGN) and superior colliculus (SC), in wild-type mice and transgenic animals with overexpression of human TDP-43 mutant protein (TDP-43^G348C) at 6 months after repeated closed head traumas. Animals were also assessed in the Barnes maze (BM) task. Neurodegeneration, axonal injury, and gliosis were detected in the OT of the injured animals of both genotypes. In the traumatized mice, myelination of surviving axons was mostly preserved, and the expression of neurofilament light chain was unaffected. Repetitive mTBI did not induce changes in the LGN and the SC, nor did it affect the performance of the BM task in the traumatized wild-type and TDP-43 transgenic mice. Differences in neuropathological and behavioral assessments between the injured wild-type and TDP-43^G348C mice were not revealed. Results of the current study suggest that repetitive mTBI was associated with chronic damage and inflammation in the OT in wild-type and TDP-43^G348C mice, which were not accompanied with behavioral problems and were not affected by the TDP-43 genotype, while the LGN and the SC remained preserved in the used experimental conditions.

Acute Subdural Hematoma in Infants with Abusive Head Trauma: A Literature Review

The number of cases with child abuse is increasing in Japan, and abusive head trauma (AHT) is a major cause of death in abused children. Child abuse has been recognized by the late 19th century, and widely accepted as battered child syndrome in the middle of the 20th century. As terms, there had been considerable mechanistic controversies between shaken-baby and -impact syndrome until the beginning of the 21st century. In recent years, AHT has been utilized as a less mechanistic term. Most of the characteristics of AHT in Japan have been similar to those in the United States as follows: infant is the most common victim, acute subdural hematoma (SDH) is the most common intracranial lesion, and retinal hemorrhage is often complicated. On the other hand, several characteristics have been different as follows: mother is the most common perpetrators, impact is a more common mechanism of trauma than shaking, and external trauma is more common reflecting the existence of impact. Since AHT as well as child abuse is a social pathological phenomenon influenced by victims, perpetrators, socioeconomic circumstances, and so on, various aspects of AHT as well as child abuse can be changed with times. Actually, a recent paper suggests such changes in infants with acute SDH due to AHT. In this review article, AHT, abusive infantile acute SDH in particular, are reviewed from the aspect of neurosurgical perspectives, including its mechanisms of trauma, biomechanics, clinical features, management, and prognosis, to update the trend in Japan.

Neuroimaging differential diagnoses to abusive head trauma

Trauma is the most common cause of death in childhood, and abusive head trauma is the most common cause of traumatic death and morbidity in infants younger than 1 year. The main differential diagnosis of abusive head trauma is accidental traumatic brain injury, which is usually witnessed. This paper also discusses more uncommon diagnoses such as congenital and acquired disorders of hemostasis, cerebral arteriovenous malformations and metabolic diseases, all of which are extremely rare. Diagnostic imaging including CT and MRI is very important for the distinction of non-accidental from accidental traumatic injury.

β-Amyloid Precursor Protein and Ubiquitin Immunohistochemistry Aid in the Evaluation of Infant Autopsy Eyes With Abusive Head Trauma

PURPOSE

To investigate β-amyloid precursor protein (β-APP), ubiquitin, and glial fibrillary acid protein (GFAP) immunostaining as a diagnostic tool to aid in the discrimination between abusive head trauma and nonabusive head trauma in postmortem ocular histopathologic investigation.

DESIGN

Retrospective cross-sectional study.

METHODS

Seventy-four eyes of 37 infants were studied for hemorrhage and immunohistochemical expression of β-APP, ubiquitin, and GFAP in the retina and optic nerve. Infants were assigned to abusive head trauma or control groups, according to published criteria.

RESULTS

In the abusive head trauma group, positive β-APP and ubiquitin immunostaining of the retina was significantly more likely to be found than in the control group, odds ratio (OR) 11.4, confidence interval (CI) 2.9-44.3; P < .001 and OR 8.8, CI 2.2-34.5; P = .002, respectively. Positive correlations were found between retinal expression of β-APP and ubiquitin immunostaining and retinal hemorrhage. Vitreal hemorrhages, orbital fat hemorrhages, and macular folds could only be identified in abusive head trauma cases. Retinal hemorrhages were significantly more severe, occupied a larger proportion of the retina, and involved more retinal layers in abusive head trauma compared to controls (OR 2.7, CI 1.7-4.4; P < .001).

CONCLUSIONS

This study shows correlations between positive retinal β-APP and ubiquitin immunostaining as a sign of axonal injury in abusive head trauma. Axonal injury is a useful pathologic feature that can be demonstrated in postmortem ocular investigation of deceased children using immunohistochemical staining for β-APP and ubiquitin with a high OR for abusive head trauma when compared to controls.

A brief history of fatal child maltreatment and neglect

Child abuse encompasses four major forms of abuse: physical abuse, sexual abuse, psychological abuse, and neglect. The United States retains one of the worst records of child abuse in the industrialized world. It has also been determined that a large portion of these cases are missed and go undocumented in state and federal reporting agencies. In addition, disparate risk factors have been identified for physical abuse and neglect cases, but substance abuse has been found to be a significant factor in all forms of abuse. Fatal child maltreatment and neglect investigations require a multi-pronged and multidisciplinary approach requiring the coordination and information gathering from various agencies. A major difficulty in determining the accidental or non-accidental nature of these cases is that the account surrounding the events of the death of child is acquired from the caretaker. In this review, we outline common diagnostic characteristics and patterns of non-accidental injuries and neglect as a result of nutritional deprivation.

Abusive head trauma: A perpetrator confesses

OBJECTIVES

To present a detailed confession from a perpetrator of Shaken Baby syndrome.

METHODS

Case study.

RESULTS

We present a confession of Shaken Baby syndrome describing how the perpetrator severely injured a 3 year old with repeated bursts of acceleration-deceleration (shaking). The child sustained retinal and intracranial hemorrhage. Details of the confession and circumstances by which it was obtained lead us to believe its accuracy.

CONCLUSIONS

Accurate perpetrator confessions offer useful windows into realities and pathophysiology of abusive head trauma.

Transmission of whole body vibration in children while standing

BACKGROUND

Whole body vibration has recently been used as a therapeutic intervention for the treatment of children with disabling conditions. Researchers of these studies observed encouraging results; however, children may not be capable of attenuating high vibration accelerations to the head because of low mass. The purpose of this study was to determine if children transmit vibration differently than adults while standing on a vibration platform.

METHODS

The experimental protocol required 11 children and 10 adults to stand on a commercially available vibration platform at progressively greater frequencies (28, 33, and 42 Hz). Transmissibility of vibration to various skeletal landmarks was assessed with a high speed motion analysis system.

FINDINGS

Transmissibility in children was 42% and 62% greater than adults for the ankle and hip, respectively (P=0.03; effect size=0.84-1.29). The values at the head were not different between groups (P=0.92) and remained 86% and 50% lower than values at the ankle and knee, respectively (effect size=4.75-19.1).

INTERPRETATION

Transmissibility of whole body vibration while standing is not markedly different between children and adults. In fact, the only differences are the transmissibility to the ankle and hip which are greater in children when the vibration platform is set at 33 Hz. More importantly, transmissibility to the head is not different between groups. These results do not suggest vibration therapy is safe as the biological response of children to acute or chronic acceleration impacts during whole body vibration is unknown.

Pathology of retinal hemorrhage in abusive head trauma

Abusive head injury, characterized by repeated acceleration-deceleration forces, is associated with retinal hemorrhages as demonstrated in many clinical and postmortem studies. The theory that vitreoretinal traction is the major factor in the pathogenesis of retinal hemorrhages is presently the most widely accepted explanation based on different lines of research. Postmortem examination of the eye and orbital structures is essential for recognizing abusive head injury and also for identifying other possible medical conditions which can cause retinal hemorrhage.

Sensitivity of autopsy and radiological examination in detecting bone fractures in an animal model: Implications for the assessment of fatal child physical abuse

Skeletal injuries are often strong indicators of child abuse and their detection is therefore crucial. The aim of this study was to compare the sensitivity of three diagnostic approaches, namely autopsy, traditional (conventional) radiology, and computed tomography on "battered" piglets, in order to verify the sensitivity of each method, with respect to the true number of bone fractures assessed once the piglet was skeletonised (osteological control). Four newborn cadaver piglets who had died from natural causes were severely beaten post-mortem in every district of the body. Traditional radiography, computed tomography (CT) and autopsy were performed. The piglet was then macerated until skeletonised and the number of all fractures present recorded (osteological control). On the cranium, traditional radiology revealed only 35% circa of actual fractures, autopsy detected only 31% (P<0.01 for both comparisons versus osteological control), whereas CT imaging detected all fractures actually present. For ribs, radiology detected only 47% of all fractures present, and autopsy 65% circa (P>0.05 for both comparisons versus osteological control), while CT scans detected 34% (P<0.01). In suspected cases of fatal child abuse, we suggest that the bones of specific districts be directly analysed either at autopsy or by collecting specific diagnostic sites, such as parts of the rib cage, and subjecting them to maceration. The removed areas could be replaced with artificial material for cosmetic purposes. The authors stress the importance of combined radiological, CT scan, autopsy and osteological survey in the detection of perimortem bone fractures.

A computational study of the passive mechanisms of eye restraint during head impact trauma

A finite element model of the eye and the orbit was used to examine the hypothesis that the orbital fat provides an important mechanism of eye stability during head trauma. The model includes the globe, the orbital fat, the extra-ocular muscles, and the optic nerve. MRI images of an adult human orbit were used to generate an idealized geometry of the orbital space. The globe was approximated as a sphere 12 mm in radius. The optic nerve and the sclera were represented as thin shells, whereas the vitreous and the orbital fat were represented as nearly incompressible solids of low stiffness. The orbital bone was modelled as a rigid shell. Frontal head impact resulting from a fall onto a hard floor was simulated by prescribing to the orbital bone a triangular acceleration pulse of 200 g (1962 m/s(2)) peak for a duration of 4.5 ms. The results show that the fat provides the crucial passive mechanism of eye restraint. The mechanism is a consequence of the fact that the fat is incompressible and that its motion is restricted by the rigidity of the orbital walls. Thus, the acceleration loads of short duration cannot generate significant distortion of the fat. In contrast, the passive muscles provide little support to the globe. When the connection between the orbital fat and the eye is absent the eye is held mainly by the optic nerve. We discuss the possible role that this loss of contact may have in some cases of the evulsion of the eye and the optic nerve.

A case of shaken baby syndrome after discharge from the newborn intensive care unit

Preterm infants may be at higher risk of physical abuse after hospital discharge. Nonaccidental or inflicted head neurotrauma is the most common cause of mortality and morbidity in physical-abuse cases, and shaken baby syndrome (SBS) is the most common form of abuse. In the majority of the cases, parents who shake their infant do not intend to harm the infant. This article presents a report of a former preterm infant who presented to the pediatrician's office with a maternal report of an accidental fall. Shaken baby syndrome was suspected based on bilateral subdural hemorrhages of varying ages, which were inconsistent with the history provided. The differential diagnosis and systematic clinical evaluation for SBS are provided, and medical and nursing management is discussed. Patient care, advocacy, and mandatory reporting are reviewed. The newborn intensive care unit caregivers' role in preventing SBS in this high-risk population, including specific parent teaching and anticipatory guidance, is reviewed with an emphasis on teaching all caregivers about the dangers of shaking an infant.

Unnatural causes of sudden unexpected deaths initially thought to be sudden infant death syndrome

The aim of this clinicopathological study was to determine the frequency of infant deaths due to unnatural causes among cases of sudden and unexpected infant death. Nine institutes of legal medicine in Germany that took part in the German study on Sudden Infant Death Syndrome (GeSID), representing 35% of the German territory, investigated in a 3-year period (from 1998 to 2001) 339 cases of infant death that were not expected to be due to unnatural causes from the first external examination. All cases were investigated by complete, standardised, post-mortem examination including death scene investigation, autopsy, histology, toxicology and neuropathology. The frequency of unnatural deaths was 5.0% (n=17). The causes of death were head injury (n=7), suffocation (n=5), poisoning (n=2), neglect (n=2) and septicaemia due to aspiration of a foreign body (n=1). Two deaths were unsuspected accidents and 12 were due to infanticide. In 3 cases, it was not possible to differentiate between accidental death and infanticide. A complete postmortem examination including an analysis of the clinical history, death scene investigation, autopsy, histology, toxicology, and neuropathology is mandatory to differentiate sudden and unexpected deaths due to natural causes (e.g. SIDS) and cases of unnatural death.

Recent research and views on shaking baby syndrome

Primary care physicians and psychiatrists should be aware of the incidence, causes, diagnosis, and prognosis of the conditions of Shaking Baby Syndrome (SBS). This article discusses both accidental and non-accidental head injury, and also addresses the legal aspects of SBS. Incidence, potential causes, explanations, prevention, and treatment of the condition, both for the perpetrators and the unfortunate victims, are considered. Of special importance is the fact that SBS is difficult to diagnose with absolute certainty. Hence the identification of a potential perpetrator can be difficult and injustices can occur.

Retinal hemorrhages in an 8-year-old child: an uncommon presentation of abusive injury

OBJECTIVE

Retinal hemorrhages in pediatric patients have been best described as a component of shaken baby syndrome (SBS), which has been described almost exclusively in the infant/toddler population. We describe the occurrence of retinal hemorrhages in the setting of abusive injury in an older child.

METHODS

Case report.

RESULTS

An 8-year-old boy was transferred to our institution with coma and respiratory arrest. Evaluation demonstrated intracranial hemorrhage, cerebral edema, and severe bilateral retinal hemorrhages. The patient subsequently died of intractable intracranial hypertension. Police investigation confirmed that the injuries were caused by severe abusive injury, including shaking.

CONCLUSIONS

This case emphasizes that the diagnosis of SBS is not limited to babies and that the possibility of abusive shaking injury should also be considered in older children presenting with intracranial pathology and retinal hemorrhages.

Abusive head trauma in Maine infants: medical, child protective, and law enforcement analysis

OBJECTIVE

To collect and compare the results of medical, child protective, and law enforcement evaluation of a sample of Maine children who were victims of abusive head trauma (AHT) in order to describe the clinical and evaluative characteristics as they relate to victims, families and perpetrators of such trauma and to improve the professional response to AHT in Maine.

METHOD

Retrospective chart review of medical, child protective, and law enforcement records of all AHT victims admitted to two tertiary care hospitals in Maine or seen by the state medical examiner from 1991 to 1994.

RESULTS

Nineteen children (age range 2 weeks to 17 months) were identified as victims of AHT (out of a total of 94 head trauma admissions) accounting for 20 hospitalizations during the study period. There was a history of prior injury in 30%, history of prior medical evaluations for possibly abuse related problems in 65%, while, on presentation, 75% had evidence or history of prior injury. The hospitals notified child protective services (CPS) in all 20 cases and correctly identified abuse in 18 (90%). Parental risk factors for abuse identified in CPS records included substance abuse (53%), domestic violence (42%), criminal history (32%), unrealistic expectations (42%), and attachment problems (32%). However, risk factors were inadequately assessed in 53% of homes. Law enforcement identified a likely perpetrator in 79% of cases and in the majority the identified suspect was the father. In the 15 cases where a perpetrator was identified by law enforcement, that person was alone with the child at symptom onset in 14 (93%).

CONCLUSIONS

The medical response, at least at the inpatient level, was generally well done with regard to suspicion and reporting. Cases are possibly being missed at the outpatient level. Child protective risk assessment was limited overall yet in a third of the homes where AHT occurred, few if any risk factors were present to aid in identification and prevention. Law enforcement results suggest that a primary suspect for AHT is the caretaker alone with the child at the time of symptom onset.

Marked calvarial thickening and dural changes following chronic ventricular shunting for shaken baby syndrome

We report the case of a 23-year-old woman who was abused at the age of 5 months. She suffered from complications frequently associated with shaken baby syndrome, such as hydrocephalus secondary to subarachnoid hemorrhage. The patient underwent a procedure to place a ventriculoperitoneal shunt 3 weeks after her presentation with signs of abuse. The ventricular shunt remained in place throughout her life, and the patient received multiple revisions. She also was noted to have a markedly thickened calvarium on both radiographs and computed tomographic scan at 6 years old. She died following an episode of grand mal status epilepticus. An autopsy was performed and her skull was found to be thickened circumferentially. Histologic examination revealed increased cancellous space with normal trabecular bone. It is hypothesized that intracranial hypotension resulting from chronic ventricular shunting lead to her thickened calvarium, a condition previously reported as hyperostosis cranii ex vacuo. Dural changes seen microscopically corroborate this hypothesis.

Correlation between retinal abnormalities and intracranial abnormalities in the shaken baby syndrome

PURPOSE

To report correlation between retinal and intracranial abnormalities and to evaluate pathogenesis of retinal hemorrhages in the shaken baby syndrome (SBS).

DESIGN

Observational case series.

METHODS

Seventy-five children with apparent nonaccidental head trauma consistent with SBS had complete physical examination, complete ophthalmologic examination, neuroimaging by CT or MRI, or both, and skeletal radiographic survey. In this retrospective review, ophthalmoscopic and intracranial abnormalities were correlated.

RESULTS

The age of patients ranged from 2 to 48 months (mean - SD, 10.6 +/- 10.4 months). Neuroimaging was abnormal in all 75 cases. Findings included subdural hematoma (70 children, 93%), cerebral edema (33 children, 44%), subarachnoid hemorrhage (12 children, 16%), vascular infarction (nine children, 12%), intraparenchymal blood (six children, 8%), parenchymal contusion (six children, 8%), and epidural hemorrhage (one child, 1%). Sixty-four (64/75, 85%) children had retinal abnormalities, mostly (53/64, 82%) confluent multiple hemorrhages that were subretinal, intraretinal, and preretinal in 47/64 (74%) and bilateral in 52/64 (81%). No association was found between anatomic site (left, right, or bilateral) of intracranial and retinal findings (McNemar test kappa = -0.026-0.106) or between any of the intracranial findings mentioned above and the following retinal findings: normal or abnormal retinal examination, multiple (>10) or few retinal hemorrhages (< or =10), symmetric or asymmetric retinal findings, or retinoschisis (kappa = -0.127-0.104). Signs of possible increased intracranial pressure were not correlated with any retinal abnormality (kappa = -0.03-0.073). There was no correlation between evidence of impact trauma to the head and retinal hemorrhages (kappa = 0.058). Total Cranial Trauma Score and Total Retinal Hemorrhage Score, both indicating the severity of injury, were correlated (P =.032).

CONCLUSIONS

Our study supports previous observations that the severity of retinal and intracranial injury is correlated in SBS. We cannot support the suggestions that in most children with SBS retinal bleeding is caused by sustained elevated intracranial, elevated intrathoracic pressure, direct tracking of blood from the intracranial space, or direct impact trauma. The correlation in severity of both eye and head findings may suggest, however, that retinal abnormalities are the result of mechanical shaking forces.

Mild head injury increasing the brain's vulnerability to a second concussive impact

OBJECT

Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model to investigate the behavioral and pathological changes associated with RHI.

METHODS

Adult male C57BL/6 mice were subjected to a single injury (43 mice), repetitive injury (two injuries 24 hours apart; 49 mice), or no impact (36 mice). Cognitive function was assessed using the Morris water maze test, and neurological motor function was evaluated using a battery of neuroscore, rotarod, and rotating pole tests. The animals were also evaluated for cardiovascular changes, blood-brain barrier (BBB) breakdown, traumatic axonal injury, and neurodegenerative and histopathological changes between 1 day and 56 days after brain trauma. No cognitive dysfunction was detected in any group. The single-impact group showed mild impairment according to the neuroscore test at only 3 days postinjury, whereas RHI caused pronounced deficits at 3 days and 7 days following the second injury. Moreover, RHI led to functional impairment during the rotarod and rotating pole tests that was not observed in any animal after a single impact. Small areas of cortical BBB breakdown and axonal injury. observed after a single brain injury, were profoundly exacerbated after RHI. Immunohistochemical staining for microtubule-associated protein-2 revealed marked regional loss of immunoreactivity only in animals subjected to RHI. No deposits of beta-amyloid or tau were observed in any brain-injured animal.

CONCLUSIONS

On the basis of their results, the authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.

Seasonal variations in the incidence of suspected shaken baby syndrome

A retrospective review of cases at a level I pediatric trauma center from 1995 through 1999 was conducted to identify cases of suspected shaken baby syndrome. Cases were included if the primary diagnosis was associated with shaken baby syndrome, such as retinal hemorrhage or subdural hematoma. The daily temperature and month of admission were evaluated to identify possible seasonal variations in the incidence of suspected cases.

Manifestations of the shaken baby syndrome

Retinal hemorrhages are the most common fundus finding in the shaken baby syndrome. They vary in type and location; no particular type is pathognomonic for the condition. Retinal hemorrhages are not needed to make a diagnosis of shaken baby syndrome. However, in a child under age 3 years, the presence of extensive bilateral retinal hemorrhages raises a very strong possibility of abuse, which must be investigated. The other possible causes for hemorrhages in this age child can be investigated and eliminated. The diagnosis of abuse should be made by someone particularly trained in this area, who can put together the entire picture of inadequate or changing history, fractures of various ages, particularly rib fractures, subdural hematoma of the brain, and retinal hemorrhages. Photographs of retinal hemorrhages are very helpful to child advocacy experts who take these cases to court.

Neurology and the skin

As knowledge of pathophysiology grows, so does the refinement of diagnoses. Sometimes increased knowledge permits consolidation and unification. Unfortunately, at our present level of understanding, it usually demands proliferation of diagnostic categories. As tedious as this diagnostic splintering may seem, such is the price currently exacted of both the investigator and the clinician who seek to optimise management. Increased diagnostic refinement often requires inquiry into matters outside the bounds of one's specialty. Most often we turn to the radiologist or to the laboratory to narrow the differential diagnosis generated from the history and neurological examination. As we have shown, a useful intermediate step is extension of the physical examination to organs such as the skin, which are not the traditional preserve of the neurologist. That any text could confer the sophistication required for expert dermatological diagnosis is an unrealistic expectation. However, we hope that this review will encourage careful examination of the skin, hair, and nails by the neurological practitioner, with consideration of referral to a dermatologist when greater expertise is required.