Neonatal Injuries in Child Abuse

Background

Child abuse is often misdiagnosed and under recognized by physicians and caregivers. Child abuse occurs in many forms and is best defined as purposeful infliction of physical or emotional harm, sexual exploitation, and/or neglect of basic needs (eg, nutrition, education, medical care). Child abuse is an important cause of death in children. Among child abuse fatalities, head injury is the leading cause of death in infancy.

Shaken baby syndrome (SBS) is of particular interest to the neurologist, as it affects the nervous system. Shaken baby syndrome may cause long-term sequelae in the developing nervous system, and the effects may even be lethal. See the image below.

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T2-weighted MRIs show encephalomalacia after shaken baby syndrome.

In 1946, Caffey reported a series of patients with multiple fractures and chronic subdural hematoma, which fit the profile of what is now defined as shaken baby syndrome.^[1] Kempe et al coined the term battered child syndrome.^[2] In 1967, Gilkes and Mann first reported the funduscopic findings of battered babies.^[3] In 1972, Caffey wrote about the syndrome of shaken infants. His report brought attention to this form of child abuse.^[4]

The term "shaken baby syndrome" has been commonly used to describe symptoms consistent with shaking an infant, which produces bilateral retinal hemorrahge and diffuse brain injury. However, the term shaken impact syndrome is used for injuries that exceed those just from shaking and have evidence of blunt head trauma. The American Academy of Pediatrics in 2009 recommended the use of the term "abusive head trauma," rather than shaken baby syndrome or non-accidental injury.^[5] This term describes the type of injury rather than the mechanism of injury.

Abusive head trauma (AHT) is a well-recognized brain injury associated with the direct application of force to an infant that results in physical injury to the brain and/or its contents.^[6]

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Pathophysiology

Anatomic features make infants especially prone to neurologic injury from excessive shaking or trauma. Infants have a large head compared with their body size, and the cervical paraspinal muscles are weak. (This accounts for head lag observed during the first month of life.) The infant brain has a higher water content than that of the adult brain, and it is incompletely myelinated. The subarachnoid spaces are also larger in infants than in adults, given the small size of their brains.

When the infant is shaken, movement of the immature brain in relation to the skull and the poor muscle tone in the neck cause the bridging vessels to tear, resulting in the classic finding of a subdural hematoma. Retinal hemorrhages are produced when venous congestion causes rupture of the retinal vasculature. Therefore, shaken baby syndrome is defined by subdural hemorrhage and retinal hemorrhage. One additional feature is occult fractures, particularly of ribs and long bone metaphyses.

The mechanism by which brain damage occurs is controversial. Traditionally, shearing forces from direct trauma were believed to cause axonal damage. Geddes et al suggested hypoxia-ischemia as the mechanism rather than axonal injury that is seen in older children and adults with lethal head trauma.^{[7, 8]} They also thought that acceleration and deceleration forces may damage the neuraxis to cause apnea, with consequent ischemia and cerebral edema.

Biomechanical studies of infant trauma injuries have shown that the magnitude of angular deceleration is 50 times greater when the infant's head strikes a surface than when he or she is only shaken. This force is distinct from those of other accidental traumas that occur in infants. This evidence suggests that the term shaking-impact syndrome is more accurate than shaken baby syndrome.

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Epidemiology

Frequency

In 2021, an estimated 1820 children died from abuse and neglect in the United States. In the same year, 51 states reported 588,229 victims of child abuse and neglect; 76.0% of victims are neglected, 16.0% are physically abused, 10.1% are sexually abused, and 0.2% are sex trafficked. The youngest children were most vulnerable to maltreatment. Children younger than 1 year old have the highest rate of victimization at 25.3 per 1000 children of the same age in the national population. The victimization rate for girls is 8.7 per 1000 girls in the population, which is higher than boys at 7.5 per 1000 boys in the population.^{[9, 10]}

Mortality/morbidity

Abuse and neglect account for 5–14% of all deaths of children. The youngest children were most vulnerable to maltreatment. Children in the first year of their life had the highest rate of victimization 25.3 per 1000 children nationwide.^{[9, 10]}

In Missouri, 30 out of 35 children who died from inflicted abuse or neglect at the hands of a parent or caregiver were four years of age or younger. Of those, 13 were infants younger than one year.^[11] In Illinois in 2016, incidence of child abuse–related deaths was 216 per 100,000 children.{ref42-INVALID REFERENCE}

Sex

Boys are affected more often than girls.

The perpetrator is usually alone with the victim. Men are the abusers in 90% of cases. The abuser is usually the biologic father or, in some cases, the mother's boyfriend. The most common female attacker is a babysitter.

According to a Philadelphia-based study, 1 in 7 mothers who were abused as children admitted to using corporal punishment on their children.^[12]

Age

More than 600,000 children are abused in the United States each year. Children in the first year of their life account for 15% of all victims, and 28% of child maltreatment victims are no more than 2 years old. The typical abused child is younger than 6 months.^[10]

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Prognosis

The prognosis depends on the severity of the neurologic injury and the involvement of other organ systems.

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History

More than half of the patients who present to the emergency department (ED) or a physician's office with suspected child abuse have no history of previous abuse. One fourth have a history of minor trauma. A small percentage present with a seizure, with varying levels of consciousness (eg, coma, apnea, respiratory arrest). Other symptoms include failure to thrive, poor feeding, and other vague symptoms.

The typical patient is a frequent visitor to the ED because of various symptoms. Common historical accounts that suggest abuse include injury inflicted by sibling, a fall down the steps, suddenly turning blue and stopping breathing, being left alone for a few minutes, and falling from a low height.

Patients occasionally present with minor symptoms, such as earache, ear pulling, cough, or colds.

The true nature of the problem is often discovered only after CT is preformed and evidence of intracranial pathology is found.

The most common intracranial lesion is subdural hemorrhage. The symptoms are related to signs of increased intracranial pressure, but some patients have no evidence of increased intracranial pressure. Other findings are cerebral edema, subarachnoid hemorrhage, and even intraparenchymal hemorrhage. Interhemispheric bleeding is an early and specific finding in intracranial bleeds caused by shaking.

Skull fractures are seen in as many as 95% of patients with serious intracranial injury. The fracture is usually in the occipital or parietal bones.

Abuse should be considered if the patient has bilateral depressed fractures or multiple fractures, especially if they cross the suture lines.

Retinal hemorrhage is a characteristic and diagnostic feature of shaken baby syndrome. It can be detected even before intracranial hemorrhages are seen. Several types of retinal hemorrhages have been described.

Whether cardiopulmonary resuscitation (CPR) can cause retinal hemorrhage is controversial. Kanter evaluated 54 patients for retinal hemorrhage after CPR. Among the patients, 45 had no trauma, and only 1 patient (2%) had evidence of retinal hemorrhage. Of the 9 patients who had evidence of trauma, 5 had retinal hemorrhage, and 4 of had evidence of child abuse.^[13] CPR-associated retinal hemorrhages rarely, if ever, occur. However, if they do occur from CPR, they are few in number and confined to the posterior pole.^[14]

Characteristics of retinal hemorrhages in abusive head trauma are bilateral, although asymmetric and unilateral are well recognized. In most cases of abusive head trauma, they are too numerous to count and extend to the ora serrata. Two thirds of retinal hemorrhages associated with abusive head trauma occur in multiple layers.^[14]

In 1998, Jayawant identified 9 characteristics of supposed and proven nonaccidental injury in children with subdural hematoma. These characteristics suggest a set of criteria that may be used to increase the precision of diagnosis.

• Boys account for two thirds of the children studied.
• Four fifths of the perpetrators are men.
• In about one eighth of all cases, the child and/or his or her siblings were previously abused by the same perpetrator.
• More than half of the caregivers change their stories several times.
• About half of all perpetrators eventually admit to shaking the child.
• About half of all patients have a hemoglobin level of less than 10 g/L at presentation.
• The skeletal survey is positive in 60% of cases involving nonaccidental injury.
• About 60% of patients have evidence of present or past trauma.
• Retinal hemorrhages are present in 80% of patients.

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Physical

Ludwig and Warman in 1984 characterized the presenting physical findings of shaken baby syndrome.^[14]

• An enlarged head circumference was seen in slightly more than half of all patients, as was a bulging fontanelle.
• Nonspecific bruising was noted in one third of the patients.
• Neurologic involvement was seen in fewer than 50% of patients.

The key to diagnosis is the presence of retinal hemorrhages, which are seen in 80% of patients.

Retinal hemorrhage is considered the hallmark of shaken baby syndrome. Retinal hemorrhages can be seen as early as 48 hours before any intracranial lesions can be detected on brain CT or MRI.

After vaginal delivery, retinal hemorrhages are occasionally seen without intracranial lesions. The incidence of perinatal retinal hemorrhages ranges from 20-30% among infants examined in the first 24 hours of life and 10-15 % in infants examined the first 72 hours of life. These hemorrhages appear to be related to obstetrical and perinatal changes, as well as peripartum prostaglandin release. They can occur with any type of delivery but are more common in deliveries that are spontaneous vaginal deliveries or with vacuum assisted. Perinatal retinal hemorrhages may be numerous and extend to the periphery.^[15]

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Causes

Certain risk factors increase the probability of child abuse.

• Characteristics of the child abuser include increased stress, social difficulties, and low educational achievement. Cases of abusive head trauma have doubled during the recent recession.^[16]
• Crying of the infant or child may also play a role.
• Infants who are premature and have congenital defects, developmental delays, or difficult temperament are at greater risk for child abuse, possibly due to poor parental bonding.

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Complications

The main complications after shaken baby syndrome affect the neurologic and visual systems.

After retinal hemorrhages resolve, the following visual complications may occur: macular thinning, retinal pigment epithelial atrophy, and visual loss.

Wilkinson et al showed that the degree of retinal hemorrhage reflects the degree of neurologic injury.^[17]

Patients with bilateral retinal hemorrhages tend to have acute, severe neurologic injury.

Large subhyaloid hemorrhage, vitreous hemorrhage, or diffuse involvement of the fundus is likely to be associated with severe neurologic injury.

Neurologic complications include varying degrees of learning disabilities, spasticity and weakness, hydrocephalus, developmental delay, acquired microcephalus, seizures, hearing loss, and cortical blindness.

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Laboratory Studies

Laboratory studies for shaken baby syndrome/abusive head trauma are nonspecific and are not diagnostic.

• Leukocytosis is seen in approximately 50% of patients.
• Serum chemistry findings are usually normal, but they may reveal evidence of acidosis.
• The cerebrospinal fluid may be bloody, possibly indicating subarachnoid hemorrhage.
• Obtain urine for organic acids to rule out a diagnosis of glutaric acidemia.

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Imaging Studies

According to the 2020 policy statement on abusive head trauma (AHT) in infants and children from the American Academy of Pediatrics, a skeletal survey for any child < 2 years with suspicious injuries can identify occult injuries that may exist in abused children and is very useful in the evaluation of suspected abuse.^[18]

The key to diagnosing shaken baby syndrome/abusive head trauma (SBS/AHT) is neuroimaging. The true nature of the problem is often discovered only after CT is performed and evidence of intracranial pathology is found. CT scanning of the brain is sufficient to diagnose subdural hemorrhage (see the first image below), cerebral edema (see the second image below), and/or subarachnoid hemorrhage. CT is usually the first neuroimaging study obtained in the ED.

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CT scan shows a subdural hematoma.

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CT scan shows cerebral edema with loss of gray matter–white matter distinction.

As a follow-up study, MRI can be used to determine the extent of the neurologic injury (see the images below). MRI may be helpful for continued management and prognosis.

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T1-weighted MRIs reveal bilateral chronic subdural hematomas as well as severe encephalomalacia involving the parietal, occipital, and temporal lobes.....

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T1-weighted MRIs show chronic bilateral subdural hematomas.

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T2-weighted MRIs show encephalomalacia after shaken baby syndrome.

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Sagittal MRIs show chronic subdural hematoma.

Retinal hemorrhages can be seen as early as 48 hours before any intracranial lesions can be detected on brain CT or MRI. As long as the fontanelle is still open, ultrasonography can be performed to identify an intracranial hemorrhage. However, a negative head sonogram does not rule out intracranial pathology.

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Other Tests

An ophthalmologic evaluation is extremely important and helpful in diagnosis.

A dilated eye examination is preferred. However, in the ED, all patients (regardless of the presenting complaint) should receive retinal examination with a direct ophthalmoscope.

Papilledema indicates increased intracranial pressure, and retinal hemorrhage strongly suggests shaken baby syndrome (see the image below).

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Funduscopic image shows intraretinal hemorrhages, subhyaloid hemorrhages, localized hemorrhagic choroid detachments, and thin retinal folds.

All patients in whom abuse is suspected must be given a long-bone skeletal survey to check for new or healing fractures, which help in the diagnosis.

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Approach Considerations

The child abuse patient may require continued physical and occupational therapy after discharge. Continued follow-up with a neurologist is recommended. Closely watch the patient for spasticity, and control this with medication as needed.

Further inpatient rehabilitation therapy may be indicated to manage the acute intracranial pathology, depending on the severity of injury. If long-term inpatient care is required, the patient should be transferred to a pediatric rehabilitation unit for maximal multidisciplinary care.

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Medical Care

Supportive care is the mainstay of treatment in child abuse.

• Blood pressure and vital signs should be supported and maintained.
• Provide mechanical ventilation as needed.
• Treat increased intracranial pressure, if present.

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Surgical Care

Intracranial monitoring may be necessary, especially when intracranial pressure is a problem.

In the presence of subdural hematoma, surgical evacuation may be necessary.

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Consultations

Consult an ophthalmologist who is well versed in identifying eye findings in abused children. The ophthalmologist is required for the initial ophthalmic evaluation and possibly for follow-up as well.

Appropriate referral to the state or county protective (abuse) center is necessary to identify siblings who may be at risk of abuse.

Referral to a physician who specializes in abuse can be helpful but not mandatory.

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Activity

Physical therapy and occupational therapy can be helpful after neurologic injury.

Speech therapy might be beneficial for patients in whom speech and/or language may be affected.

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Medication Summary

Antiepileptic medication may be indicated if evidence of seizures is noted.

Neurosurgeons tend to prescribe prophylactic therapy for all patients. However, this practice is not a universal recommendation.

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