Recent Studies in Child Abuse and Neglect: Neonatal Injuries in Child Abuse (2009)

Perpetrator information is highlighted in bold.

http://emedicine.medscape.com/article/1176849-overview

Neonatal Injuries in Child Abuse
Author: Nitin C Patel, MD, MPH, Associate Professor of Clinical Neurology and Child Health, Department of Child Health, Interim Division Chief for Developmental Pediatrics and Child Neurology, Specialist in Pediatrics/Neurology, University of Missouri Hospital and Clinics at Columbia
Coauthor(s): Robin D Davenport, BS, MSN, Pediatric Nurse Practitioner, Department of Pediatric Neurology, University of Missouri Health Care Hospitals and Clinics; Bhagwan I Moorjani, MD, FAAP, FAAN, Consulting Staff, Department of Neuroscience, Director, Department of Neuroscience, Division of Evoked Response Laboratory, Children's National Medical Center
Contributor Information and Disclosures

Updated: Mar 18, 2009

Child abuse is often misdiagnosed and underrecognized 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).

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.

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

For related information, see eMedicine's article Child Abuse & Neglect, Physical Abuse.

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.

The mechanism by which brain damage occurs is controversial. Traditionally, shearing forces 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.5,6 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.


Frequency
United States
Approximately 47.8 of every 1000 American children are mistreated. In 2006, 3.6 million cases of child abuse and neglect were reported. Of these, 905,000 cases were substantiated. In the first year of life, accidental injury occurs more often than intentional injury. The incidence of trauma in children younger than 12 months is approximately 24.4 cases per 1000 children per year.7

International
Good statistical data are not available.

Mortality/Morbidity
Abuse and neglect account for 5-14% of all deaths of children. In 2006 in the United States, 1530 fatalities from child abuse were reported, and 45% involved infants younger than 12 months. In Missouri, the number of substantiated fatalities in 2006 decreased from the previous year; 27 children died as a result of child abuse or neglect in 2006, compared to 32 deaths in 2005.8 Shaken baby syndrome is reported to be the leading cause of death in children younger than 4 years.

In children younger than 1 year, homicide is the leading cause of death. This is the only cause of death in children that is increasing in frequency.
In a series of 80 patients younger than 2 years who had head trauma and died because of the injury, 43% had evidence of child abuse.

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.9

Age
In 2006, 3.6 million cases of child abuse and neglect were reported. Of these, 905,000 cases were substantiated. About 14.2% of the affected children were younger than 3 years, and 24.4% were younger than 1 year.7
The typical abused child is younger than 6 months.

Clinical History
More than half of the patients who present to the emergency department (ED) or a physician's office with suspected above 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 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.
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.10
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.
Physical
Ludwig and Warman in 1984 characterized the presenting physical findings of shaken baby syndrome.11
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.
Causes
Certain risk factors increase the probability of child abuse.

Characteristics of the child abuser include increased stress, social difficulties, and low educational achievement.
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.