Neonatal Injuries in Child Abuse Cases
Anatomic Features That Make Infants Prone to Neurologic Injury From
Sep 22, 2009
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. Child abuse has a number of synonyms such as "non-accidental injury" (NAI) and the "battered child syndrome"(Understanding Child Maltreatment, CDC Fact Sheet 2006).
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. Shaken baby syndrome is reported to be the leading cause of death in children younger than 4 years.
Retinal hemorrhage is a characteristic and diagnostic feature of shaken baby syndrome. It can be detected even before intracranial hemorrhages are seen. Retinal hemorrhages are present in 80% of patients. Other findings are cerebral edema, subarachnoid hemorrhage, and even intraparenchymal hemorrhage. The most common intracranial lesion is subdural hemorrhage.
Anatomic Features in Infants
“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,” says the Journal of Pediatric Health Care in a 2005 article entitled “Physical abuse: Recognition and reporting.” 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. 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 (Journal of Pediatric Health Care).
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 (Journal of Pediatric Health Care).
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.
Mortality Rates
Abuse and neglect account for 5-14% of all deaths of children. In children younger than 1 year, homicide is the leading cause of death and is the only cause of death in children that is increasing in frequency. 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 (Journal of Pediatric Health Care).
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.The typical abused child is younger than 6 months.
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