Pediatric abusive head trauma (AHT) most often involves brain injury of infants and young children. Another term for this condition is shaken baby syndrome (SBS). Shaking, blunt impact, or the combination can result in neurological injury.
Abusive head trauma typically involves injury to the intracranial contents or skull of an infant or child younger than 5 years old as a result of violent shaking or blunt impact. The outcome ranges from complete recovery to significant brain damage and death.
Brain and head injuries are the most common cause of traumatic death in children less than 2 years. Early diagnosis is essential but may prove challenging. Often the individuals responsible are evasive. Health professionals may not recognize the signs and symptoms due to frequent lack of external signs of head trauma or abuse.
The solution to avoiding abusive head trauma is caregiver education to avoid accidental pediatric abusive head trauma and shaken baby syndrome, and to train health providers to recognize the signs and symptoms. Preventive mental health care is the best option to reduce child abuse. For those children that survive, the long-term financial, medical burden is extensive.
Caregivers rarely admit to the deliberate abuse of infants and children. They are usually evasive, fear repercussions, and invent “accidents” such as:
Definitions and Considerations
Unless head injuries are obvious, clinicians and healthcare providers may overlook the signs and symptoms of abusive head injury. There are patterns of injuries that suggest abusive head trauma or child abuse. Healthcare providers need to be aware of the typical injuries associated with accidents versus those associated with abuse.
Abusive Head Trauma (AHT)
Pediatric Acquired/Traumatic Brain Injury (PA/TBI)
Shaken Baby Syndrome (SBS)
Other terminologies involving shaken baby syndrome include:
Risk factors for abusive head trauma may include behaviors and situations that involve the child, the family, and the caregiver. Infants who inconsolably cry are at risk of a frustrated caregiver responding with violent shaking. Colic is a risk factor. Infant crying is greatest at 6 to 8 weeks of age and then declines. As a consequence, abusive head trauma peaks during this same period.
Risk factors for abusive head trauma include:
Acute head trauma perpetrators are most often the father or stepfather, mother’s boyfriend, female babysitter, and the mother. Shaking is often associated with the perpetrator’s level of frustration and tension.
Child abuse affects all ethnicities, socioeconomic groups, and races with boys and adolescents more commonly affected. Infants tend to have increased morbidity and mortality with physical abuse. Multiple factors increase a child’s risk for abuse. These include risks at an individual level such as disability of the child, unmarried mother, maternal smoking, and parent’s depression. Risks at a familial level are domestic violence at home and more than two siblings at home. Risks at a community level are isolation, lack of recreational facilities, and societal factors such as poverty. Other factors include living in an unrelated adult’s home and being a child previously reported to child protective services (CPS). All of these increase the chance of child maltreatment. There are also protective factors that decrease the risk of child maltreatment, which include family support and parental concern. Preventive factors include parental education regarding child development and parenting, social support, as well as parental resilience.
The shaken baby syndrome is difficult to diagnose. As a result, the incidence is uncertain. This is a result of lack of a centralized reporting system, signs of maltreatment not being present, unclear presentation, and acute head trauma not being a single isolated event but one that is part of chronic neglect and abuse that ends in severe morbidity and mortality.
In the first year of life, the incidence of abusive head trauma is estimated to be approximately 35 cases per 100,000 infants. The morbidity and mortality from abusive head trauma are significant. Approximately 65% have significant neurological disabilities, and 5% to 35% of infants die of injuries sustained. Most survivors have cognitive and neurologic impairment.
Abusive head trauma is a subset of a much larger problem. Each year, millions of families of children are investigated by the Child Protective Services for abuse and neglect. On average, over 3 million children per year are the subject of maltreatment reports. Of those, 20% are found to have confirmatory evidence of maltreatment.
Unfortunately, despite extensive research, there are no accurate statistics. Experts believe the incidence of pediatric abusive head trauma is about 1000 to 1500 infants per year. According to the Centers for Disease Control and Prevention (CDC), of the 2000 children who die from abuse annually, abusive head trauma accounts for approximately 10%. The victim of the shaken baby syndrome is typically between 3 and eight months. It is also reported in newborns and children up to 4 years of age. Up to 25% of all children diagnosed with shaken baby syndrome die from their injuries.
Abusive pediatric head trauma most often begins with anger and frustration over a screaming infant that will not stop crying. Triggers include:
An incident of abusive head trauma forever changes caregivers lives and families. Abusive head trauma is one of the most dangerous forms of child abuse. It is the number one cause of death in children younger than 2 years old. The majority of fatal injuries related to child abuse occur as a direct result of abusive head trauma.
The mechanism of abusive head trauma is shaking injuries that occur from repetitive rapid flexion, extension, and rotation of the head and neck. The rapid movement of the brain striking the skull can tear vessels resulting in bleeding around the brain and a hematoma. An enlarging hematoma may cause pressure within the skull, resulting in more brain damage.
Sheering forces across the brain injure nerve axons resulting in diffuse axonal injury. Infant’s heads are large and heavy, and the neck muscles are still too weak to support a large head. Rapid and repetitive flexion, extension, and rotation result in greater movement. When the impact of the head occurs against an object, additional injuries such as lacerations, bruises, and fractures are seen. Even impact against soft objects can result in significant injury.
Abusive head trauma typically causes:
Infants and young child are more susceptible to head injuries than older children for many reasons:
Abusive head trauma is a difficult diagnosis to make, and it is often misdiagnosed because of a misleading history, a variety of presentations, and a lack of consistent physical signs of injury. After shaking, infants and children may have findings ranging from nonspecific symptoms that do not require urgent care to acute life-threatening complications. Health care providers will initially misdiagnose a third of infants and children with abusive head trauma. Typically it takes as many as 3 visits to a health care provider for a correct diagnosis. By then the initial insult may be compounded by recurrent episodes of shaking. Furthermore, delay in diagnosis often results in increased complications and reinjury.
The initial signs and symptoms of abusive head trauma include decreased interaction, lack of a social smile, poor feeding, vomiting, lethargy, hypothermia, increased sleeping, and failure to thrive. Often these signs and symptoms are mistaken for a virus or other minor illness.
Signs and Symptoms of Abusive Head Trauma
The most severe cases of trauma will present with life-threatening signs and symptoms. The individual or individuals responsible may not bring the infant or child in for treatment out of fear of legal repercussions and in hopes that the infant or child will recover over time. Unfortunately, delayed care often has devastating effects on the short and long-term prognosis.
The infant or child may present with mild flu-like signs and symptoms or extreme illness which includes apnea, severe respiratory distress, bradycardia, bulging fontanel, decreased consciousness, seizures, and cardiovascular collapse.
A lack of external injury should suggest the possibility of abusive head trauma. A careful physical exam in some cases can uncover signs of abusive injury. Exam findings include:
Since many infants and children with abusive head trauma are initially asymptomatic or present with mild symptoms, universal neurologic screening for occult intracranial injury should be considered on all patients. Physical manifestations of abusive head trauma include cerebral atrophy, subdural and subarachnoid hemorrhages, retinal hemorrhages, hydrocephalus, and unexplained fractures. The primary neurological indicator of abusive head trauma is altered consciousness, developmental delays, seizures, nausea, and vomiting.
Retinal hemorrhages are usually more severe in abusive head trauma than accidental blunt head injury. Retinal hemorrhage is also significantly more common in abusive head trauma than in infants injured accidentally. Retinal hemorrhage in abusive head trauma involves most of the retina, from the ora serrata to the posterior pole of the eye.
Obtaining an ophthalmology consultation within the first 24 hours is important. Small-dot or superficial hemorrhages often resolve quickly. Less dramatic retinal hemorrhages are also found in children as a result of many other causes, such as accidental head trauma, anemia, birth trauma, coagulopathy, cerebral aneurysm, leukemia, and meningitis. As a result, healthcare providers should not use retinal hemorrhage alone to diagnose abusive head trauma. Further, the absence of retinal hemorrhage confined to the posterior pole also does not rule out abuse.
A subdural hematoma is a common finding in abusive head trauma. Acceleration-deceleration force causes the brain to move within the fixed venous channels and skull. Hemorrhages occur in the subarachnoid and subdural space if there is tearing of the superficial cortical veins.
Rib fractures in an infant are common with child abuse. They occur with squeezing the infant’s chest, which generates anterior-posterior compressive forces resulting in fractured ribs. Accidental rib fractures are very uncommon. Most caregivers will deny a history of trauma. The fractures are detected on routine chest x-ray or a skeletal survey. Rib fractures from CPR are also very rare. Essentially, any infant or child with a rib fracture and a history that does not strongly support legitimate trauma should induce further clinical investigation which should include a chest x-ray and a skeletal survey.
Skull fractures are a result of a direct force applied to the head. They may be due to accidental or inflicted head trauma. Abusive head trauma should be considered when the fracture is complex, diastatic (width greater than 3 mm), multiple, occipital, and non-parietal. Any of these types of skull fractures should suggest the possibility of abusive head trauma.
Long bone, posterior rib, or metaphyseal “corner” fractures, are seen more often in abusive head trauma than in accidental head injuries.
Metaphyseal fractures involve the distal and proximal tibia, proximal humerus, and distal femur. They are known as “bucket-handle” fractures because from certain angles they appear to have a curvilinear structure coming from the metaphysic. They are seen in infants and children and are highly specific for child abuse. The mechanism is shearing and torsional strains of the metaphysic near the physis. This is caused by shaking, twisting, or pulling on the extremities.
Abusive head trauma does not always present with retinal or subdural hemorrhage, or traumatic brain injury. Unexplained cervical spine injuries, seizures, or fractures should also lead the clinician to consider abusive head trauma.
If abusive head trauma is a consideration, a detailed diagnostic evaluation is necessary. Evaluation should include a comprehensive history, physical, laboratory testing, imaging, and consultation with specialists. 
The evaluation should include a review of the timeline of the signs and symptoms leading up to the evaluation. Clinicians should ask open-ended questions that can minimize unintentional bias and allow the opportunity to learn alternative explanations for injuries. A history that does not include trauma or a fall from a low height is the most common history in cases of abusive head trauma. Caregivers of children injured accidentally will usually report a history of trauma. An inconsistent history, or history that changes are suggestive of abusive head trauma and child abuse. The clinician should identify the development and progression of symptoms. Signs and symptoms of abusive head injury occur immediately in over 90% of infants who suffer shaking.
The physical exam should include a head to toe assessment. Particular attention should be placed on the neurologic exam.
Imaging studies are the most likely test to confirm abusive head trauma. The clinician should initially obtain a skeletal survey and head CT scan.
The head CT is the most helpful test in the diagnosis of intracranial injury from abusive head trauma. While definitive if positive, a CT may not detect edema, fractures, or shear injury.
An MRI can help distinguish a chronic subdural from subarachnoid collections, detect subacute and chronic subdural blood, and define the extent of a parenchymal injury. The use of diffusion MRI may further assist in obtaining an accurate diagnosis.
A skeletal survey should be obtained in any child younger than two years of age with unexplained traumatic injuries.
A skeletal series consists of plain radiographs of the spine, skull, ribs and long bones. They are commonly successful in identifying abuse. A “babygram,” which is a single image, should be avoided because of the poor detail it provides. Follow-up rib films should be considered 2 or 3 weeks after the initial skeletal survey to evaluate for healing fractures that were not seen in the acute phase.
Bone scans are an alternative to skeletal surveys and are used if there is a high suspicion of fractures that did not show up on a skeletal survey. Bone scans are more expensive and difficult to perform. Also, bone scans expose the child to more radiation.
Laboratory studies should include complete blood cell count with platelet count, chemistry panel, prothrombin time, partial thromboplastin time, amylase, lipase, aspartate aminotransferase, alanine aminotransferase, and urinalysis. The laboratory evaluation may suggest abusive head trauma by uncovering additional injuries that support child abuse or by finding an underlying disease that would be misdiagnosed as child abuse or abusive head trauma.
Most of the care of abusive head trauma is supportive. Vital signs should be monitored. Intubation and mechanical ventilation may be required. Intracranial pressure, if present, should be monitored and treated. If there is a subdural hematoma, surgical evacuation should be considered. The goal of therapy is to maintain a low intracranial pressure while maintaining acceptable blood pressure, ensuring adequate cerebral perfusion pressure (CPP).
The initial management of a child with a traumatic brain injury is maintaining the patient’s airway, breathing, and circulation. Children with no alterations of consciousness and normal blood pressure may be managed with supportive care. Hypotension is treated with fluid boluses. Those with a with Glasgow coma score of less than 9, marked respiratory distress, or hemodynamic instability may require advanced airway management to enhance oxygenation and ventilation and prevent aspiration.
Cervical spine immobilization must be maintained during advanced airway procedures. Consider the immediate brain injury resulting from the initial traumatic forces equally important to the two forms of secondary brain injury that may occur. The first form of secondary brain injury includes coagulopathy, hypoxemia, hypotension, intracranial hypertension, hypercarbia, hyperglycemia or hypoglycemia, electrolyte abnormalities, enlarging hematomas, seizures, and hyperthermia. The acute management of severe head-injury is to ameliorate those circumstances that lead to secondary brain injury. Secondary brain injury is a consequence of an endogenous cascade of cellular and biochemical events that occur within minutes in the brain and continues for months after the primary brain injury that lead to ongoing traumatic axonal injury (TAI) and neuronal cell damage and ultimately, neuronal cell death. The following conditions can exacerbate secondary brain injury:
Oxygenation is monitored using pulse oximetry, with supplemental oxygen administered to ensure adequate oxygenation. For initial monitoring of ventilation of traumatic brain injury, capnography is recommended to monitor end-tidal carbon dioxide to avoid excessive hyperventilation and hypocapnia, thereby leading to vasoconstriction and decreased cerebral perfusion. Intracranial pressure management is crucial to prevent secondary brain injury. Raising the head of patients to 30 degrees optimizes cerebral perfusion pressure and decreases intracranial pressure by improving venous drainage without affecting cerebral blood flow.
Traumatic brain injury can cause intracranial hypertension. These patients require sedation with barbiturates which lowers intracranial pressure by decreasing cerebral metabolism which decreases cerebral blood flow.
Therapeutic hypothermia reduces cerebral metabolic demands, cell death, excitotoxicity, inflammation, acute seizures, and lipid peroxidation. Hypothermia less than 35 C is used with neuromuscular blockade to prevent shivering.
If the diagnosis of abusive head trauma is being considered, other causes should be excluded. Accidental head trauma, birth trauma, bleeding diathesis, congenital conditions, neoplastic conditions, metabolic conditions, meningitis, connective tissue diseases, and obstructive hydrocephalus are all in the differential. These conditions have similar findings as abusive head trauma and must be excluded. Other considerations include osteogenesis imperfecta, glutaric aciduria, vitamin K deficiency, and rebleeding into a prior subdural hematoma.
The differential diagnosis includes:
Injuries That May Be Abusive Head Trauma
Researchers have attempted to classify the stage or severity of the injuries as mild (15%), moderate (13%), and severe (70%). The results of the classification reveal some disturbing findings.
Four variables predict abusive head trauma with 98% accuracy.
There are substantial morbidity and mortality associated with abusive head trauma. Morbidity ranges from mild learning disabilities to severe cognitive or physical abnormalities and death. Blindness, attention deficit, developmental delays, intellectual deficits, sensory deficits, hearing impairment, motor dysfunction, failure to thrive, feeding difficulties, seizures, behavior, and educational difficulties are expected manifestations. 
Abusive head trauma may also cause hemiplegia, quadriplegia, hydrocephaly, and microcephaly. The prognosis of patients with abusive head trauma correlates with the extent of injury identified on CT and MRI imaging.
Long-term, survivors of abusive head trauma that was severe have a substantial reduction in quality of life. Even those with mild injuries may have a substantial lifetime impairment.
Studies have evaluated the neurodevelopmental outcomes after abusive head trauma versus accidental head injuries. They found that infants younger than 36 months old with abusive head trauma experience more frequent non-contact injury mechanisms that result in cardiorespiratory compromise, deeper brain injuries, diffuse cerebral hypoxia-ischemia, and worse outcomes than those with an accidental head injury. Children diagnosed with abusive head trauma are more likely to die than children with accidental head trauma.
Abusive head trauma commonly causes a number of long-term sequelae. More than 50% of children will have partial or complete blindness. Another 5% need eye surgery, and more than 20% will require a feeding tube after the injuries.
Patients with retinal hemorrhages which are bilateral tend to have acute, severe neurologic injury. Large subhyaloid hemorrhage, diffuse involvement of the fundus, or vitreous hemorrhage are associated with neurologic injury.
Consider occupational and physical therapy consultations. Speech therapy should also be considered if language or speech is affected.
Society has a strong ethical and financial obligation to reduce abusive head trauma as the preventable damage to children is significant, and the long-term financial costs to society are extensive.
Prevention of abusive head trauma focuses on reducing child abuse, maltreatment, and increasing education. This includes public service announcements, pamphlets, and brochures. Education is also focused on family resource centers and home visit programs; particularly in high-risk homes with young parents in living in poverty. These programs can include mental and social services. Before discharge from the hospital, new parents should be instructed in the danger of shaking a child. Healthcare providers in pediatric offices and the emergency department must be trained and educated in identify parents at high risk of infant abuse. Parents need to be taught coping skills how to deal with crying and the danger of shaking a baby with an undeveloped brain.
Abusive head trauma is a preventable problem and a major societal challenge. Two national health initiatives are described below.
The Period of PURPLE Crying program is focused on education concerning normal infant behaviors, such as crying, that can frustrate caregivers. PURPLE stands for Peak (crying peaks at about 2 months, then decreases), Unpredictable, Resistant (to any soothing), Painlike (look on face), Long (bouts of crying), and Evening (most common time of crying).
The National Center on Shaken Baby Syndrome targets new and future parents. The organization attempts to increase skills and confidence as parents.
Healthcare providers can impact the incidence of abusive head trauma by educating caretakers on the dangers of shaking an infant. Prevention should be stressed in all encounters with families. Abusive head trauma syndrome education materials are available through several organizations such as the American Academy of Pediatrics, the National Center on Shaken Baby Syndrome, and Prevent Child Abuse America.
Prevention is the key; all providers of health care must work together to educate the public. Incessant crying is the major trigger of abusive head trauma. Recognition and education of high-risk caregivers will lower the incidence of pediatric abusive head trauma.
Child abusive head trauma and child abuse are public health problems that lead to lifelong health consequences, both physically and psychologically. Physically, those who undergo abusive head trauma may have neurologic deficits, developmental delays, cerebral palsy, and other forms of disability. Psychologically, child abuse victims tend to have higher rates of depression, conduct disorder, and substance abuse. Academically, these children may have poor performance at school with decreased cognitive function. Every healthcare professional has a responsibility both legally and ethically in identifying cases of child abuse.
Due to the frequency, negative impact on infants and children, and expense to society, it is imperative that clinicians become proficient in recognizing the signs and symptoms of abusive head injury. All health providers that evaluate children should be:
Clinicians that take care of infants and children should always remember:
While the diagnosis of abusive head trauma may sometimes be readily apparent, inexperienced and unsuspecting clinicians may fail to recognize injuries caused by child abuse. Further, when the diagnosis is not clear-cut, the clinician must exercise restraint until the evaluation is complete.