Introduction

Abusive head trauma (AHT) is the most severe form of injury to the nervous system on newborn and infants and may lead to permanent impairment of the immature brain, particularly vulnerable to hypoxic-ischemic and diffuse axonal injury. The incidence of AHT during the first year of life ranges from 24.6 to 38 per 100,000 person-years [1,2,3,4] and the mortality rate may reach 35% [4]. In addition, the incidence of disabilities was estimated in about 70% at 5 years post-injury [5]. These figures can be even more eloquent if one considers that many cases are unreported. AHT is a diagnosis of exclusion and the recognition of diseases that can mimic abusive trauma is of fundamental importance for neurosurgeons and pediatricians. The authors report, through two cases, different presentations that can lead to the suspicion of AHT and how to differentiate them from accidental trauma.

Case 1

A 9-month-old boy was taken to the emergency room by his young mother and her unemployed boyfriend. According to her, the boy fell out of the crib, cried inconsolably, and was only taken to a nearby emergency hospital a few hours later, after vomiting and presenting a generalized seizure. At admission, he was rated 11 on the pediatric GCS, was pale, had a bilateral subgaleal hematoma, and had bruises in the left parietal region and the neck. No retinal hemorrhage was reported.

A non-enhanced cranial CT scan with reconstruction showed several cranial fractures, including a depressed one on the right and a diastatic involving the sagittal and coronal sutures on the left, being the last in continuity with a hemorrhagic contusion in the frontal lobe (Fig. 1). Old posterior rib fractures were found at the lower thoracic cage on the right. No long bone fractures were noticed. On suspicion of abuse, the case was referred to the police authorities, and the mother ultimately confessed that her boyfriend had repeatedly hit the boy’s head against a wall. After stabilization of the clinical conditions, the patient underwent a repair of the dura mater, elevation skull fracture, and treatment of the orthopedic condition, being discharged 11 days later.

Fig. 1
figure 1

Case 1: a non-enhanced cranial CT with reconstruction showing voluminous and extensive subgaleal hematoma, depressed right parietal fracture (arrows in A and C), diastatic fracture in continuity with a hemorrhagic contusion in the left frontal lobe (arrow in B), another diastatic fracture involving the sagittal and coronal sutures on the left side (double arrow in C), surgical aspect (asterisk in D)

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Case 2

A 5-month-old girl was taken to the emergency room by her parents due to traumatic brain injury after falling from the bed. The mother was in postpartum depression and was alone at home with her two children. The delivery history was not atypical and there was no family history of hematological diseases.

A CT scan was performed and showed perimedullary subarachnoid hemorrhage (Fig. 2). The child was hypoactive, but responsive and after conservative treatment for 1 week showed clinical improvement. MRI did not show other lesions. Upon investigation, fundoscopy was performed and was normal. Long bone X-rays were normal. Therefore, the mother underwent psychological monitoring, but no inappropriate family behavior was identified. In the absence of signs of aggression, a hematological investigation was performed, and the infant was diagnosed with type 1 Von Willebrand’s disease, justifying the atypical bleeding and excluding the hypothesis of aggression.

Fig. 2
figure 2

Case 2: axial and sagittal CT scan showing perimedullar hemorrhage (arrows)

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Discussion

Pediatric abusive head trauma (AHT) involves injury to the skull or intracranial contents of infants or children younger than 5 years, caused by inflicted blunt impact, violent shaking, or both [6]. Earlier nomenclature included whiplash shaken infant syndrome, shaken impact syndrome, inflicted childhood neurotrauma, and shaken baby syndrome. The current term (AHT) was adopted by the American Academy of Pediatrics (AAP) in 2009 in recognition of the fact that head injury of children can involve a variety of biomechanical forces, including shaking, representing a complex medicolegal challenge [7, 8]. Compromise of the craniovertebral junction can also be associated.

The incidence of violent head trauma has been pointed out by recent studies carried out in Scotland, the USA, New Zealand, and Switzerland, ranging from 14.7 to 38.5 cases per 100,000 children, with the highest incidence for those under 1 year of age [6, 9,10,11,12]. It is noteworthy that, in the last survey carried out by the US Centers for Disease Control and Prevention, the incidence in the country was 0.76 fatal cases of AHT per 100,000 children up to 4 years of age, increasing to 2.14 when only children under 1 year of age were considered (6). In Brazil, there are still no studies that assess the real incidence of violent head trauma.

Although AHT often results in severe brain injury, the initial manifestations and neurologic status may be not recognized and even misinterpreted as “minor” trauma [13]. The clinical presentation can be wide and variable, but generally the cause–effect relationship of the trauma mechanism is poorly established. As we notice in the first case, the reported trauma history—a fall from a crib—was incompatible with the severity of the clinical findings and images obtained on admission.

Also, as in this case, perpetrators are often within the household, and the biological father is the aggressor in more than half of the cases, followed by a stepparent, and less frequently by the mother or both parents [14, 15]. The aggressor is usually a young male of low education and economic level, a member of a dysfunctional family, single or divorced, and a victim of parental violence as a child [16, 17]. Part or not of the family, perpetrators are usually emotionally immature and unable to cope with stressful situations such as crying, probably the most potent driving force in this setting. However, overt or latent, psychopathologies cannot be excluded as risk factors.

AHT is multifactorial, and at least one previous episode of shaking was admitted by family members in case 1, during the investigation. Therefore, it is not an isolated event, and there is a tendency to be repetitive with an increasing pattern of violence [1, 18]. A report in the literature describes that more than 25% of patients who are victims of AHT had sentinel symptoms not diagnosed by physicians, with bruises being the most common signs [19]. Bruising on the body are important warning signs and are known as “TEN-4” bruising (bruising of the torso, ears, and neck in children younger than 4 years or any bruising in an infant younger than 4 months) [20, 21].

Regarding imaging features, the classic triad, although not pathognomonic, has a high positive predictive value and consists of subdural hemorrhage, retinal hemorrhage, and long bone fracture [22].

Educational actions aimed at parents of newborns before hospital discharge and guidance for caregivers during the first months of the baby’s life can reduce the first occurrence of AHT, especially when the dangers of shaking are emphasized [10, 23]. Likewise, knowledge of the crying pattern in the baby’s first months of life helps to prevent new episodes, mainly if crying is recognized and accepted as a typical behavior in normal infants [24, 25].

Although not specific, subdural hemorrhages (SDHs) in locations such as interhemispheric or infratentorial spaces are more commonly related to AHT than to accidental trauma [26]. However, posttraumatic SDH has been reported in hemophilia A, B, and C; von Willebrand’s disease; fibrinogen disorders; thrombocytopenia; platelet disorders; hemolytic disease of the newborn; and rarely in other factor deficiencies (VII and X) [27]. Anderst et al. [27] described spontaneous SDH in bleeding disorders as severe hemophilia A and B and, type 1 von Willebrand’s disease. Although rare, hematological diseases should be considered when other data are lacking, as reported in case 2, in which the patient did not present retinal hemorrhage, fractures, skin bruising, or other signs of aggression. The atypical location of the hemorrhage can be explained by the underlying hematologic disease. Differential diagnosis is extremely important in these cases, both to avoid underdiagnosing AHT and to prevent morbidity if a pre-existing hematological disease is misdiagnosed.

Neurosurgeons should be aware of diseases that can mimic AHT, such as osteogenesis imperfecta, birth-related injuries, benign enlargement of subarachnoid spaces, and vascular malformations [22].

Conclusion

Abusive head trauma in children can present in different ways and understanding the history, social context, trauma mechanism, adequate imaging, and laboratory findings is essential for an accurate diagnosis. The lack of correct diagnosis is as serious in AHT as in other life-threatening diseases. Conditions mimicking AHT must be ruled out.