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Introduction Abusive head trauma (AHT) is a relatively common cause of neurotrauma in young children. Incidence, long-term consequences, clinical findings and differential diagnosis have been described extensively in ‘Educational paper: Abusive head trauma, Part I: clinical aspects’ in this journal. After formulating a differential diagnosis, additional investigations have to be performed to confirm or rule out alternative diagnoses. Radiology is an important tool in describing the exact location and severity of the injury. It can also help in the detection of other abnormalities that can make the initial diagnosis more likely, e.g., when rib fractures are present, or it can make initial diagnosis less plausible, e.g., when underlying bone disease is detected. Furthermore, it can help in assessing a prognosis for the child, depending on the brain damage seen. The aim of this educational paper is to give the paediatrician, facing a possible case of AHT, a comprehensive overview on the significant role of radiology in establishing a correct diagnosis. We will present the clinical findings in AHT and how to discriminate between AHT and accidental injury or other pathologies. We will describe the value of conventional radiology (CR), cranial ultrasonography (CUS), computed tomography (CT) and magnetic resonance imaging (MRI) in imaging abnormalities in AHT. Furthermore, the importance of interpreting, reporting and communicating radiological findings will be addressed in both a clinical and forensic perspectives.

lue of conventional radiology (CR), cranial ultrasonography (CUS), computed tomography (CT) and magnetic resonance imaging (MRI) in imaging abnormalities in AHT. Furthermore, the importance of interpreting, reporting and communicating radiological findings will be addressed in both a clinical and forensic perspectives. Modalities Conventional radiology The role of conventional radiology (CR) in detecting child abuse and neglect (CAN) has recently been discussed in this journal [33]. A full skeletal survey should be performed in all children under the age of 2 years where AHT is part of the differential diagnosis. Its role in detecting AHT is threefold; first, it has a (limited) role in detecting injuries to the head, both fractures and intracranial pathology. A skull radiograph is obtained in order to detect possible fractures that are missed on CT because of their location in the plane of scanning. No specific type of skull fracture is pathognomonic for child abuse. The majority of all skull fractures, both accidental and abusive, are linear fractures [8] (Fig. 1). As linear fractures can occur after a short distance fall (e.g., fall from arm of caretaker or fall from stairs, two accidents commonly described by caretakers in case of suspicion of AHT), these are not sensitive for AHT.Fig. 1 A four-month-old boy with a linear skull fracture (arrow) after a 80 cm high fall on a hard surface

r fractures can occur after a short distance fall (e.g., fall from arm of caretaker or fall from stairs, two accidents commonly described by caretakers in case of suspicion of AHT), these are not sensitive for AHT.Fig. 1 A four-month-old boy with a linear skull fracture (arrow) after a 80 cm high fall on a hard surface Bilateral fractures, multiple fractures, depressed fractures, fractures with diastases >3 mm of the fracture lines or occipital fractures are more commonly seen in child abuse [22, 24, 25]. A rare complication of a skull fracture is a growing skull fracture or progressive diastasis of the fracture line. They mostly occur after serious head trauma and child abuse is the most likely cause [8]. As in a growing skull fracture, there is nearly always brain damage, treatment is surgical and meant to reduce herniated brain tissue and repair injury to dura and skull [8]. As skull fractures heal without callus formation, dating of the accident based on the radiological skull findings is not possible. Therefore, in follow-up skeletal surveys, the radiographs of the skull should be omitted [8].

is surgical and meant to reduce herniated brain tissue and repair injury to dura and skull [8]. As skull fractures heal without callus formation, dating of the accident based on the radiological skull findings is not possible. Therefore, in follow-up skeletal surveys, the radiographs of the skull should be omitted [8]. Secondly, the skull radiograph can be supportive in demonstrating or excluding underlying disease, e.g., wormian bones in osteogenesis imperfecta and Menke’s disease [3, 19]. Thirdly, an important role for CR is imaging the rest of the skeleton, which can be very informative on abnormalities in the skeleton that support diagnosis leading to an increased risk in bone fragility, or can reveal occult fractures supporting the diagnosis of CAN (Fig. 2a, b, c). For this purpose, it is of major importance that the skeletal survey is performed according to international guidelines [4, 31].Fig. 2 a A two-month-old girl admitted because of abusive head trauma. The CT obtained at admission shows an overall decrease in density of brain tissue and a lack of grey–white matter differentiation. This is a sign of severe hypoxia of the brain and has a poor prognosis. b The skeletal survey shows a metaphyseal corner fracture of the distal tibia. This, in combination with the intracranial trauma, is highly indicative of abusive head trauma. c Five weeks after the initial CT scan, the girl has developed extensive diffuse multicystic encephalomalacia No specific type of skull fracture is pathognomonic for child abuse.

Secondly, the skull radiograph can be supportive in demonstrating or excluding underlying disease, e.g., wormian bones in osteogenesis imperfecta and Menke’s disease [3, 19]. Thirdly, an important role for CR is imaging the rest of the skeleton, which can be very informative on abnormalities in the skeleton that support diagnosis leading to an increased risk in bone fragility, or can reveal occult fractures supporting the diagnosis of CAN (Fig. 2a, b, c). For this purpose, it is of major importance that the skeletal survey is performed according to international guidelines [4, 31].Fig. 2 a A two-month-old girl admitted because of abusive head trauma. The CT obtained at admission shows an overall decrease in density of brain tissue and a lack of grey–white matter differentiation. This is a sign of severe hypoxia of the brain and has a poor prognosis. b The skeletal survey shows a metaphyseal corner fracture of the distal tibia. This, in combination with the intracranial trauma, is highly indicative of abusive head trauma. c Five weeks after the initial CT scan, the girl has developed extensive diffuse multicystic encephalomalacia No specific type of skull fracture is pathognomonic for child abuse. Cranial ultrasonography The use of cranial ultrasonography (CUS) is not primarily indicated in establishing the diagnosis of AHT. It can, however, be used in some cases for the follow up of intracranial pathology. The penumbra (from the Latin paene “almost, nearly” and umbra “shadow”) effect makes it hard to visualise the parts of the brain located just under the convexity of the skull. These places can harbour a subdural haematoma as a result of abuse but may be overlooked with CUS. With respect to sub-arachnoid haemorrhage, the sensitivity of CUS is inadequate for clinical use.

and umbra “shadow”) effect makes it hard to visualise the parts of the brain located just under the convexity of the skull. These places can harbour a subdural haematoma as a result of abuse but may be overlooked with CUS. With respect to sub-arachnoid haemorrhage, the sensitivity of CUS is inadequate for clinical use. CUS is applied in children with an increased head circumference, where a diagnosis of benign enlargement of the sub-arachnoid space (BESS) is suspected. BESS is diagnosed in children with a rapidly growing head, enlarged sub-arachnoid spaces and normal or only slightly enlarged ventricles. BESS is a self-limiting condition that needs no intervention in most children. The aetiology is unknown, but there seems to be a hereditary component as approximately 40% of children with BESS has a family member with a large head [35].

ead, enlarged sub-arachnoid spaces and normal or only slightly enlarged ventricles. BESS is a self-limiting condition that needs no intervention in most children. The aetiology is unknown, but there seems to be a hereditary component as approximately 40% of children with BESS has a family member with a large head [35]. With the use of a high frequency linear transducer, the sub-arachnoid space can be evaluated at the level of the frontal fontanel. The upper level of the width of the sub-arachnoid space varies in various publications but in general 4–5 mm is used as a cutoff level from normal. BESS is a known risk factor for SDH's after minimal or no head injury [35]. On colour Doppler CUS, a sign to look for are the crossing vessels, anchor veins in the sub-arachnoid space. This makes differentiation between BESS and a subdural haematoma possible [11, 23]. In children referred for an increase of head circumference, occasionally subdural haematomas can be diagnosed. In these cases, the crossing vessels will not be visible in the subdural collection, in many cases the border between the subdural and sub-arachnoid space will be visible (Fig. 3).Fig. 3 Cranial ultrasound of a four-month-old boy with a subdural collection due to BESS Once diagnosed, a SDH can be evaluated over time with CUS.The use of cranial ultrasonography (CUS) is not primarily indicated in establishing the diagnosis of AHT.

With the use of a high frequency linear transducer, the sub-arachnoid space can be evaluated at the level of the frontal fontanel. The upper level of the width of the sub-arachnoid space varies in various publications but in general 4–5 mm is used as a cutoff level from normal. BESS is a known risk factor for SDH's after minimal or no head injury [35]. On colour Doppler CUS, a sign to look for are the crossing vessels, anchor veins in the sub-arachnoid space. This makes differentiation between BESS and a subdural haematoma possible [11, 23]. In children referred for an increase of head circumference, occasionally subdural haematomas can be diagnosed. In these cases, the crossing vessels will not be visible in the subdural collection, in many cases the border between the subdural and sub-arachnoid space will be visible (Fig. 3).Fig. 3 Cranial ultrasound of a four-month-old boy with a subdural collection due to BESS Once diagnosed, a SDH can be evaluated over time with CUS.The use of cranial ultrasonography (CUS) is not primarily indicated in establishing the diagnosis of AHT. Computed tomography Computed tomography (CT) is the method of first choice in imaging traumatic brain injury for both fractures and intracranial pathology. As CT is widely available and has short scan times, it is the most appropriate modality in the acute phase of neurotrauma to assess the need for neurosurgical intervention.

tomography Computed tomography (CT) is the method of first choice in imaging traumatic brain injury for both fractures and intracranial pathology. As CT is widely available and has short scan times, it is the most appropriate modality in the acute phase of neurotrauma to assess the need for neurosurgical intervention. Both a soft tissue setting and a bone setting should be performed. CT settings should be age adjusted in order to reduce the radiation burden to a minimum (more information regarding dose reduction can be found in the website of the ‘Image Gently campaign’ [30]). Standard 3-D reconstructions are highly advisable to provide insight into the relationship between fractures that can be useful to explain possible trauma mechanisms to nonmedical personnel (Fig. 4a). Non-contrast-enhanced CT has a high sensitivity for detecting acute haemorrhage and midline shift (Fig. 5). It is less sensitive for the detection of non-haemorrhagic injuries, especially in the acute phase. In the setting of cranial trauma or AHT, there is no need for contrast-enhanced studies.Fig. 4 a A three-dimensional shaded surface display (3D-SSD) of a skull fracture in a six-week-old boy with no history of trauma. The 3D-SSD images can be used to display the lesions to lay persons, e.g., parents or in court. These images should always be interpreted in combination with the original axial source data in order not to miss small lesions, which can be obscured in the rendering process, giving false negative results. b CT shows a relative high density of the basal ganglia known as the reversal sign. This finding is a sign of diffuse, anoxic/ischaemic cerebral injury and carries a poor prognosis

iginal axial source data in order not to miss small lesions, which can be obscured in the rendering process, giving false negative results. b CT shows a relative high density of the basal ganglia known as the reversal sign. This finding is a sign of diffuse, anoxic/ischaemic cerebral injury and carries a poor prognosis Fig. 5 A three-year-old boy with a right-sided subdural haematoma (arrow) and a shift of the midline as a result of this subdural haematoma. Note the decrease in density of the white matter on the right side and the asymmetry of the ventricles Subdural haemorrhage is seen on CT in 77–89% of the cases with AHT [15, 29]. However, in autopsy studies, SDH’s have been described in approximately 83–90% of all cases [10, 14]. Subdural haemorrhage as well as sub-arachnoidal and epidural haemorrhage are seen in both AHT and after accidental trauma and are therefore not discriminating factors. Epidural haemorrhage is suggestive for impact trauma.

ever, in autopsy studies, SDH’s have been described in approximately 83–90% of all cases [10, 14]. Subdural haemorrhage as well as sub-arachnoidal and epidural haemorrhage are seen in both AHT and after accidental trauma and are therefore not discriminating factors. Epidural haemorrhage is suggestive for impact trauma. CT of the head should be performed in all children who present with signs of abuse in combination with signs of possible neurotrauma or intraocular haemorrhages. Routine cranial CT in all physically abused children without signs of AHT or neurotrauma is controversial. Literature is not conclusive about the additional value of CT in these children. The Royal College of Paediatrics and Child Health (RCPCH) and the Royal College of Radiologists (RCR) state that CT is indicated in ‘any child under the age of one (year) where there is evidence of abuse’ [31]. The American College of Radiologists, however, states that cranial CT in children without neurological symptoms is indicated only for those patients that are at ‘high risk’ for having suffered from AHT, e.g., children with rib fractures, multiple fractures, facial injury or children younger than 6 months of age [26].

. The American College of Radiologists, however, states that cranial CT in children without neurological symptoms is indicated only for those patients that are at ‘high risk’ for having suffered from AHT, e.g., children with rib fractures, multiple fractures, facial injury or children younger than 6 months of age [26]. The long-term effects of ionizing radiation cannot be used as a counterargument for performing a cranial CT because missing the diagnosis of AHT can have severe, even lethal, consequences.Computed tomography (CT) is the method of first choice in imaging traumatic brain injury for both fractures and intracranial pathology. As CT is widely available and has short scan times, it is the most appropriate modality in the acute phase of neurotrauma to assess the need for neurosurgical intervention.

onsequences.Computed tomography (CT) is the method of first choice in imaging traumatic brain injury for both fractures and intracranial pathology. As CT is widely available and has short scan times, it is the most appropriate modality in the acute phase of neurotrauma to assess the need for neurosurgical intervention. Magnetic resonance imaging MRI is not the first imaging tool in suspected traumatic brain injury. The most important reason is a lower sensitivity for acute haemorrhage compared to CT. Secondly, the long scan time makes it more difficult to perform successfully in children, unless general anaesthesia is used. This requires MR-compatible anaesthesia equipment, transferring a sometimes instable patient for a longer time from a paediatric ward to the radiology department and the presence of a doctor responsible for the anaesthesia. The last mentioned demands strict arrangements between pediatricians and radiologists about responsibilities for the sedated patient. Although no international MRI guidelines exist, the Royal College of Radiologists and the Royal College of Paediatrics and Child Health from the UK have developed a protocol, which consists of standard sequences T1- and T2-weighted imaging combined with two advanced techniques, namely susceptibility weighted imaging (SWI) and diffusion weighted imaging (DWI) [31].

, the Royal College of Radiologists and the Royal College of Paediatrics and Child Health from the UK have developed a protocol, which consists of standard sequences T1- and T2-weighted imaging combined with two advanced techniques, namely susceptibility weighted imaging (SWI) and diffusion weighted imaging (DWI) [31]. SWI is a technique originally developed for the analysis of small vessels and the detection of small brain tumours. This MRI technique exploits the susceptibility differences between tissues and uses the phase image to detect these differences. The application of this technique yields an enhanced contrast magnitude image which is sensitive to venous blood, haemorrhage and iron deposits [2, 27]. The high sensitivity for small haemorrhages is useful in cases of suspected AHT and it has been shown that the addition of SWI sequences to the standard MRI protocol enhances detection of haemorrhagic brain lesions, such as can be seen in diffuse axonal injury [32]. The extent and number of the micro-haemorrhages detected with SWI has been shown to correlate with a poor long-term outcome in children with AHT [5, 6, 12].

hat the addition of SWI sequences to the standard MRI protocol enhances detection of haemorrhagic brain lesions, such as can be seen in diffuse axonal injury [32]. The extent and number of the micro-haemorrhages detected with SWI has been shown to correlate with a poor long-term outcome in children with AHT [5, 6, 12]. DWI plays a key role in imaging of traumatic brain injury, especially in the assessment of changes after a hypoxic event such as stroke or AHT. In daily practice, it is the standard in stroke imaging. In DWI, each pixel on the MR image represents the rate of water diffusion, i.e., it displays the measurement of the Brownian motion of hydrogen atoms. If the diffusion is restricted, e.g., in the case of cytotoxic oedema resulting from an ischaemic event, then the affected area will have increased signal intensity on the DWI images. On the apparent diffusion coefficient images, which always complement the DWI study, the same area will have low signal intensity. Previous studies have shown that restricted diffusion correlates with poor outcome [7, 17, 28] (Fig. 4b, c). In cases of suspected AHT, DWI, as SWI, should always be performed [21].

images. On the apparent diffusion coefficient images, which always complement the DWI study, the same area will have low signal intensity. Previous studies have shown that restricted diffusion correlates with poor outcome [7, 17, 28] (Fig. 4b, c). In cases of suspected AHT, DWI, as SWI, should always be performed [21]. Approach Imaging strategy Kemp et al. performed a systematic review to determine the optimal imaging strategy to identify AHT [21]. As initial CT is widely accepted as modality of first choice in an acutely ill child with neurological symptoms, they included studies that compared additional MRI, follow-up CT and CUS with initial CT. Additional MRI revealed new information in at least 25% of all children with abnormalities on the initial CT scan. Additional findings detected by MRI were a.o. further SDH’s, sub-arachnoid haemorrhages, cranial shearing, ischaemia, infarction, parenchymal haemorrhages and cerebral contusions. DWI, a relatively new MRI technique described above, demonstrated more extensive injury than could be seen on normal MRI, correlated with poor outcome (Fig. 6a–f). The question whether children with no abnormalities on CT should undergo MRI cannot sufficiently be answered from the literature. The authors did find some studies that described children that had abnormalities on MRI in the presence of a normal CT, but study quality was too low to include these studies in the review. The role of repeat CT if early MRI was performed remains unclear from today’s literature. Studies on high resolution CUS described only 21 children who had CUS in total, but CUS failed to identify abnormalities in six cases. It can be concluded that there is evidence that the most solid way to identify intracranial injuries as a result of AHT is to perform initial CT. If CT is abnormal, early MRI including DWI should be performed. The role of MRI, if initial CT is normal, is unclear as is the role of repeat CT if early MRI is performed.Fig. 6 a A two-year-old girl with a subdural haematoma along the left convexity (arrow) and diffuse ischaemia (asterisk) as a result of abusive head trauma. b Diffusion-weighted MRI, obtained on the same day as the MRI, shows extensive temporoparietal cytotoxic oedema as a result of disturbed perfusion (restricted diffusion). c Diffusion-weighted MRI (apparent diffusion coefficient) shows a corresponding decrease in signal intensity. d Blood clot in the subdural haematoma shown on the FLuid Attenuation Inversion Recovery (FLAIR) image.

hows extensive temporoparietal cytotoxic oedema as a result of disturbed perfusion (restricted diffusion). c Diffusion-weighted MRI (apparent diffusion coefficient) shows a corresponding decrease in signal intensity. d Blood clot in the subdural haematoma shown on the FLuid Attenuation Inversion Recovery (FLAIR) image. This sequence uses a long TI in order to suppress the effect of fluid on the images. It can be used to show lesions that are normally obscured by the high signal intensity of fluid. e Chest radiographs obtained 3 weeks after the incident shows a consolidating posterior ribfracture (see insert). This was not visible on the initial skeletal survey and this shows the importance of a repeat skeletal survey in case of inconclusive findings. f MRI obtained after 2 months of the incident shows extensive diffuse multicystic encephalomalacia and bilateral subdural hygromas (asterisk)

osterior ribfracture (see insert). This was not visible on the initial skeletal survey and this shows the importance of a repeat skeletal survey in case of inconclusive findings. f MRI obtained after 2 months of the incident shows extensive diffuse multicystic encephalomalacia and bilateral subdural hygromas (asterisk) Dating haemorrhages Dating injuries can be very important to relate radiological findings to the trauma described. In court, this topic is extremely important as it will be of great value to relate the injuries to possible perpetrators that had had contact with the child. However, the scientific basis for unconditional statements on dating intracranial pathology based on radiological findings only is not validated. Current knowledge on dating SDH's is primarily based on two studies [34]. These studies, however, were performed in adults suffering from conditions different from AHT and exact timing of the incident was not always known [16, 18]. In a clinical setting, the generally accepted theory that acute haemorrhage SDH is hyperdense and that older haemorrhage is hypodense on CT is sufficient as are the temporal changes that have been described on MRI. In the setting of AHT, where a legal procedure is likely to occur, this knowledge is not solid enough. In a study where 29 cases of AHT with a confessing perpetrator were analysed, in more than half of the cases, the shaking was repetitive in a period of weeks or even months. No relation between repetitive shaking and SDH densities was found [1]. Vinchon et al. tried to develop a time scale model for SDH’s in children by performing repeat CT and MRI, but their group consisted of 20 children only. Furthermore, there was an overlap between the different time phases, so no firm conclusions can be drawn from their model [34].In a clinical setting, dating SDH on CT and/or MRI is common practice. In the setting of AHT, where a legal procedure is likely to occur, this practice has not been validated sufficiently.

nly. Furthermore, there was an overlap between the different time phases, so no firm conclusions can be drawn from their model [34].In a clinical setting, dating SDH on CT and/or MRI is common practice. In the setting of AHT, where a legal procedure is likely to occur, this practice has not been validated sufficiently. Interpretation and reporting Interpretation of imaging in case of suspected AHT cannot be done without access to complete clinical information. The radiologist should be informed on the trauma mechanism described by caregivers, in order to be able to assess whether this is a plausible explanation for the abnormalities or not. A suspicion of AHT arising from radiological imaging should be communicated with the clinician immediately to ensure the child’s safety while other additional investigations can be performed. The final diagnosis of AHT can never be based solely on radiological findings. Other additional findings, medical history, growth curve and risk factors for child abuse all have to be taken into account in relation with the trauma described by caregivers.Interpretation of imaging in case of suspected AHT cannot be done without access to complete clinical information.

ely on radiological findings. Other additional findings, medical history, growth curve and risk factors for child abuse all have to be taken into account in relation with the trauma described by caregivers.Interpretation of imaging in case of suspected AHT cannot be done without access to complete clinical information. A multidisciplinary child abuse and neglect team (CAT) should collect these data and advice the clinician. It is of great value that a (pediatric) radiologist is part of the CAT. Although radiological findings are only part of an extensive workup combining many findings, the radiologist should be aware that radiological findings, and therefore his/her report, can be crucial in the decision to establish the diagnosis of AHT [13, 20]. It is not uncommon that the radiological report becomes part of legal proceedings. It is, therefore, essential that the report is objective and that it reflects the level of uncertainty as it is reported in medical literature [9]. The report should state the quality of the study, and in case of the skeletal survey, if performed according to international guidelines. The reporting radiologist should have experience in paediatric radiology and child abuse. In case of doubt, an expert in child abuse should be consulted.A multidisciplinary child abuse and neglect team (CAT) should collect all patient data and advice the clinician. It is of great value if a (paediatric) radiologist is part of the CAT.

diologist should have experience in paediatric radiology and child abuse. In case of doubt, an expert in child abuse should be consulted.A multidisciplinary child abuse and neglect team (CAT) should collect all patient data and advice the clinician. It is of great value if a (paediatric) radiologist is part of the CAT. Conclusion AHT is a relatively common cause of neurotrauma in young children with severe consequences. Imaging has an important role in establishing the diagnosis and assessing the prognosis. CT, followed by MRI including DWI, is the best tool for neuroimaging. There is no evidence-based approach for the follow-up of AHT, both repeat CT and MRI are currently used but literature is not conclusive. A full skeletal survey according to international guidelines should always be performed to obtain information on possible underlying bone diseases or injuries suspicious for child abuse. Communication between radiologists and clinicians is extremely important. If there is a suspicion of AHT, this should be communicated with the clinicians immediately in order to arrange protective measures as long as AHT is part of the differential diagnosis. The final diagnosis of AHT can never be based on radiological findings only; this should always be made in a multidisciplinary Child Abuse and Neglect Team where all clinical and psychosocial information is combined and judged by a group of experts in the field.

Conclusion AHT is a relatively common cause of neurotrauma in young children with severe consequences. Imaging has an important role in establishing the diagnosis and assessing the prognosis. CT, followed by MRI including DWI, is the best tool for neuroimaging. There is no evidence-based approach for the follow-up of AHT, both repeat CT and MRI are currently used but literature is not conclusive. A full skeletal survey according to international guidelines should always be performed to obtain information on possible underlying bone diseases or injuries suspicious for child abuse. Communication between radiologists and clinicians is extremely important. If there is a suspicion of AHT, this should be communicated with the clinicians immediately in order to arrange protective measures as long as AHT is part of the differential diagnosis. The final diagnosis of AHT can never be based on radiological findings only; this should always be made in a multidisciplinary Child Abuse and Neglect Team where all clinical and psychosocial information is combined and judged by a group of experts in the field. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. B. Spivack is an indepent working child abuse expert.

Introduction With an estimated incidence of 14–40 per 100,000 children under the age of 1 Abusive Head Trauma (AHT) is probably as prevalent in young children as neonatal meningitis (25–32 per 100,000 live births [21,36,44]) and lymphatic leukaemia (28.7–36.6 per 100,000 children <1 [23]). Still, clinicians feel uncomfortable establishing the diagnosis and performing the right additional investigations. The term ‘Abusive Head Trauma’ is recommended by the American Academy of Pediatrics (AAP) for the combination of findings formerly described as shaken baby syndrome [9]. It has, among other things, also been described as Inflicted Traumatic Brain Injury (ITBI), Non-Accidental Head Injury (NAHI) and whiplash shaken infant syndrome. AHT can present with cerebral, cervical or cranial injuries that result from inflicted head injury, which can be shaking, impact trauma or a combination of both. The term ‘shaken baby syndrome’ implies the underlying mechanism has to be shaking. Although shaking can cause severe head injury, in some of these children there also has been impact trauma or a combination of shaking and impact. Therefore, the AAP recommends using Abusive Head Trauma, a term that does not refer to the exact accident mechanism (shaking) but to the harming action in broader perspective (abuse).

haking can cause severe head injury, in some of these children there also has been impact trauma or a combination of shaking and impact. Therefore, the AAP recommends using Abusive Head Trauma, a term that does not refer to the exact accident mechanism (shaking) but to the harming action in broader perspective (abuse). The aim of this educational paper is to give the paediatrician, facing a possible case of AHT, a comprehensive overview of the clinical findings and differential diagnoses. The role of radiology in establishing the diagnosis of AHT will be discussed later in this journal, in ‘Educational paper: Abusive head trauma, Part II: Radiological aspects’.

paper is to give the paediatrician, facing a possible case of AHT, a comprehensive overview of the clinical findings and differential diagnoses. The role of radiology in establishing the diagnosis of AHT will be discussed later in this journal, in ‘Educational paper: Abusive head trauma, Part II: Radiological aspects’. Incidence and consequences Incidence For several reasons it is difficult to determine the actual incidence of AHT. First of all, not all abused infants need/seek medical help and come in contact with the medical system. In a Dutch study among primary health care visitors, 5.6% of the parents of 6-month-old babies reported to have shaken, slapped or smothered their baby at least once [34]. In an American study, 2.6% of the children under the age of 2 years were reported by their mothers to have been shaken [38]. Most of these children do not need medical attention and are therefore not represented in incidence numbers. Secondly, not all cases presented in hospitals are recognised as cases of AHT. Abuse cases may be diagnosed with other conditions, e.g., accidental trauma or Sudden Infant Death Syndrome. Finally, different definitions for AHT are in use, making comparison of incidence rates reported by different institutions difficult.

econdly, not all cases presented in hospitals are recognised as cases of AHT. Abuse cases may be diagnosed with other conditions, e.g., accidental trauma or Sudden Infant Death Syndrome. Finally, different definitions for AHT are in use, making comparison of incidence rates reported by different institutions difficult. Several prospective studies have been performed to try to establish the incidence of AHT. Most of these studies collect data from both hospitals and (forensic) pathology departments. In the first population-based American study, an incidence of 29.7 per 100,000 person years was found for children under the age of 1 year [25]. In a Scottish study, the incidence of children with AHT, based on hospital visits, was 24.6 per 100,000 children younger than 1 year [1]. In British and Estonian studies, the incidence rates were 14.2 and 40.0 per 100,000 in children under the age of 1, respectively [20,37]. In a prospective Swiss study an incidence of 14 per 100,000 was found in children under the age of 6 years [17]. Most incidence studies describe a higher proportion of boys being affected; range 62–77% [1,17,20,25,37]. Most cases manifest before the age of 6 months; median age ranges from 2.2 to 5.9 months [1,17,20,25,37].AHT is as prevalent in very young children as other potential lethal diseases e.g. neonatal meningitis.

Several prospective studies have been performed to try to establish the incidence of AHT. Most of these studies collect data from both hospitals and (forensic) pathology departments. In the first population-based American study, an incidence of 29.7 per 100,000 person years was found for children under the age of 1 year [25]. In a Scottish study, the incidence of children with AHT, based on hospital visits, was 24.6 per 100,000 children younger than 1 year [1]. In British and Estonian studies, the incidence rates were 14.2 and 40.0 per 100,000 in children under the age of 1, respectively [20,37]. In a prospective Swiss study an incidence of 14 per 100,000 was found in children under the age of 6 years [17]. Most incidence studies describe a higher proportion of boys being affected; range 62–77% [1,17,20,25,37]. Most cases manifest before the age of 6 months; median age ranges from 2.2 to 5.9 months [1,17,20,25,37].AHT is as prevalent in very young children as other potential lethal diseases e.g. neonatal meningitis. Mortality According to Duhaime et al. [14], ‘trauma is the most common cause of death in childhood, and inflicted head injury is the most common cause of traumatic death in infancy’ [14]. Reported mortality rates for AHT in the studies mentioned above are quite similar: 15–23% of all recognised cases of AHT die before or shortly after presentation [17,20,25,37]. In the Scottish cohort, the mortality was lower than in other studies, namely 11% [2]. This is probably due to selection bias; studies including only patients admitted to a Paediatric Intensive Care Unit (PICU) will probably find worse outcomes than studies including patients with AHT from all hospital departments. The latter will probably be a better representative of mortality in the full spectrum of AHT. This means that although AHT accounts for a substantial number of paediatric deaths, it is not exactly known what percentage of the affected children die. Besides the short-term mortality, a significant amount of AHT survivors are severely handicapped and will have a lower life expectancy. Death in these children is unlikely to be registered as the result of AHT.

ubstantial number of paediatric deaths, it is not exactly known what percentage of the affected children die. Besides the short-term mortality, a significant amount of AHT survivors are severely handicapped and will have a lower life expectancy. Death in these children is unlikely to be registered as the result of AHT. Morbidity In the Swiss AHT follow-up study by Fanconi and Lips [17], only 36% of survivors had a good outcome, and 64% were disabled. Roughly half of these children were moderately disabled, e.g., had significant reduction in cognitive functioning, motor deficiencies, or were referred to outpatient rehabilitation therapy. The other half were severely disabled, e.g., had cognitive scores in the deficient range, severe motor deficits, or were referred to inpatient rehabilitation [17]. In the Scottish incidence study, the same distribution was found; roughly one-third had a good outcome, one-third were mildly to moderately disabled and one-third were severely disabled [2]. In a small sample of AHT survivors (only 14 of 62 AHT survivors could be contacted), Duhaime et al. [13] also found that 36% had a good outcome, 14% were moderately disabled and 50% were severely disabled or vegetative. Because of the young age of the patients and the prolonged developmental course of the brain, it has been said that the final neurological prognosis cannot be given before they reach school age. Bonnier et al. found that children who initially appear to be symptom-free can have neurological problems after this symptom-free interval [5]. Ewing-Cobbs et al. [16] found that nearly 50% of children with early traumatic brain injury (both AHT and other causes) had IQ’s below the 10th percentile.

ey reach school age. Bonnier et al. found that children who initially appear to be symptom-free can have neurological problems after this symptom-free interval [5]. Ewing-Cobbs et al. [16] found that nearly 50% of children with early traumatic brain injury (both AHT and other causes) had IQ’s below the 10th percentile. Recognising AHT Because of (relatively) common appearance and severe consequences, all paediatricians should be able to recognise AHT. Establishing the diagnosis AHT can be very difficult, especially if no fractures are found. In a retrospective study among children with AHT by Jenny et al. [24], 31% of abuse cases were not initially recognised. AHT was more likely to be unrecognized in very young children, white children, children from intact families and in children without respiratory problems or convulsions. The authors estimate that 80% of deaths in the missed AHT group could have been prevented by earlier recognition of abuse. In the majority of the cases of AHT, parents describe a relatively small trauma, e.g., fall from arms, or no preceding trauma at all [19]. Having knowledge about the expected range of injury seen following common accidents can be useful in differentiating between accidental and non accidental injury. Child abuse needs intervention; missing the diagnosis can have severe consequences for the patient and the siblings. On the other hand, wrongfully concluding that a child has been mistreated will have devastating effects on the family as well. It is therefore essential that, in each case of suspected AHT, a multidisciplinary approach is chosen. Paediatricians, radiologists, ophthalmologists, social workers and child protection workers have to work closely together, preferably in an institutional child abuse and neglect team (CAT), in order to collect as much information as possible on the facts that led to clinical manifestations. The clinical abnormalities found during physical examination have to be sorted out in detail in order to formulate an accurate differential diagnosis. It is of great importance that the right kind of additional investigation is performed to reach the right diagnosis.

le on the facts that led to clinical manifestations. The clinical abnormalities found during physical examination have to be sorted out in detail in order to formulate an accurate differential diagnosis. It is of great importance that the right kind of additional investigation is performed to reach the right diagnosis. Clinical findings and differential diagnosis As AHT is the most common cause of neurotrauma in children younger than 2 years, it should be considered in all children presenting with neurotrauma, unless the trauma is without any doubt accidental, e.g., a car accident.

le on the facts that led to clinical manifestations. The clinical abnormalities found during physical examination have to be sorted out in detail in order to formulate an accurate differential diagnosis. It is of great importance that the right kind of additional investigation is performed to reach the right diagnosis. Clinical findings and differential diagnosis As AHT is the most common cause of neurotrauma in children younger than 2 years, it should be considered in all children presenting with neurotrauma, unless the trauma is without any doubt accidental, e.g., a car accident. Clinical signs and symptoms seen in children with AHT depend of the type of AHT and accompanying injuries. Neurological manifestations include altered state of consciousness (77%), seizures (43–50%), vomiting (15%), and delayed development (12%) [20,37]. Subdural haemorrhages, described in 77–89% of the patients, are the most common neuroradiological finding [17,37] (Fig. 1). In autopsy series, subdural haematoma (SDHs) have been described in approximately 83–90% of all children diagnosed with AHT [6,12]. Other neuroradiological findings include subarachnoidal haemorrhages (12–25%), intracerebral haemorrhages (8%), epidural haemorrhage (4%), parenchyma lesions (37%), and hygroma (11%) [17,37]. In a systematic review by Maguire et al. [29], only apnoea was found to be a critical distinguishing feature for AHT compared to accidental head injury, having a positive predictive value (PPV) of 93%. Rib fractures and retinal haemorrhage were strongly associated with AHT, having a PPV of 73% and 71%, respectively. Though seizures are more common in AHT, this trend did not achieve statistical significance. Long bone fractures were not significantly discriminative, although the ‘classical metaphyseal lesion’ was not separated out in this analysis, and has been found to be highly correlated with abuse. Skull fracture and bruising on the head were more common in accidental injury, but this trend, too, did not achieve significance. Correlation between skull fractures and intracranial pathology is limited. Skull fractures can occur with and without intracranial bleeding. On the other hand, intracranial injury can be present without a skull fracture [4].Fig. 1 Two-month-old boy, victim of abusive head trauma. The CT shows an interhemispheric subdural haematoma along the falx cerebri. Subdural haematomas in children often extend along the falx cerebri and this should not be confused with calcification, which is seen at an older age

present without a skull fracture [4].Fig. 1 Two-month-old boy, victim of abusive head trauma. The CT shows an interhemispheric subdural haematoma along the falx cerebri. Subdural haematomas in children often extend along the falx cerebri and this should not be confused with calcification, which is seen at an older age In a recent systematic review on ocular signs in AHT intraocular haemorrhages were seen in 74% (range 51%–100%) of 560 combined cases of AHT and in 82% (range 63–100%) of cases in autopsy series [3]. Retinal haemorrhages are bilateral in 85% of AHT cases [27]. Injuries outside the head, e.g., bruises and fractures, are found in 35–54% and 33–48%, respectively [17,37]. This means that in a substantial number of AHT patients no other traumatic injuries are detected, although severe traumatic brain injury exists. The absence of fractures and bruises is therefore never an argument against AHT.As AHT is the most common cause of neurotrauma in children younger than 2 years, it should be considered in all children presenting with neurotrauma, unless the trauma is without any doubt accidental, e.g., a car accident. Skull fractures can occur with and without intracranial bleeding. On the other hand, intracranial injury can be present without a skull fracture. Minns and Busutill distinguish four different types of AHT [31]

In a recent systematic review on ocular signs in AHT intraocular haemorrhages were seen in 74% (range 51%–100%) of 560 combined cases of AHT and in 82% (range 63–100%) of cases in autopsy series [3]. Retinal haemorrhages are bilateral in 85% of AHT cases [27]. Injuries outside the head, e.g., bruises and fractures, are found in 35–54% and 33–48%, respectively [17,37]. This means that in a substantial number of AHT patients no other traumatic injuries are detected, although severe traumatic brain injury exists. The absence of fractures and bruises is therefore never an argument against AHT.As AHT is the most common cause of neurotrauma in children younger than 2 years, it should be considered in all children presenting with neurotrauma, unless the trauma is without any doubt accidental, e.g., a car accident. Skull fractures can occur with and without intracranial bleeding. On the other hand, intracranial injury can be present without a skull fracture. Minns and Busutill distinguish four different types of AHT [31] Hyperacute encephalopathy Approximately 6% of all children with AHT presents with this form of AHT in their study. These children are young at presentation (2–3 months of age) and present with acute respiratory failure and cerebral oedema; the majority of them are dead or die shortly after presentation. Hyperacute encephalopathy results from an injured brainstem after hyperflexion and hyperextension. At autopsy localised axonal damage at the craniocervical junction, in the corticospinal tracts, and in the cervical cord roots is seen, in combination with brain swelling and hypoxic injury.

ie shortly after presentation. Hyperacute encephalopathy results from an injured brainstem after hyperflexion and hyperextension. At autopsy localised axonal damage at the craniocervical junction, in the corticospinal tracts, and in the cervical cord roots is seen, in combination with brain swelling and hypoxic injury. Acute encephalopathy This is the most common form of AHT, affecting approximately 53% of cases, and has been described as the classic ‘shaken baby syndrome’. Children present with the findings mentioned above: a low level of consciousness, increased cranial pressure, convulsions, apnoea, hypotonia, anaemia, and/or shock. Trauma in body parts other than the brain are found in 35–54% of the cases [37]. The cause can be shaking injury, impact trauma or a combination of both. Extended injury is seen on MRI, with SDHs, oedema, contusions and lacerations and white matter shearing. Subacute non-encephalopathic presentation Approximately 19% of all patients presents with sub-acute non-encephalopathic AHT. This is a less severe form of acute encephalopathy. SDH’s and retinal haemorrhages are found, but other brain injuries are less recognisable. Coexistent injuries are common.

Acute encephalopathy This is the most common form of AHT, affecting approximately 53% of cases, and has been described as the classic ‘shaken baby syndrome’. Children present with the findings mentioned above: a low level of consciousness, increased cranial pressure, convulsions, apnoea, hypotonia, anaemia, and/or shock. Trauma in body parts other than the brain are found in 35–54% of the cases [37]. The cause can be shaking injury, impact trauma or a combination of both. Extended injury is seen on MRI, with SDHs, oedema, contusions and lacerations and white matter shearing. Subacute non-encephalopathic presentation Approximately 19% of all patients presents with sub-acute non-encephalopathic AHT. This is a less severe form of acute encephalopathy. SDH’s and retinal haemorrhages are found, but other brain injuries are less recognisable. Coexistent injuries are common. Chronic extra-cerebral presentation The chronic extra-cerebral form of AHT (22% of cases) is the hardest to relate to abuse because of the time interval between the incident, development of complaints and establishing a diagnosis. Children present with expanding head circumference and/or signs of raised intracranial pressure, e.g., irritability, vomiting, failure-to-thrive, hypotonicity or convulsions. An isolated subdural haemorrhage is often found, but retinal haemorrhages can have disappeared already. If other signs of abuse can be detected, e.g., rib fractures, it is easier to relate the SDH to abuse. If the SDH is the only sign, it is highly plausible that a trauma has happened, but limitation in the dating of SDHs makes conclusive diagnosis difficult.

found, but retinal haemorrhages can have disappeared already. If other signs of abuse can be detected, e.g., rib fractures, it is easier to relate the SDH to abuse. If the SDH is the only sign, it is highly plausible that a trauma has happened, but limitation in the dating of SDHs makes conclusive diagnosis difficult. AHT should be part of the differential diagnosis in children with a variety of non-neurologic presentations, such as increasing head circumference, children with failure-to-thrive, vomiting, crying excessively, poor drinking, developmental delay, children who present with other forms of physical abuse, and children with siblings who suffered severe physical abuse. Multiple factors contribute to the recognition and diagnosis of AHT. A major determination that must be made is whether the described trauma can explain the child’s injuries. The identification of other, often non-acute injuries can be of great importance to support the diagnosis of inflicted injury, although the absence of other traumatic injuries does not rule out AHT. The child’s past history can contribute to suspicion of inflicted injury. In one study approximately 20% of the children who died as a result of Child Abuse had had contact with the health care system in the month before their dead. Some of these presentations were suspicious for CAN and provided a missed opportunity for intervention [26]. Oral et al. [32] found that 8% of children who died of AHT had a medical history of abuse that was missed by health care providers.

use had had contact with the health care system in the month before their dead. Some of these presentations were suspicious for CAN and provided a missed opportunity for intervention [26]. Oral et al. [32] found that 8% of children who died of AHT had a medical history of abuse that was missed by health care providers. It is therefore of great importance that history taking be done very carefully and that information be gathered about not only this child and this event, but also about the lifelong, and family medical history [27]. Both parents and other health care professionals can give important information that can support or weaken the diagnosis of AHT. History taking should at least include the following: Detailed history Any reported trauma event should be made absolutely clear to the treating physician. If an accident is described, the doctor should exactly be aware of the timeline and exact circumstances of the incident, i.e., of which height the child fell, what material was on the floor, who was present, how the child reacted, what did the caregivers do at that moment, how many time elapsed between the incident and seeking medical help. If no accident was described but the child was found or suddenly appeared to be in a bad condition it should be clear what the first manifestations were: what was the last time the child was seen in good condition, how many time elapsed between this moment and the clinical symptoms.

e incident and seeking medical help. If no accident was described but the child was found or suddenly appeared to be in a bad condition it should be clear what the first manifestations were: what was the last time the child was seen in good condition, how many time elapsed between this moment and the clinical symptoms. Medical history The history should document prior presentations to any hospitals, to the GP, and to routine primary health care visits. Prior traumas or signs and symptoms attributable to injury must be sought out. Growth curve All former measurements should be retrieved to construct a growth curve. The growth curve of the skull is most important, as the first sign of deviation from the patient’s growth curve can indicate a possible event that led to an increase in head circumference. Medical history of siblings Unusual medical contacts of brothers and/or sisters may indicate a hereditary disorder or a history of family violence. Family known at Child Protection Services (CPS) Many children who present with AHT have a prior history with CPS. The team must determine if this child and/or siblings are known at the CPS, or if there are siblings placed in foster care.

Medical history of siblings Unusual medical contacts of brothers and/or sisters may indicate a hereditary disorder or a history of family violence. Family known at Child Protection Services (CPS) Many children who present with AHT have a prior history with CPS. The team must determine if this child and/or siblings are known at the CPS, or if there are siblings placed in foster care. Assessing risk factors In close collaboration with, e.g., a social worker an assessment of risk factors should be made (Table 1). AHT also occurs in families with little or no risk factors at all, but the presence of risk factors should increase the physicians’ awareness.AHT should be part of the differential diagnosis in children with a variety of nonneurologic presentations, such as increasing head circumference, children with failure-to-thrive, vomiting, crying excessively, poor drinking, developmental delay, children who present with other forms of physical abuse, and children with siblings who suffered severe physical abuse. Table 1 Risk factors for child abuse [41] Parents Environment Child Psychiatric problems Partner violence Ex-prematures Substance or alcohol abuse Large family Dysmatures Suffered from abuse in youth Stepchildren Physically disabled Lack of pedagogic capacity Poverty/financial problems Mentally disabled Very low level of education Residential instability Excessive crying Single parent Social isolation Chronically ill Young mother Refugee families Unwanted Unemployment Behavioural problems

ffered from abuse in youth Stepchildren Physically disabled Lack of pedagogic capacity Poverty/financial problems Mentally disabled Very low level of education Residential instability Excessive crying Single parent Social isolation Chronically ill Young mother Refugee families Unwanted Unemployment Behavioural problems Differential diagnosis Although AHT is the most common cause of SDH in children <1 year [30], the differential diagnosis of intracranial haemorrhage is extensive (Table 2, adapted from David) [10]. After formulating a differential diagnosis, additional investigations have to be performed to confirm or rule out alternative diagnoses. The role of imaging will be discussed in part II, to be published later in this journal. We will not address blood examination, ophthalmologic examination and genetic analysis for rare diseases.Table 2 Differential diagnosis of intracranial haemorrhage in children adapted from David [10]

rule out alternative diagnoses. The role of imaging will be discussed in part II, to be published later in this journal. We will not address blood examination, ophthalmologic examination and genetic analysis for rare diseases.Table 2 Differential diagnosis of intracranial haemorrhage in children adapted from David [10] Category Cause Non accidental trauma Shaking, impact or a combination Accidental trauma For example, falls, motor vehicle accident Medical and surgical interventions Known from the medical record Prenatal/perinatal conditions Birth trauma Intrauterine trauma, e.g., domestic violence to mother Idiopathic intrauterine subdural haematoma Intrauterine isoimmune thrombocytopaenic purpura Maternal pre-eclampsia Coagulation disorders Haemophilia A and B von Willebrand disease Factor V deficiency Factor XII deficiency Factor XIII deficiency Haemorrhagic disease of the newborn (vitamin K deficiency) Disseminated intravascular coagulation (DIC) Hermansky–Pudlak syndrome (albinism) Alpha 1-antitrypsin deficiency Congenital malformations Genetic disorders Osteogenesis imperfecta Sickle cell anaemia Alagille syndrome Ehlers–Danlos syndrome Menkes kinky hair syndrome Metabolic disorders Glutaric aciduria type 1 Pyruvate carboxylase deficiency Infectious disorders Meningitis Kawasaki disease Herpes simplex encephalitis Congenital toxoplasmosis Intoxication Lead poisoning Cocaine Anticoagulant therapy

le cell anaemia Alagille syndrome Ehlers–Danlos syndrome Menkes kinky hair syndrome Metabolic disorders Glutaric aciduria type 1 Pyruvate carboxylase deficiency Infectious disorders Meningitis Kawasaki disease Herpes simplex encephalitis Congenital toxoplasmosis Intoxication Lead poisoning Cocaine Anticoagulant therapy All medical conditions, both congenital and acquired, should be ruled out before trauma can be considered to cause the (combination of) findings. If trauma is the only option, it should be judged carefully whether accidental trauma is a possible explanation for the abnormalities found. If no accidental trauma has been described that can cause these findings this option is excluded as well and AHT is the only remaining diagnosis. Most diagnoses listed in this table can be ruled out easily because they should have been known from medical history (medical interventions, ingestion), are accompanied by other signs and symptoms (genetic disorders) or can be rejected after simple laboratory results (coagulation disorders, infectious disorders). Furthermore, all diseases listed above are extremely uncommon. Some groups of diagnoses are more likely to cause SDH’s, namely birth trauma, coagulation disorders, metabolic disorders and accidental trauma.

etic disorders) or can be rejected after simple laboratory results (coagulation disorders, infectious disorders). Furthermore, all diseases listed above are extremely uncommon. Some groups of diagnoses are more likely to cause SDH’s, namely birth trauma, coagulation disorders, metabolic disorders and accidental trauma. Birth trauma has been described as a common cause of SDH’s. In prospective studies, 10% to 46% of newborns without clinical signs or symptoms had SDH. All of these SDH’s were resolved after 4 weeks to 3 months [28,35,43]. These haematomas were differently located compared to SDH’s with clinical manifestations. Typically, they present as a thin film of blood occipital or infratentorial overlying the cerebellar hemispheres. It has been hypothesized that these clinically silent SDH’s may present with delayed symptoms due to catastrophic re-bleeding, or growing chronic SDH [10]. No studies except for case reports have demonstrated the existence of these categories. It is well known that some SDH’s present after birth with major clinical symptoms. These space-occupying SDH’s give immediate signs and symptoms post-partum, e.g., seizures, hypotonia and coma [10].

ing, or growing chronic SDH [10]. No studies except for case reports have demonstrated the existence of these categories. It is well known that some SDH’s present after birth with major clinical symptoms. These space-occupying SDH’s give immediate signs and symptoms post-partum, e.g., seizures, hypotonia and coma [10]. Coagulation disorders are an important alternative cause of intracranial haemorrhage in young children. It is uncommon for bleeding disorders to present with intracranial haemorrhage except for vitamin K deficiency [7,45]. It is mostly seen in breastfed babies who do not receive supplemental vitamin K. In some cases an underlying disease is present [15,33,40,42]. Although most Western countries have vitamin K guidelines [11], there is never a 100% adherence. It is important to note that an abnormal coagulation time can be caused by a large haemorrhage and does not necessarily reflect an underlying problem with coagulopathy [22]. Although certain genetic and metabolic disorders can cause SDHs, most of the affected children will show other features as well. These diseases are less common than AHT and the presence of a rare disease does not rule out child abuse. In children with SDH’s without signs of trauma, glutaric aciduria type 1 should be ruled out as children with glutaric aciduria type 1 can develop normally the first 6–18 months of life [18].AHT is the most common cause of SDH’s in young children.

an AHT and the presence of a rare disease does not rule out child abuse. In children with SDH’s without signs of trauma, glutaric aciduria type 1 should be ruled out as children with glutaric aciduria type 1 can develop normally the first 6–18 months of life [18].AHT is the most common cause of SDH’s in young children. Falls from limited height and AHT An extensive overview of literature on short-distance falls and accompanying injuries has been provided in ‘Forensic Aspects of Pediatric Fractures’ [4]. Short distance falls (<1.5 m.) usually take place from a couch, crib or caregivers arms. Eight studies describe 3451 children who experienced a short distance fall. Child abuse was highly unlikely in most studies, e.g., because only falls during hospital admissions were included. In 25 of these children (0.7%), a skull fracture was found. Skull fractures were never seen after a fall from a couch. It has to be noted that not all children underwent (skull) radiography, so fractures without clinical signs or symptoms could have been missed. No life-threatening events or intracranial pathology have been reported in these types of falls. Serious intracranial injuries and fatalities have been reported after a fall from a baby walker and perambulator. Literature is not conclusive on potential serious or lethal consequences after falls from baby bouncers, bunk beds, high chairs, staircases, shopping trolleys and trampolines. Very few studies have been published on these specific subjects. It is clear that falls are very common in young children; about 50% of all children will experience a short distance fall in the first year of life. It has been calculated that approximately 1 in 250,000 children <1 year will die from a short-distance fall. Another literature study found that the population based risk of dying after a short distance fall for young children is less than 1 per million per young children per year [8].

e fall in the first year of life. It has been calculated that approximately 1 in 250,000 children <1 year will die from a short-distance fall. Another literature study found that the population based risk of dying after a short distance fall for young children is less than 1 per million per young children per year [8]. As (intra)cranial pathology is a necessary condition for AHT, this is described in all studies on AHT. As mentioned before injuries other than intracranial pathology, e.g., fractures, are found in approximately 40% of all cases. The only diagnoses, in the differential, that cause both intracranial haemorrhage and fractures are severe accidents like motor vehicle accidents, and osteogenesis imperfecta [39]. As a result the combination of these findings is highly suggestive for AHT (Fig. 2a, b). More difficult are the cases where intracranial pathology is the only abnormal finding. AHT is the most common cause of SDHs in young children, but in absence of any other signs of trauma establishing the diagnosis is more difficult for clinicians. Of all neurologic symptoms, only apnoea has been found to be a critical distinguishing feature for AHT compared to accidental head trauma. After ruling out underlying disease with relatively simple additional investigations, history taking, including all the items mentioned above, is of great diagnostic value. A presenting history of no or low-impact trauma has a specificity of 0.97 and a PPV of 0.92 for AHT. In patients with neurological symptoms at discharge, no or low-impact trauma histories’ specificity and PPV are both 1.0 for AHT. In the same study injuries were blamed on resuscitation in 12% of AHT cases compared to 0% in not definite abuse cases. The initial history of trauma described by caregivers was changed in 9% of definite AHT cases compared to 0% in not definite abuse cases [19].Fig. 2 a Four-month-old boy admitted with a large subdural haematoma with clinical symptoms. No trauma was described. A bite mark was found on the left shoulder. Unfortunately no measuring tape has been used while taking the picture. b Chest radiograph obtained 2 weeks after the initial CT scan shows a series of posterior rib fractures on the left side with callus formation (arrow)

toma with clinical symptoms. No trauma was described. A bite mark was found on the left shoulder. Unfortunately no measuring tape has been used while taking the picture. b Chest radiograph obtained 2 weeks after the initial CT scan shows a series of posterior rib fractures on the left side with callus formation (arrow) Conclusion AHT is as prevalent in very young children as other potential lethal diseases, e.g., neonatal meningitis. It is the most common cause of neurotrauma in children younger than 1 year, and should therefore be considered in all children presenting with neurotrauma or unexplained neurological symptoms. The diagnosis should also be considered in children presenting with non-traumatic (aspecific) symptoms and signs such as increasing head circumference, children with failure-to-thrive, vomiting, crying excessively, poor drinking, developmental delay, as well as children who present with other forms of physical abuse and children with siblings who suffered severe physical abuse. About one-fifth of the children die and two-thirds of survivors are handicapped. The true extent of the damage cannot be assessed before school age, as neurological problems and low IQs can become apparent after a symptom-free interval. The clinician can only establish this diagnosis if he/she has knowledge on the signs and symptoms of AHT, risk factors, the differential diagnosis and which additional investigations to perform, as parents seldom will describe the true state of affairs spontaneously. AHT should be approached with as structured an approach as any other (potentially lethal) disease. History taking should be done extremely carefully and include contact with other health care providers, medical history of siblings, skull circumference growth curve and checking for CPS involvement. Physical examination should always be performed to look for additional signs of trauma. A differential diagnosis should be formulated and additional investigations should be performed to rule out or confirm alternative diagnoses. Birth trauma, coagulation disorders, metabolic disorders and accidental trauma are, besides AHT the most common causes of SDHs. All medical conditions should be ruled out before considering trauma to be the cause of the signs and symptoms. If trauma is the only option, it should be judged carefully whether accidental trauma is a possible explanation for the findings.

sorders and accidental trauma are, besides AHT the most common causes of SDHs. All medical conditions should be ruled out before considering trauma to be the cause of the signs and symptoms. If trauma is the only option, it should be judged carefully whether accidental trauma is a possible explanation for the findings. If no accidental trauma has been described that can cause the signs and symptoms, this option is excluded as well and AHT is the only remaining diagnosis. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.