Subdural hematomas: glutaric aciduria type 1 or abusive head trauma? A systematic review

Glutaric aciduria type 1: Insights into diagnosis and neurogenetic outcomes

Glutaric aciduria type 1 (GA1) is a rare metabolic disorder characterized by a deficiency in the enzyme glutaryl-CoA dehydrogenase. This study aims to present the clinical, biochemical, genetic, and neuroimaging findings of GA1 patients, emphasizing the importance of early detection and the potential benefits of incorporating GA1 into NBS programs. The demographic, clinical, and laboratory findings of GA1 patients were reviewed retrospectively. This study presents the clinical, biochemical, genetic, and neuroimaging findings of 15 patients (six males, nine females) from 13 families diagnosed with GA1. The median age at diagnosis was 20 months, and the median follow-up period was 72 months. Developmental delay was observed in 66.7% of patients, with 46.7% experiencing seizures and 33.3% suffering from encephalopathic crises. Biochemical analyses showed elevated levels of glutaric acid and 3-hydroxyglutaric acid in 93.3% and 80% of patients, respectively. Genetic testing identified the p.Arg402Trp variant in 53.3% of patients. Neurological evaluations revealed delays in motor and speech development, with 66.7% of patients never achieving the ability to walk. Cranial MRI indicated white matter changes in all patients and basal ganglia involvement in 93.3%. Despite significant biochemical improvements with treatment in glutaric acid levels and head circumference over time, neurological deficits remain unchanged. Growth parameters such as body weight showed significant decreases due to poor neurological outcomes.

CONCLUSION

The study underscores the importance of early diagnosis and intervention to mitigate severe neurological outcomes. Our findings highlight the need for incorporating GA1 into newborn screening programs to ensure timely diagnosis and treatment.

WHAT IS KNOWN

• Glutaric aciduria type 1 (GA1) is a rare metabolic disorder caused by a deficiency of glutaryl-CoA dehydrogenase. If untreated, it often leads to severe neurological complications. Early diagnosis and treatment are crucial for improving clinical outcomes in GA1 patients.

WHAT IS NEW

• This study presents comprehensive data from a cohort of 15 Glutaric aciduria type 1 (GA1) patients, detailing their biochemical, genetic, clinical, and neuroimaging findings. Drawing attention to the severe neurological findings in late-diagnosed patients underscores the critical importance of including GA1 in newborn screening programs to enhance early diagnosis and prevent severe outcomes.

Subdural Hemorrhage as an Early Presentation in a Case of Sotos Syndrome

Subdural hemorrhages (SDHs) in the pediatric population are associated with a high mortality and morbidity and may present in the context of abusive head trauma. Diagnostic investigations for such cases often include evaluation for rare genetic and metabolic disorders that can have associated SDH. Sotos syndrome is an overgrowth syndrome associated with macrocephaly and increased subarachnoid spaces and rarely with neurovascular complications. Here, we report two cases of Sotos syndrome, one with SDH during infancy who underwent repeated evaluation for suspected child abuse prior to the Sotos syndrome diagnosis and the other with enlarged extra-axial cerebrospinal fluid spaces, demonstrating a possible mechanism for SDH development in this setting. These cases suggest that some individuals with Sotos syndrome may be at elevated risk of developing SDH in infancy and that Sotos syndrome should be on the differential diagnosis during a medical genetics evaluation in cases of unexplained SDH, especially in the setting of macrocephaly.

Standardizing genetic and metabolic consults for non-accidental trauma at a large pediatric academic center

BACKGROUND

Evaluations of suspected non-accidental trauma (NAT) often include consultation with genetic and metabolic teams to assess patients for rare genetic conditions that can mimic or exacerbate child abuse. Diagnoses that may be questioned during court proceedings include osteogenesis imperfecta (OI) and glutaric aciduria type 1 (GA1). Currently there are no official society guidelines for the genetic or metabolic workup of suspected NAT.

OBJECTIVE

To standardize consult recommendations for suspected NAT through collaboration between the Genetics and Genomics Division and the Child Protection Team (CPT).

PARTICIPANTS AND SETTINGS

Children evaluated for suspected NAT at a single pediatric referral center.

METHODS

A year of inpatient consult requests for suspected NAT to the genetics division were reviewed. The most common indications for consult were fractures and subdural hematoma. Consult recommendations for similar indications varied between providers. A standard operating procedure (SOP) with specific recommendations for suspected NAT consults for fractures, intracranial hemorrhage, and other indications was created based on expert reviews and other relevant literature. A questionnaire assessing division practice patterns for these consults was distributed both pre (n = 17) and post-introduction of the SOP (n = 11).

RESULTS

Adherence to the SOP and impact on suspected NAT consult recommendations were assessed at 18 months after SOP introduction. Consult recommendations were in line with the SOP for 7/11 consults pre-intervention and 6/7 consults post-intervention. Providers were more likely to report feeling extremely or very confident they were using evidence-based medicine for NAT consults post-intervention.

Subdural Hygroma in an Infant with Marfan's Syndrome

Based on a patient encounter in which genetically confirmed Marfan's syndrome (MFS) underlay a spontaneously resolving subdural hygroma (SDHy) diagnosed in infancy, we review the literature of MFS clinically manifest in early life (early-onset MFS [EOMFS]) and of differential diagnoses of SDHy and subdural hemorrhage (SDHe) at this age. We found that rare instances of SDHy in the infant are associated with EOMFS. The most likely triggers are minimal trauma in daily life or spontaneous intracranial hypotension. The differential diagnosis of etiologies of SDHy include abusive and nonabusive head trauma, followed by perinatal events and infections. Incidental SDHy and benign enlargement of the subarachnoid spaces must further be kept in mind. SDHy exceptionally also may accompany orphan diseases. Thus, in the infant, EOMFS should be considered as a cause of SDHe and/or SDHy. Even in the absence of congestive heart failure, the combination of respiratory distress syndrome, muscular hypotonia, and joint hyperflexibility signals EOMFS. If EOMFS is suspected, monitoring is indicated for development of SDHe and SDHy with or without macrocephaly. Close follow-up is mandatory.

Subdural hematoma in glutaric aciduria type 1: High excreters are prone to incidental SDH despite newborn screening

Subdural hematoma (SDH) was initially reported in 20% to 30% of patients with glutaric aciduria type 1 (GA1). A recent retrospective study found SDH in 4% of patients, but not in patients identified by newborn screening (NBS). 168 MRIs of 69 patients with GA1 (age at MRI 9 days - 73.8 years, median 3.2 years) were systematically reviewed for presence of SDH, additional MR and clinical findings in order to investigate the frequency of SDH and potential risk factors. SDH was observed in eight high-excreting patients imaged between 5.8 and 24.4 months, namely space-occupying SDH in two patients after minor accidental trauma and SDH as an incidental finding in six patients without trauma. In patients without trauma imaged at 3 to 30 months (n = 36, 25 NBS, 27/9 high/low excreters), incidence of SDH was 16.7% (16% in NBS). SDH was more common after acute (33.3%) than insidious onset of dystonia (14.3%) or in asymptomatic patients (5.9%). It was only seen in patients with wide frontoparietal CSF spaces and frontotemporal hypoplasia. High excreters were over-represented among patients with SDH (6/27 vs 0/9 low excreters), acute onset (10/12), and wide frontoparietal CSF spaces (16/19). Incidental SDH occurs despite NBS and early treatment in approximately one in six patients with GA1 imaged during late infancy and early childhood. Greater risk of high excreters is morphologically associated with more frequent enlargement of external CSF spaces including frontotemporal hypoplasia, and may be furthered aggravated by more pronounced alterations of cerebral blood volume and venous pressure.

D2-Hydroxyglutaric Aciduria Type II with Subdural Hemorrhage Identified in a 3-Month-Old Infant: A Case Report

Subdural hemorrhage in association with D2-hydroxyglutaric aciduria (D2-HGA) Type II has only been described once in the medical literature in a 15-month-old child (1). Our case report describes a much younger 3-month-old infant previously diagnosed with D2-HGA Type II, who presented clinically with seizures and identified to have bilateral subdural hematomas concerning for possible physical abuse. This case report discusses the genetic diagnosis of D2-HGA and interpretation of subdural hemorrhage in context of evaluating possible physical abuse concerns. When an underlying medical condition is known to be present and a child presents with findings that may be concerning for physical abuse, it is critical to consider the possibility that the underlying medical condition may contribute to or may be the cause of the findings.

Bilateral arachnoid cyst-associated subdural fluid collections in an infant following TBI

INTRODUCTION

arachnoid cyst-associated subdural fluid collections have been documented in children and adults following traumatic brain injury (TBI). However, this phenomenon has not been previously demonstrated in infants less than 12 months of age. We present a case of an infant with bilateral arachnoid cyst-associated subdural fluid collections identified after TBI.

CASE PRESENTATION

a 9-month-old female infant with profound macrocephaly presented to medical care with altered mental status following a witnessed fall down steps while unsecured in a stroller. Neuroimaging revealed bilateral subdural fluid collections, in addition to a hyperdense subdural hematoma, that raised concern for abusive head trauma (AHT) among the pediatric inpatient team and the hospital's Suspected Child Abuse and Neglect (SCAN) Team was consulted. After excluding occult abusive injuries as well as testing for underlying medical conditions, the infant's bilateral subdural fluid collections were attributed to rupture of a pre-existing left middle cranial fossa arachnoid cyst with evidence of prior macrocephaly.

CONCLUSION

In infants and toddlers, the identification of subdural fluid collections on neuroimaging warrants inclusion of AHT in the differential diagnosis. However, in infants with a history of congenital macrocephaly, and an otherwise negative AHT workup, an accidental mechanism for the formation of subdural collections should be considered, especially when co-occurring with an arachnoid cyst.

Abusive head trauma: neuroimaging mimics and diagnostic complexities

Traumatic brain injury is responsible for approximately half of all childhood deaths from infancy to puberty, the majority of which are attributable to abusive head trauma (AHT). Due to the broad way patients present and the lack of a clear mechanism of injury in some cases, neuroimaging plays an integral role in the diagnostic pathway of these children. However, this nonspecific nature also presages the existence of numerous conditions that mimic both the clinical and neuroimaging findings seen in AHT. This propensity for misdiagnosis is compounded by the lack of pathognomonic patterns and clear diagnostic criteria. The repercussions of this are severe and have a profound stigmatic effect. The authors present an exhaustive review of the literature complemented by illustrative cases from their institutions with the aim of providing a framework with which to approach the neuroimaging and diagnosis of AHT.

Impact of interventional and non-interventional variables on anthropometric long-term development in glutaric aciduria type 1: A national prospective multi-centre study

Glutaric aciduria type 1 (GA1) is a rare neurometabolic disorder, caused by inherited deficiency of glutaryl-CoA dehydrogenase, mostly affecting the brain. Early identification by newborn screening (NBS) significantly improves neurologic outcome. It has remained unclear whether recommended therapy, particular low lysine diet, is safe or negatively affects anthropometric long-term outcome. This national prospective, observational, multi-centre study included 79 patients identified by NBS and investigated effects of interventional and non-interventional parameters on body weight, body length, body mass index (BMI) and head circumference as well as neurological parameters. Adherence to recommended maintenance and emergency treatment (ET) had a positive impact on neurologic outcome and allowed normal anthropometric development until adulthood. In contrast, non-adherence to ET, resulting in increased risk of dystonia, had a negative impact on body weight (mean SDS -1.07; P = .023) and body length (mean SDS -1.34; P = -.016). Consistently, longitudinal analysis showed a negative influence of severe dystonia on weight and length development over time (P < .001). Macrocephaly was more often found in female (mean SDS 0.56) than in male patients (mean SDS -0.20; P = .049), and also in individuals with high excreter phenotype (mean SDS 0.44) compared to low excreter patients (mean SDS -0.68; P = .016). In GA1, recommended long-term treatment is effective and allows for normal anthropometric long-term development up to adolescence, with gender- and excreter type-specific variations. Delayed ET and severe movement disorder result in poor anthropometric outcome.

Genetic causes of fractures and subdural hematomas: fact versus fiction

Genetic disorders are in the differential diagnosis when young children present with unexplained fractures or intracranial hemorrhage. For medical and legal reasons, it is imperative to make the correct diagnosis and provide clear, evidence-based explanations of how alternative diagnoses were ruled out. A genetics consultation in cases of suspected child physical abuse should synthesize the history of present illness, medical history, family history, physical examination, and radiologic and laboratory findings in consultation with other specialists. The medical geneticist highlights how these disorders truly present. When the natural history of a genetic disorder is understood, it becomes clear that genetic disorders are not mysterious or difficult to diagnose. As highlighted in this case-based review, mainstream medical practice allows for differentiation among the intracranial and skeletal manifestations of osteogenesis imperfecta, Menkes disease, glutaric acidemia type 1 and child physical abuse. This review also highlights how a genetic disorder, Ehlers-Danlos syndrome, can be misused in a courtroom. Finally, this review summarizes when genetic testing is appropriate in cases of suspected child physical abuse.

Abusive head trauma: experience improves diagnosis

PURPOSE

The diagnosis of abusive head trauma (AHT) is complex and neuroimaging plays a crucial role. Our goal was to determine whether non-neuroradiologists with standard neuroradiology knowledge perform as well as neuroradiologists with experience in pediatric neuroimaging in interpreting MRI in cases of presumptive AHT (pAHT).

METHODS

Twenty children were retrospectively evaluated. Patients had been diagnosed with pAHT (6 patients), non-abusive head trauma-NAHT (5 patients), metabolic diseases (3 patients), and benign enlargement of the subarachnoid spaces (BESS) (6 patients). The MRI was assessed blindly, i.e., no clinical history was given to the 3 non-neuroradiologists and 3 neuroradiologists from 2 different institutions.

RESULTS

Blindly, neuroradiologists demonstrated higher levels of sensitivity and positive predictive value in the diagnosis of pAHT (89%) than non-neuroradiologists (50%). Neuroradiologists chose correctly pAHT as the most probable diagnosis 16 out of 18 times; in contrast, non-neuroradiologists only chose 9 out of 18 times. In our series, the foremost important misdiagnosis for pAHT was NAHT (neuroradiologists twice and non-neuroradiologists 5 times). Only victims of motor vehicle accidents were blindly misdiagnosed as pAHT. No usual household NAHT was not misdiagnosed as pAHT. Neuroradiologists correctly ruled out pAHT in all cases of metabolic diseases and BESS.

CONCLUSION

MRI in cases of suspected AHT should be evaluated by neuroradiologists with experience in pediatric neuroimaging. Neuroradiologists looked beyond the subdural hemorrhage (SDH) and were more precise in the assessment of pAHT and its differential diagnosis than non-neuroradiologists were. It seems that non-neuroradiologists mainly assess whether or not a pAHT is present depending on the presence or absence of SDH.

Bilateral subdural hematomas and retinal hemorrhages mimicking nonaccidental trauma in a patient with D-2-hydroxyglutaric aciduria

INTRODUCTION

Nonaccidental trauma (NAT) is considered when pediatric patients present with intracranial injuries and a negative history of an accidental injury or concomitant medical diagnosis. The evaluation of NAT should include the consideration of possible medical causes including coagulation, hematologic, metabolic and other genetic disorders, as well as witnessed and unwitnessed accidental injuries.

CASE PRESENTATION

We present a 7-month-old male with spells and incidental findings of bilateral subdural hematomas, retinal hemorrhages, and secondary macrocephaly, leading to investigation for NAT. Biochemical analysis showed excretion of a large amount of D-2-hydroxyglutaric in urine consistent with a biochemical diagnosis of D-2-hydroxyglutaric aciduria, a rare neurometabolic disorder characterized by developmental delay, epilepsy, hypotonia, and psychomotor retardation. None of these symptoms were present in our patient at the time of diagnosis. Molecular genetic testing revealed a pathogenic splice site variant (c.685-2A>G) and a variant of uncertain significance (c.1256G>T) with evidence of pathogenicity in the D2HGDH gene, consistent with a molecular diagnosis of D-2-hydroxyglutaric aciduria type I (OMIM #600721).

CONCLUSION

Since several metabolic disorders, including D-2-hydroxyglutaric aciduria type I, can present solely with symptoms suggestive of NAT (subdural and retinal hemorrhages), an early metabolic evaluation by urine organic acid analysis should be included in clinical protocols evaluating NAT. A methodical and nonjudgmental approach coordinated between pediatricians and metabolic specialists is also necessary to ensure that rare genetic conditions are not overlooked to prevent devastating social, legal, and financial consequences of suspected child abuse.

Genetic consultations in cases of unexplained fractures and haemorrhage: an evidence-based approach

PURPOSE OF REVIEW

When infants and young children present with suspected physical abuse, it is critical to follow standard guidelines and rule out alternative causes of fracture and haemorrhage. A multidisciplinary team involved in the initial evaluation typically includes paediatrics, radiology, child protective services and/or law enforcement, and in complex cases, haematology, neurology, and genetics. A comprehensive genetics consultation includes review of the history of present illness, birth and past medical history, review of growth curves, family history, physical examination, radiological findings, and when indicated, biochemical and/ or genetic testing.

RECENT FINDINGS

A number of reports have mischaracterized several genetic disorders as child abuse mimics. There is a difference between a differential diagnosis, which includes every condition that can cause a fracture and/or subdural haemorrhage, and a mimic, so called because it can be difficult to differentiate from child abuse. In this review, we discuss the differential diagnosis for infantile fractures and subdural bleeds, highlight cardinal signs and symptoms of genetic disorders, and demonstrate that these genetic disorders can be readily differentiated and diagnosed using a stepwise approach. Genetic disorders rarely, if ever, are truly mimics of child physical abuse.

SUMMARY

In cases of suspected child physical abuse, multidisciplinary evaluations by paediatric specialists, keen clinical judgment, complete physical examinations, and judicious testing provides an evidence-based, time tested approach to excluding genetic disorders and diagnosing suspected child physical abuse.

Diagnostic Approach to Macrocephaly in Children

Macrocephaly affects up to 5% of the pediatric population and is defined as an abnormally large head with an occipitofrontal circumference (OFC) >2 standard deviations (SD) above the mean for a given age and sex. Taking into account that about 2-3% of the healthy population has an OFC between 2 and 3 SD, macrocephaly is considered as "clinically relevant" when OFC is above 3 SD. This implies the urgent need for a diagnostic workflow to use in the clinical setting to dissect the several causes of increased OFC, from the benign form of familial macrocephaly and the Benign enlargement of subarachnoid spaces (BESS) to many pathological conditions, including genetic disorders. Moreover, macrocephaly should be differentiated by megalencephaly (MEG), which refers exclusively to brain overgrowth, exceeding twice the SD (3SD-"clinically relevant" megalencephaly). While macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, megalencephaly is most likely due to a genetic cause. Apart from the head size evaluation, a detailed family and personal history, neuroimaging, and a careful clinical evaluation are crucial to reach the correct diagnosis. In this review, we seek to underline the clinical aspects of macrocephaly and megalencephaly, emphasizing the main differential diagnosis with a major focus on common genetic disorders. We thus provide a clinico-radiological algorithm to guide pediatricians in the assessment of children with macrocephaly.

Chemistry and Effects of Brainstem Acting Drugs

BACKGROUND

Brain is the most sensitive organ, whereas brainstem is the most important part of Central Nervous System (CNS). It connects the brain and the spinal cord. However, a myriad of drugs and chemicals affects CNS with severe resultant effects on the brainstem.

METHODS

In view of this, a number of literature were assessed for information on the most sensitive part of brain, drugs and chemicals that act on the brainstem and clinical benefit and risk assessment of such drugs and chemicals.

RESULTS

Findings have shown that brainstem regulates heartbeat, respiration and because it connects the brain and spinal cord, all the drugs that act on the spinal cord may overall affect the systems controlled by the spinal cord and brain. The message is sent and received by temporal lobe, occipital lobe, frontal lobe, parietal lobe and cerebellum.

CONCLUSION

Hence, the chemical functional groups of the brainstem and drugs acting on brainstem are complementary, and may produce either stimulation or depression of CNS.

The neuroimaging mimics of abusive head trauma

Abusive head trauma (AHT) is a significant cause of morbidity and mortality in the paediatric population, typically in children under the age of two years. Neuroimaging plays a key role in the diagnostic work up of these patients as information regarding the mechanism of injury is often lacking and the findings on examination can be nonspecific. A number of conditions, both traumatic and atraumatic can mimic AHT based on neuroimaging features alone. The repercussions associated with a diagnosis or misdiagnosis of AHT can be severe and radiologists therefore need to be aware of and familiar with the imaging differentials of AHT. In this paper we review the imaging findings of the radiological mimics of AHT and focus on features that can help differentiate these entities from AHT.

Ocular and Intracranial MR Imaging Findings in Abusive Head Trauma

Abusive head trauma (AHT) is a form of inflicted head injury. AHT is more frequent in 2-year-old or younger children. It is an important cause of neurological impairment and the major cause of death from head trauma in this age group. Brain magnetic resonance imaging allows the depiction of retinal hemorrhages, injured bridging veins, and identifying and localizing extra- and intra-axial bleeds, contusions, lacerations, and strokes. The diagnosis of AHT is a multidisciplinary team effort which includes a careful evaluation of social, clinical, laboratory, and radiological findings. Notwithstanding, the introduction in the current clinical practice of high-resolution techniques is adding forensic evidence to the recognition of AHT.

Organic acidurias in adults: late complications and management

Organic acidurias (synonym, organic acid disorders, OADs) are a heterogenous group of inherited metabolic diseases delineated with the implementation of gas chromatography/mass spectrometry in metabolic laboratories starting in the 1960s and 1970s. Biochemically, OADs are characterized by accumulation of mono-, di- and/or tricarboxylic acids ("organic acids") and corresponding coenzyme A, carnitine and/or glycine esters, some of which are considered toxic at high concentrations. Clinically, disease onset is variable, however, affected individuals may already present during the newborn period with life-threatening acute metabolic crises and acute multi-organ failure. Tandem mass spectrometry-based newborn screening programmes, in particular for isovaleric aciduria and glutaric aciduria type 1, have significantly reduced diagnostic delay. Dietary treatment with low protein intake or reduced intake of the precursor amino acid(s), carnitine supplementation, cofactor treatment (in responsive patients) and nonadsorbable antibiotics is commonly used for maintenance treatment. Emergency treatment options with high carbohydrate/glucose intake, pharmacological and extracorporeal detoxification of accumulating toxic metabolites for intensified therapy during threatening episodes exist. Diagnostic and therapeutic measures have improved survival and overall outcome in individuals with OADs. However, it has become increasingly evident that the manifestation of late disease complications cannot be reliably predicted and prevented. Conventional metabolic treatment often fails to prevent irreversible organ dysfunction with increasing age, even if patients are considered to be "metabolically stable". This has challenged our understanding of OADs and has elicited the discussion on optimized therapy, including (early) organ transplantation, and long-term care.

Macrocephaly: Solving the Diagnostic Dilemma

Macrocephaly is a relatively common clinical condition affecting up to 5% of the pediatric population. It is defined as an abnormally large head with an occipitofrontal circumference greater than 2 standard deviations above the mean for a given age and sex. Megalencephaly refers exclusively to brain overgrowth exceeding twice the standard deviation. Macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, whereas megalencephaly is more often syndromic. Megalencephaly can be divided into 2 subtypes: metabolic and developmental, caused by genetic defects in cellular metabolism and alterations in signaling pathways, respectively. Neuroimaging plays an important role in the evaluation of macrocephaly, especially in the metabolic subtype which may not be overtly apparent clinically. This article outlines the diverse etiologies of macrocephaly, delineates their clinical and radiographic features, and suggests a clinicoradiological algorithm for evaluation.

Inborn Errors of Metabolism in the Emergency Department (Undiagnosed and Management of the Known)

An inborn error of metabolism should be considered in any neonate who presents to the emergency department in extremis and in any young child who presents with altered mental status and vomiting. In children with unknown diagnoses, it is crucial to draw the appropriate laboratory studies before the institution of therapy, although treatment needs rapid institution to mitigate neurologic damage and avoid worsening metabolic crisis. Although there are hundreds of individual genetic disorders, they are roughly placed into groups that present similarly. This article reviews the approach to the patient with unknown metabolic diagnosis and up-to-date management pearls for children with known disorders.

Inborn Errors of Metabolism with Acidosis: Organic Acidemias and Defects of Pyruvate and Ketone Body Metabolism

When a child presents with high-anion gap metabolic acidosis, the pediatrician can proceed with confidence by recalling some basic principles. Defects of organic acid, pyruvate, and ketone body metabolism that present with acute acidosis are reviewed. Flowcharts for identifying the underlying cause and initiating life-saving therapy are provided. By evaluating electrolytes, blood sugar, lactate, ammonia, and urine ketones, the provider can determine the likelihood of an inborn error of metabolism. Freezing serum, plasma, and urine samples during the acute presentation for definitive diagnostic testing at the provider's convenience aids in the differential diagnosis.

The Anesthesiologist's Role in Treating Abusive Head Trauma

Abusive head trauma (AHT) is the most common cause of severe traumatic brain injury (TBI) in infants and the leading cause of child abuse-related deaths. For reasons that remain unclear, mortality rates after moderate AHT rival those of severe nonintentional TBI. The vulnerability of the developing brain to injury may be partially responsible for the poor outcomes observed after AHT. AHT is mechanistically more complex than nonintentional TBI. The acute-on-chronic nature of the trauma along with synergistic injury mechanisms that include rapid rotation of the brain, diffuse axonal injury, blunt force trauma, and hypoxia-ischemia make AHT challenging to treat. The anesthesiologist must understand the complex injury mechanisms inherent to AHT, as well as the pediatric TBI treatment guidelines, to decrease the risk of persistent neurologic disability and death. In this review, we discuss the epidemiology of AHT, differences between AHT and nonintentional TBI, the severe pediatric TBI treatment guidelines in the context of AHT, anesthetic considerations, and ethical and legal reporting requirements.

Proposed recommendations for diagnosing and managing individuals with glutaric aciduria type I: second revision

Glutaric aciduria type I (GA-I; synonym, glutaric acidemia type I) is a rare inherited metabolic disease caused by deficiency of glutaryl-CoA dehydrogenase located in the catabolic pathways of L-lysine, L-hydroxylysine, and L-tryptophan. The enzymatic defect results in elevated concentrations of glutaric acid, 3-hydroxyglutaric acid, glutaconic acid, and glutaryl carnitine in body tissues, which can be reliably detected by gas chromatography/mass spectrometry (organic acids) and tandem mass spectrometry (acylcarnitines). Most untreated individuals with GA-I experience acute encephalopathic crises during the first 6 years of life that are triggered by infectious diseases, febrile reaction to vaccinations, and surgery. These crises result in striatal injury and consequent dystonic movement disorder; thus, significant mortality and morbidity results. In some patients, neurologic disease may also develop without clinically apparent crises at any age. Neonatal screening for GA-I us being used in a growing number of countries worldwide and is cost effective. Metabolic treatment, consisting of low lysine diet, carnitine supplementation, and intensified emergency treatment during catabolism, is effective treatment and improves neurologic outcome in those individuals diagnosed early; treatment after symptom onset, however, is less effective. Dietary treatment is relaxed after age 6 years and should be supervised by specialized metabolic centers. The major aim of this second revision of proposed recommendations is to re-evaluate the previous recommendations (Kölker et al. J Inherit Metab Dis 30:5-22, 2007b; J Inherit Metab Dis 34:677-694, 2011) and add new research findings, relevant clinical aspects, and the perspective of affected individuals.

Severe Acute Subdural Hemorrhages in a Patient with Glutaric Acidemia Type 1 under Recommended Treatment

Glutaric acidemia type 1 is a rare autosomal recessive disease caused by a deficiency of glutaryl-CoA dehydrogenase. Previous studies have reported subdural hemorrhage in untreated patients with glutaric acidemia type 1. However, there is only one report of severe acute subdural hemorrhage after minor head trauma in a patient with glutaric acidemia type 1 under guideline-recommended treatment. We report a second case of life-threatening severe acute subdural hemorrhage after a minor head trauma in a patient with glutaric acidemia type 1. This patient was previously diagnosed by newborn screening, and treatment began at 25 days of age. Early diagnosis and guideline-recommended treatment produce better outcomes for patients with glutaric acidemia type 1, although the risk of subdural hemorrhage remains.

Clinical and laboratory analysis of late-onset glutaric aciduria type I (GA-I) in Uighur: A report of two cases

The aim of the present study was to investigate the clinical, biochemical and genetic mutation characteristics of two cases of late-onset glutaric aciduria type I (GA-I) in Uighur. The clinical data and glutaryl-CoA dehydrogenase (GCDH) genetic test results of two cases of late-onset GA-I in Uighur were collected and analyzed, and reviewed with relevant literature. One patient with late-onset GA-I primarily exhibited clinical intermittent headache, while the other patient was asymptomatic. The urinary organic acid analysis detected a large number of glutaric acid and 3-hydroxy glutaric acid, 3-hydroxy-propionic acid. One patient exhibited white matter degeneration in cranial magnetic resonance imaging (MRI) and the other patient showed no abnormality. The two patients both exhibited c. 1204C >T, p.R402W, heterozygous mutation, and c. 532G >A, p.G178R, heterozygous mutation. Besides central nervous system infectious diseases, patients with clinical headache, cranial MRI-suggested bilateral temporal lobe arachnoid cyst and abnormal signals in the basal ganglia should be highly suspected as late-onset GA-I. Early diagnosis and correct treatment are key to improve its prognosis.

[Complementary exams in child abuse: A French national study in 2015]

INTRODUCTION

Even if there are HAS (French National Health Authority) guidelines on shaken baby syndrome, many other child abuse situations are not included in these recommendations. The aim of this study was to invent the complementary exams in cases of child abuse in France and compare the practice to existing guidelines.

MATERIAL AND METHODS

This was a multicenter study by email to 128 French hospitals (35 university hospitals and 93 general hospitals) that receives children in emergency and hospitalization settings. Three child abuse clinical situations were included in a clinical case multiple-choice format concerning the further explorations. We described the main results and evaluated their adherence to the HAS protocol for case 1.

RESULTS

Of 128 hospitals surveyed, 104 responded, for an 81 % response rate, which corresponded to 274 doctors. Analysis of the results showed great heterogeneity in practices. The majority of physicians (99 %) performed systematic explorations in the situation of physical abuse, while only 27 % undertook such exams in situations of serious neglect. The situation of sexual abuse was the most consensual in terms of diagnostic tests for the detection of sexually transmitted diseases, but other types of associated abuse were not sought. In the first case, the HAS guidelines were respected in less than half of the cases for all complementary exams except the eye fundus exam. Abdominal imaging was insufficiently performed (40 % of cases). Examinations that were not indicated were still prescribed. Moreover, siblings under 2 years of age were examined in only one-third of cases (n=88/274; 32 %). Practices were not influenced by the age of the child.

CONCLUSION

This study illustrates the heterogeneity in the use of complementary exams in cases of child abuse in France. Common protocols throughout the country would be useful, standardizing the most relevant exams for potential medical-legal issues, and facilitating exchanges concerning practices between different centers.

Occurrence of subdural hematomas in Dutch glutaric aciduria type 1 patients

Patients with glutaric aciduria type 1 (GA1), a rare inherited metabolic disorder, have an increased risk for subdural hematomas (SDHs). GA1 is therefore generally included in the differential diagnosis of children presenting with SDHs. This retrospective cohort study reviews all 25 registered, in the Dutch Diagnosis Registration for Metabolic Disorders, GA1 patients in the Netherlands. This was done between May 2014 and November 2014 to determine the lifetime incidence of SDHs in this population. Seventeen patients were diagnosed either due to clinical symptoms or because of family members with GA1. One out of these 17 had a SDH. This patient showed widened Sylvian fissures on MRI, characteristic for GA1. Eight patients were diagnosed by newborn screening. Three of them had neuroimaging results, and none of them had SDHs. This study shows an overall lower incidence (4.0 %) of SDHs in patients with GA1 than reported in the literature (20-30 %).

CONCLUSION

This finding, in combination with the fact that SDHs in GA1 appear to occur only in the presence of characteristic brain abnormalities on imaging, we recommend that GA1 should not routinely be a part of the differential diagnosis of children with unexplained SDHs in the absence of imaging characteristics suggestive of GA1.

WHAT IS KNOWN

• Glutaric aciduria type 1 is a rare metabolic disorder predisposing children to subdural hematoma development due to brain abnormalities. • Because of these subdural hematomas, glutaric aciduria type 1 testing is part of abusive head trauma work-up. What is new: • The overall subdural hematoma incidence in glutaric aciduria type 1 patients is much lower than previously reported and only occurs in case of predisposing brain abnormalities.