A 9-month-old baby with subdural hematomas, retinal hemorrhages, and developmental delay

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.

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

Purpose

Glutaric aciduria type 1 (GA1) is a rare metabolic disorder of glutaryl-CoA-dehydrogenase enzyme deficiency. Children with GA1 are reported to be predisposed to subdural hematoma (SDH) development due to stretching of cortical veins secondary to cerebral atrophy and expansion of CSF spaces. Therefore, GA1 testing is part of the routine work-up in abusive head trauma (AHT). This systematic review addresses the coexistence of GA1 and SDH and the validity of GA1 in the differential diagnosis of AHT.

Methods

A systematic literature review, with language restriction, of papers published before 1 Jan 2015, was performed using Pubmed, PsychINFO, and Embase. Inclusion criteria were reported SDHs, hygromas or effusions in GA1 patients up to 18 years of age. Of 1599 publications, 20 publications were included for analysis.

Results

In total 20 cases, 14 boys and 6 girls, were included. In eight cases (40 %) a child abuse work-up was performed, which was negative in all cases. Clinical history revealed the presence of trauma in eight cases (40 %). In only one case neuroradiology revealed no abnormalities related to GA1 according to the authors, although on evaluation we could not exclude AHT.

Conclusion

From this systematic review we conclude that SDHs in 19/20 children with GA1 are accompanied by other brain abnormalities specific for GA1. One case with doubtful circumstances was the exception to this rule.

Cerebral haemodynamics in patients with glutaryl-coenzyme A dehydrogenase deficiency

In glutaric aciduria type 1, glutaryl-coenzyme A and its derivatives are produced from intracerebral lysine and entrapped at high concentrations within the brain, where they interfere with energy metabolism. Biochemical toxicity is thought to trigger stroke-like striatal degeneration in susceptible children under 2 years of age. Here, we explore vascular derangements that might also contribute to brain damage. We studied injured and non-injured Amish glutaric aciduria type 1 patients using magnetic resonance imaging (n = 26), transcranial Doppler ultrasound (n = 35) and perfusion computed tomography (n = 6). All glutaric aciduria type 1 patients had wide middle cerebral, internal carotid and basilar arteries. In non-injured patients, middle cerebral artery velocities were 18-26% below control values throughout late infancy and early childhood, whereas brain-injured children had an early velocity peak (18 months) and low values thereafter. Perfusion scans from six patients showed that tissue blood flow did not undergo a normal developmental surge. We observed four different perfusion patterns. (i) Three children (two non-injured) had low cerebral blood flow, prolonged mean transit time, elevated cerebral blood volume and high mean transit time/cerebral blood flow and cerebral blood volume/cerebral blood flow ratios. This pattern optimizes substrate extraction at any given flow rate but indicates low perfusion pressure and limited autoregulatory reserve. (ii) Ten hours after the onset of striatal necrosis in an 8-month-old infant, mean transit time and cerebral blood volume were low relative to cerebral blood flow, which varied markedly from region to region. This pattern indicates disturbed autoregulation, regional perfusion pressure gradients, or redistribution of flow from functional capillaries to non-exchanging vessels. (iii) In an infant with atrophic putaminal lesions, striatal flow was normal but mean transit time and cerebral blood volume were low, consistent with perfusion in excess of metabolic demand. (iv) Finally, a brain-injured adult with glutaric aciduria type 1 had regional perfusion values within the normal range, but the putamina, which normally have the highest regional perfusion, had cerebral blood flow values 24% below cortical grey matter. Although metabolic toxicity appears central to the pathophysiology of striatal necrosis, cerebrovascular changes probably also contribute to the process. These changes may be the primary cause of expanded cerebrospinal fluid volume in newborns, intracranial and retinal haemorrhages in infants and interstitial white matter oedema in children and adults. This pilot study suggests important new areas for clinical investigation.

Retinal hemorrhages associated with meningitis in a child with a congenital disorder of glycosylation

A 9-month old infant presented in a state of shock to a district hospital. She was subsequently referred to the regional tertiary hospital. On admission, bruises were noted on the vertex of the skull. Retinal hemorrhages were present on ophthalmological examination. CT scan of the brain showed poor grey-white matter differentiation with apparent frontoparietal fractures of the skull. Her case was subsequently referred to the relevant authorities as it was suspicious for nonaccident injury (NAI). Her condition deteriorated and she died the next day. Postmortem examination showed that the bruises on the vertex were caused by rapid widening of the sutures of the skull, caused by rising intracranial pressure. There was no skull fracture or evidence of trauma. Histological examination of the brain showed meningitis which had extended to the optic nerve sheath. Hemorrhages were noted in the retinas as well as the optic nerve sheath. An incidental congenital disorder of glycosylation (CDG) was diagnosed on brain histology and confirmed by metabolic tests. Retinal hemorrhages are known to occur in head injuries especially in association with NAI. In this case, suspicion of NAI was further augmented by the presence of apparent bruises on the head. The full postmortem examination showed no evidence of injuries and instead showed that the child was suffering from meningitis. Blood culture grew Group A Streptococcus pyogenes. The underlying mechanisms for such a presentation and the association with CDG are discussed.

Neuroimaging of nonaccidental head trauma: pitfalls and controversies

Although certain neuroimaging appearances are highly suggestive of abuse, radiological findings are often nonspecific. The objective of this review is to discuss pitfalls, controversies, and mimics occurring in neuroimaging of nonaccidental head trauma in order to allow the reader to establish an increased level of comfort in distinguishing between nonaccidental and accidental head trauma. Specific topics discussed include risk factors, general biomechanics and imaging strategies in nonaccidental head trauma, followed by the characteristics of skull fractures, normal prominent tentorium and falx versus subdural hematoma, birth trauma versus nonaccidental head trauma, hyperacute versus acute on chronic subdural hematomas, expanded subarachnoid space versus subdural hemorrhage, controversy regarding subdural hematomas associated with benign enlarged subarachnoid spaces, controversy regarding hypoxia as a cause of subdural hematoma and/or retinal hemorrhages without trauma, controversy regarding the significance of retinal hemorrhages related to nonaccidental head trauma, controversy regarding the significance of subdural hematomas in general, and pitfalls of glutaric aciduria type 1 and hemophagocytic lymphohistiocytosis mimicking nonaccidental head trauma.