Subdural Hematomas and Glutaric Aciduria Type I

Abstract

To the Editor. I have read with great interest the recent paper of Morris and co-workers on the evaluation of infants with subdural hematoma and suspected child abuse.1 Under these circumstances one important differential diagnosis may be missed without the appropriate diagnostic tests. Glutaric aciduria type I (GA-I) secondary to deficiency of glutaryl CoA dehydrogenase is an inborn error of lysine, hydroxylysine, and tryptophan metabolism that may occur as frequently as 1:30,000 newborns.2 Infants and children with GA-I may present with subdural effusions and/or subdural hematoma, which may be accompanied by retinal hemorrhages.2–5 Macrocephaly is either present at birth or may develop during the first months of life. Early development in most children with GA-I is completely unremarkable before their initial encephalopathic episode occurs on average at 12 months of life.2The presence of GA-I warrants diagnostic consideration in cases with subdural hematoma with no additional physical findings suggestive of child abuse.6 The diagnostic workup should include urine analysis of organic acids, plasma carnitine/acylcarnitine analysis, measurement of enzyme activity in fibroblasts or leukocytes, and/or mutation analysis.In Reply. Dr Bodamer raises an important point in the evaluation of infants for possible child abuse. There have been instances in which infants with GA-I have had subdural collections mistaken for abusive injuries.In our series, GA-I was part of the differential especially in the oldest infant, who presented with a dystonic movement disorder. Urine organic acid analysis was normal in this patient. His subsequent lack of neurologic problems after social intervention made fibroblast or leukocyte culture or other testing unnecessary.None of the other patients in the series had clinical presentations suggesting GA-I nor did they have computed tomography or magnetic resonance imaging changes associated with that diagnosis apart from the subdural hematomas. All have been followed for a lengthy period since the initial diagnosis without subsequent neurologic episodes.Trauma is the primary cause of most infant subdural hematomas. Defining the nature of the trauma can be difficult for a single physician, but a specialized team investigation can help define the nature of the trauma, preventing recurrence and its attendant brain injury and even death. We thank Dr Bodamer for his reminder about a more rare cause of this condition.