Overrepresentation of Males in Traumatic Brain Injury of Infancy and in Infants With Macrocephaly

Abstract

Shaken baby syndrome (SBS) has been thought to be caused by violent shaking of an infant and is characterized by the triad of findings: subdural hematoma (SDH), retinal hemorrhages, and neurologic abnormalities. The triad is not specific for SBS and can be seen in accidental trauma and in certain medical conditions. Recent observations, however, question whether SBS exists. Herein, we review the gender differences in 3 groups of infants with traumatic brain injury: (1) neonates with SDH from birth trauma, (2) infants with SDH from accidental trauma, and (3) infants with SDH from SBS. Gender differences are also presented in a fourth group of infants with macrocephaly related to increased extra-axial fluid spaces (IEAFS). Compared with the expected male frequency of 51.4% in newborns, there was a statistically significant overrepresentation of males in each of the 4 groups-65.3%, 62.2%, 62.6%, and 68.8%, respectively. We believe that the most likely explanation for these findings relates to the larger head size of the male compared with the female which has several relevant consequences. First, the larger head circumference of a male newborn compared with a female newborn may increase the likelihood that a male newborn will incur a small SDH from the minor trauma of the birthing process that can later rebleed and present with a symptomatic SDH that could be misdiagnosed as SBS and child abuse. Second, a short fall would have a greater likelihood of causing a SDH in a male infant than a female infant who could subsequently become symptomatic from hours to weeks later and could thus present as an unexplained SDH. Third, infants with macrocephaly related to IEAFS may be at increased risk for developing a SDH from the larger head size and greater tautness of the bridging vessels in the extra-axial fluid spaces. We believe that many infants who have been diagnosed with SBS have been given incorrect diagnoses of child abuse. Rather, their SDH may occur as a result of a small SDH from the birthing process that enlarges during early infancy, a short fall, or from macrocephaly with IEAFS.

Is “Shaken Baby Syndrome” The Malignant Peak of A “Benign Hydrocephalus of Infancy” Iceberg?

“…This would allow whole blood to escape, producing the haemorrhages of "Shaken Baby Syndrome". Furthermore, if SBS conviction cases are actually simply External Hydrocephalus at higher pressure, SBS would also be expected to show a similar 2:1 male dominance, which Miller and Miller [1] did find.…”

“…Miller and Miller [1] studied Traumatic Brain Injury of Infancy, (TBII). Relevant scientific articles published between 1966 and 2005, were found by searching MEDLINE with the keywords "Shaken Baby Syndrome", "Retinal Hemorrhage", and "Subdural Hematoma".…”

“…When Miller and Miller [1] searched MEDLINE using the Keywords "Shaken Baby Syndrome", "Retinal Hemorrhage", and "Subdural Hematoma" to select SBS convictions, they found male infants outnumbered female infants by about 2:1. They then searched MEDLINE selecting for External Hydrocephalus.…”

Application of Hill’s criteria of causation to shaken baby syndrome: Further evidence that questions the existence of shaken baby syndrome

“…The reflexive diagnosis of child abuse without consideration of these alternative diagnoses can lead to misdiagnosis and devastating and irreparable consequences for the family [36] . Relatively common medical mimics of the triad include [37,38] : Six infants with the above mimics were recently reported in which child abuse was initially diagnosed. In all cases the parents denied wrongdoing, and each infant was returned to the parents after legal proceedings.…”

Overrepresentation of New Zealand’s Maori in Presumed Shaken Baby Syndrome – Nature or Nurture?

“…[1] Lines [2] has reported on the larger head size of the Maori in a high school age group (European 55.2 cm, Maori 55.6) and Anderson [3] in 0-2 year old non-breast fed children (European mean head circumference 43.3 percentile, Maori 48.6). Anderson did show a higher mean in a smaller number of breast fed European children but the combined figures support the larger size in the Maori (European 47.4, Maori 48.9).…”