Nonaccidental head injury is the most common cause of subdural bleeding in infants <1 year of age.
OBJECTIVE
Subdural bleeding (SDB) in infants is considered an essential symptom of nonaccidental head injury (NAHI). Recently, this view has been challenged by the "unified hypothesis," which claims that SDB in infants is related to hypoxia and brain swelling rather than to traumatic shearing of bridging veins. We analyzed a large series of infants' autopsies for the presence and causes of SDB, which should be a common event according to the unified hypothesis.


METHODS
Autopsy, clinical, and legal information for infants <1 year of age from a single institution over 50 years were analyzed regarding cause of death, presence, morphology, and cause of SDB, and brain weight.


RESULTS
From a total of 16 661 autopsies during the study period, 715 (4.3%) involved infants <1 year of age. Fifty (7.0%) of those had SDB. NAHI was identified in 17 patients. The most common cause of SDB was trauma (15 cases [30.0%]), with NAHI accounting for 14 cases. SDB was present in 82.4% of patients with NAHI but only 5.2% of infants with other causes of death. Four patients (8.0%) had unexplained SDB with no discernible cause of bleeding. Statistical analysis did not reveal any correlation between the presence of SDB and brain weight.


CONCLUSIONS
In the study population, unexplained SDB in infants was an extreme rarity. Moreover, a correlation between brain swelling and the presence of SDB could not be drawn. Our data argue strongly against the unified hypothesis and strengthen the association between SDB and NAHI in infancy.
Matschke
Jakob
J
Forensic Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. matschke@uke.de
Voss
Janina
J
Obi
Nadia
N
Görndt
Jennifer
J
Sperhake
Jan-Peter
JP
Püschel
Klaus
K
Glatzel
Markus
M
D000367:Age Factors; D001921:Brain / Q000473:pathology; D001929:Brain Edema / Q000473:pathology; D002423:Cause of Death; D002550:Cerebral Veins / Q000473:pathology; D002649:Child Abuse / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D003937:Diagnosis, Differential; D005260:Female; D005858:Germany; D016489:Head Injuries, Closed / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D046648:Hematoma, Subdural, Intracranial / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D006801:Humans; D002534:Hypoxia, Brain / Q000473:pathology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009929:Organ Size / Q000502:physiology; D012189:Retrospective Studies