Holohemispheric Subdural Hematoma: Infantile Acute Subdural Hematoma Localized in the Dural Border Cell Layer

Background: Acute subdural hematoma (ASDH) in an infant without external signs of head trauma is sometimes thought to be symptomatic of shaken baby syndrome (SBS) or abusive head trauma (AHT) in the United States or of infantile acute subdural hematoma (IASDH) due to minor head trauma in Japan.The present case report aimed to demonstrate that IASDH can occur spontaneously if the dural border cell layer is disrupted in an infant with cranio-cerebral disproportion (CCD).Case description: A 3-month-old, female patient developed vomiting while being fed with her mother's breast milk.On the next morning, she vomited again and during the night of the same day suddenly began crying after displaying generalized convulsions.The patient was taken to an emergency room, where head computed tomography found an ASDH on the right side.An ophthalmological examination revealed right-sided retinal hemorrhages.Magnetic resonance imaging on hospital day 2 revealed a thin, film-like, high-intensity ASDH surrounding the entire, cerebral convexity on the right side.In addition, benign enlargement of the subarachnoid space (BESS) and sylvian fissure (LSF) was noted.On hospital day 2, the vomiting and seizures subsided, and the remainder of her clinical course was uneventful. Conclusion:The present case is invaluable because it demonstrates that IASDH can occur in the absence of an external impact to the head.The diagnostic criteria for SBS/AHT, particularly in terms of their application to very young infants, need to be reviewed, considering that the presence of CCD, including BESS and LSF, may cause IASDH even without trauma.Particularly relevant here is the thin, film-like, holohemispheric appearance on neuroimaging studies characterizing IASDH localized in the disrupted Dural border cell layer.The present study proposes the term, holohemispheric subdual hematoma, to describe this phenomenon.