Introduction: Abusive head trauma (AHT) incidence is estimated to be about 20.2 – 55.4 per 100 000 live birth per year, with a high associated rate of mortality and severe disability. Subdural hematomas (SDH) are hallmark findings of AHT but their heterogenous radiological appearance complicates medico-legal dating. We report an infant with suspected AHT whose radiological appearance highlights the overlapping characteristics of the evolution of subdural collections and the imaging pitfalls associated.

Case report: A 2-month-old male presented with vomiting, hyperthermia and hypotonia at the emergency room after a reported low energy fall 2 days prior. Initial transfontanellar ultrasound was normal, but subsequent head CT and MRI revealed bilateral, heterogeneous and mixed-density SDH with suspected bridging vein thrombosis. Associated consolidated left clavicula fracture was discovered and authorities were notified. A follow up MRI at 1 month demonstrated enlargement of the SDH with apparition of neomembranes with subsequent neurosurgical treatment.

Discussion: This case underscore that a normal initial cranial ultrasound cannot rule out SDH in the context of AHT and illustrate how heterogeneous sub-dural collections in infants with chronic appearance on imaging can still reflet relatively recent abusive events, necessitating rapid appropriate imaging and careful medico-legal interpretation.Title: Acute to chronic evolution of subdural collections in an infant: a case report of suspected abusive head trauma