A 10-month-old male is brought into ED by his parents with unexplained reduced level of consciousness and vomiting. He was noted to have a right sided parietal scalp haematoma.
He is very drowsy and only responding to painful stimuli.
The family were able to provide limited history, but there was no history of trauma.
A CT head scan is performed
Describe and interpret the CT scan
There is a large extradural mixed density acute haematoma overlying the right fronto-parietal temporal region.
It has significant mass effect causing, 8mm midline shift to the left with almost complete effacement of the right lateral ventricle and there is bulging of the frontal fontanelle.
There is a linear non-displaced fracture of the right parietal bone extended midway from the lambdoid to the squamous sutures.
There is a shallow subgaleal haematoma over the right parietal region.
The case demonstrates a large acute extradural haematoma in an infant with associated undisplaced fracture of the parietal bone.
Extradural bleeds are located between the outer layer of dura and endosteal layer of skull. Like in this case, they are usually associated with calvarial fractures.
The source of bleed is arterial in origin, from a middle meningeal artery as opposed to venous in subdural bleeds.
They typically demonstrate biconvex or lentiform shape and are limited by sutures as periosteum is attached at the sutures limiting spread of the bleed.
Hypodense areas within a bleed likely represent unclotted blood suggesting active bleeding.
In neonates and infants, an acute extradural bleed raises concern for non-accidental injury (NAI) if the history of trauma is not available like in this case.
Though more classic appearance of NAI in brain CTs is presence of subdural bleeds of different ages, or diffuse axonal injury or petechial haemorrhages. A large extradural bleed with fracture points towards a definite episode of trauma which could be concealed by carers.
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Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).
Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.