Intermediary injury

Case contributed by Dr Henry Knipe


High-energy trauma. GCS 3.

Patient Data

Age: 25 years
Gender: Male

Small volume of traumatic subarachnoid at the vertex and in the prepontine cistern. Small volume of intraventricular hemorrhage. Sulcal effacement but with preserved grey white matter differentiation. Hyperdensity at the left basal ganglia is suspicious for a petechial hemorrhage. 


24 hours later

At the site of a petechial hemorrhage in the left basal ganglia there is now a large intraparenchymal hemorrhage. New mass effect with midline shift toward the right.

New left mesial temporal subcortical hemorrhage. Left midbrain and left parietal lobe hyperdense foci are suspicious for petechial hemorrhages. 

Stable intraventricular hemorrhage. Right frontal ICP monitor. 

Annotated image

Blue arrows demonstrate left basal ganglia petechial hemorrhages on the initial study, which has progressed into a large hemorrhage on the 24 hour follow-up study with new midline shift (green arrow).

Yellow arrows indicate small intraventricular hemorrhage, layering in the trigone. 

Case Discussion

Intermediary injuries are shearing hemorrhagic contusions from disruption of the lenticulostriate injuries affecting the basal ganglia or thalami. They are associated with diffuse axonal injury (DAI), which is almost certain in this case.

This case illustrates that the initial CT brain can have a collection of apparently minor/subtle injuries that evolve into more severe injuries. Also, DAI can often be occult or under called on CT. It should be remembered that CT provides only a "snapshot" in time. 

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Case information

rID: 47379
Published: 15th Aug 2016
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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