Presentation
Unexplained loss of consciousness.
Patient Data

The exam was read as normal, with preserved white - gray matter differentiation. No sign of intracranial hypertension.
The patient remained unconscious. No clinical explanation. EEG still shows cerebral activity.

CT-scan shows a diffuse supra- & infra-tentorial loss of grey-white matter differentiation, without sign of intracranial hypertension. The ventricles have a normal caliber. No signs of herniation.

There is an extensive loss of grey-white matter differentiation, with important brain swelling. Note that the parenchyma is extensively hypodense (around 20-25 HU).
There a many signs of intracranial hypertension in this patient with extensive, progressive, cerebral edema :
- effaced sulci
- slit-like third & fourth ventricles, with reduction of the lateral ventricles caliber compared to previous examinations
- supra-sellar cistern obliteration (uncal herniation)
- cerebellar tonsils hernation
No intracranial hemorrhage.
Case Discussion
When reviewing CT scans in patients who are unconscious one has to be carefully assess for early grey white matter differentiation loss, keeping in mind that as with other forms of infarction, CT features may take some time to become evident.