Herpetic encephalitis

Case contributed by Dr Maxime St-Amant


Confusion. No focal neurological symptoms. R/o stroke.

Patient Data

Age: 75 years
Gender: Male

NECT shows medial temporal / insular hypodensity with slight local mass effect, without hyperdense MCA or basal ganglia hypodensities. This patient was further investigated with brain MRI.


There is diffusion restriction on the DWI sequence involving the insular cortex and medial temporal region, with sparing of the basal ganglia, as mentionned previously. This phenomenon is unilateral in this case. Corresponding hypersignal on FLAIR and hyposignal on T1.

Although more frequently bilateral and symmetric, this cases demonstrates acute ischemia involving the right insular and temporal lobes, with sparing of the ipsilateral basal ganglia, compatible with herpes simplex encephalitis.

Case Discussion

The patient was treated for herpes encephalitis with acyclovir and symptoms partially relapsed.

The main differential diagnosis for this pattern are:

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Case information

rID: 18927
Published: 28th Jul 2012
Last edited: 3rd Jul 2020
Inclusion in quiz mode: Included

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