Herpes Simplex virus (HSV) encephalitis

Case contributed by Dr Mohammad A. ElBeialy


Disturbed level of conciousness and fever.

Patient Data

Age: 90 years
Gender: Female

A patchy hypodensity is noted within the right medial temporal lobe with slight mass effect on the right lateral ventricle's temporal horn.

Atrophic brain changes with periventricular hypodensities.

The medial temporal lobe as well as the right insula shows a patchy areas of abnormal signal intensity with hypointense T1 and hyperintense T2 and FLAIR signal intensity. Hyperintense DWI signal with no correlated hypointense ADC signal lying it is a T2 shine through and not a true restricted diffusion. 

Atrophic brain changes with periventricular arteriosclerotic leucoencephalopathy and bilateral cerebral deep white matter chronic lacunar ischemic foci (small vessel disease). 

right otomastoiditis with T2 prolongation is incidentally noted.

Case Discussion

Herpes simplex virus (HSV) encephalitis typically appears as bilateral asymmetrical involvement of the the medial temporal lobe, the limbic system; the insular cortex and the inferolateral cortical sulci. However, unilateral involvement is not quiet uncommon.

Sparing the basal ganglia; namely the putamen differentiates the HSV encephalitis from the middle cerebral artery (MCA) infarction.

PlayAdd to Share

Case information

rID: 38583
Published: 9th Feb 2016
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.