Curriculum · Neurology
Herpes simplex (viral) encephalitis
What it is
The most common cause of sporadic encephalitis is HSV-1. Herpes simplex is a common viral infection whose two types sit in different places, HSV 1 at the mouth and nose and HSV 2 at the genitalia, buttocks and thighs; and among the viral causes of meningitis, HSV-2 is the one listed while HSV-1 is set against it as the cause of encephalitis. One page gives herpes encephalitis to both HSV-1 and HSV-2, and another gives encephalitis to HSV-1 and meningitis to HSV-2, so the tie of the type to the picture is written one way in one place and the other way in another.
How it presents
The clinical picture is fever, altered sensorium, seizure and focal neurologic deficit. Set out as a list of what points to it:
- A young or an old patient.
- New onset seizure.
- Change in personality, or hallucinations.
Hemorrhage of the temporal lobe belongs to the same picture, and VZV is kept in mind alongside it, marked by its vesicle.