[Encephalitis caused by cold sore virus?]

I was told yesterday by a nuerologist that I have encephalitis, and probably have had since birth.

All my life I have suffered from a skin virus around my eye which is apparently related to cold sores, and as a child I was given smallpox vaccinations every year to help control the frequency of the rash.

Could this have caused the encephalitis, and should I worry? The nuero said not to worry, but the google search I have done screamed 'serious!'