Whipped out my copy of Beneson's "Control of Communicable Diseases in Man."

Viral meningitis is also called aseptic meningitis, Serous meningitis, Non-bacterial or Abacterial meningitis.

A relatively common but rarely serious cinical syndrome with multiple viral etiologies [causes]...

The book does say there are sometimes residual signs lasting a year or more, but (paraphrasing) this is rare.

It also says "Active illness seldom exceeds 10 days," and "Recovery is usually complete."

From the Centers for Disease Control and Prevention, a fact sheet on Viral (aseptic) Meningitis.