What exactly would the symptoms of such brain damage even be? Based on what I can scrounge from a quick Google search, they'd probably be loss of non-anger emotions, loss of survival instinct, loss of smell at the mental level so you can't even imagine smells anymore, loss of personality, and loss of sapience. Also the inability for even stem cell therapy to fix the damage.
And does the virus even need to be in the brain for the damage to occur? Or is its entry to the brain as inevitable as death and taxes?