I Am Having Numbness\ Tingling On One Side Of My

I am having numbness\ tingling on one side of my face. also twitching around eye and mouth. has been going on since early August. was about once a week. has become more frequent. happened twice this morning.
I have a acoustic neuroma that has damaged my left hearing. had radiation therapy 5 years ago to kill tumor.
what could be causing numbness and twitching? My ENT told me in august over the phone that it was probably a virus...