My Mom Went To Neurologist Monday Because She Was Experiencing

My mom went to neurologist Monday because she was experiencing pain in her left back side of her head. She got into an ATV accident five years ago and her tenderness just started three months ago she's been getting shaky and loss of vision vertigo etc. the neurologist told us that she is missing a part of her skull gave her gabapentin and that is it? is there anything else we can do or anyone else we can go to we were very unsatisfied with his diagnosis?