Amantadine and TBI

Has anybody out there experienced a dramatic effect after being prescribed Amantadine for TBI? After a clipping of PCOM aneursym I became increasing fatigued and apathetic- to the point of being close to non-functional. Testing showed I now have a verbal learning deficit, but my MRI is normal. A neurologist decided to treat it as TBI and prescribed the Amantadine. He said it might improve my memory, but what actually happened was a huge change in perception and the disappearance of the fatigue.  I felt a "wave" go through my head the first dose follwed by a odd perceptual change. By the second dose I suddenly felt everything around me was "real" again. My  neurologist was surprised when I described my reaction to the medication. I know Amantadine can effect dopamine levels, but little else about it's use in TBI.  Was my reaction that unusual? Do low dopamine levels normal cause the symptoms I had?