canadian nurologist..said,,,,,,i beleive its ammonia,,,that causes tn,,,,and the quantities can be so low we cant measure it,,each individual can process only so much ammonia,,some may be supersensitive to it,,,but what we do know is,,,ammonia is a nerve exciter,,the one and only way tn can happen is a change in brain chemistry,,it is not the nerves themselfs,,it certainly is not a blood vessel,,,as billateral demostrates most clearly,,,there is no other naturaly occurring nerve exciter produced by our bodies,,,,only amonnia can do this,,,,as it does to horses and dogs,,,if we ignore tn in other species,we might as well put a blind fold on,and keep taking the meds,,,,,