all this surgery..and drugs.doctors give out,,may,,not be necccesary,,,it could be down to how the individual is able to process amonnia,,,,even the smallest amount will cause damage,,somwhere in the body,,,,its said tn is an old persons desease,,,may be because thier livers and kidneys no longer work as efficiently as before,,,you can read thousands of posts about tn,,,,but no where will you find a cure let alone the cause,,and there has to be a cause,,,for me,i have no doubts its amonnia,,,,because my liver is damaged,,,,but you dont need liver damage to have high amonnia levels,,you may just be supersensitive to even the smallest amout,,which wont show in blood tests,,,