tn has only one cause,,,i respect others opinions,,,as to doctors,,,,its not them that suffer the pain,,they know no more than we do,,,tegretol allters brain chemistry,,,so does amonia,,,if you drink alchohol.it changes brain chemistry,,you feel less pain,,as your liver filters it out,nerve fuction returns to normal,,change brain chemistry for any reason,,and you nerve function changes,,tn is only a change in brain chemistry,thats all,,,because our brain and nerves do not change,,the liver and kidneys control brain chemistry,,,,if they dont work 100 percent,,,your in trouble,nuro toxins quickly build up,,in your blood stream,and enter your brain,if your bodies filter system is compromised in any way,,,it can cause tn,,,as brain chemistry changes,there is no great mystery to tn,,,brain chemistry is the cause,,its why little shows up in scans,,and is why tegretol works