Jens, I am currently on a ketogenic diet and can relay the positive results I have been getting:
Previously I would have extreme random thoughts, especially in conversation with others. I would also find myself saying random weird and inappropriate things while conversing with others. This condition was not debilitating for me and in fact not actually too traumatic due to the fact that I would rationalise these occurrences as being just me and the special way my creative brain worked, this I discovered was not actually the case. My randomness was not too rude, just wildly off topic, and though my thoughts were extreme they went unbeknownst to others, I would also take some solace in the fact that these extreme thoughts were my own and private. So I was managing fully and 'this condition ' as I now call, it went completely untreated. Well after water fasting for 5 days and then two weeks after going through a pretty hard switch over to full ketogenic brain functioning (90% fat 8% protein and 2% carbs) I can tell you my thoughts are calm and my conversations are focused and on topic. The condition that I did not know I had until it was gone has left me for good, when it left I noticed a quiet, a silence of my mind, a calm space where I can control my thoughts at will, and I feel very energetic on this diet.
The sideways randomness of my former condition suggests to me some dopamine misbehaviour, I am still able to be creative but its far more controlled, focused and directed.
I hope my experience here can be of some help to those suffering from full tourette's and that even if some have invested much time and energy forming new neural pathways for triggers to follow that they will consider this. Yes its hard but once I was fully on the diet I found a new energy and clarity of mind thats makes the transition worth the wait. BTW if you believe the hype about saturated fat being bad for your heart, this diet is not for you, however if you have through research come to understand that saturated fat on this diet is actually good for you and that high total cholesterol is good for you too then it can actually be a fun diet, think loads and loads of butter, cream, cheese cheese cheese and many other savoury delights, oh and remember to add lots of salt. Always the opposite right!