Formally it's Tourette, not Tourette's. Bwahahahaha. ;-)
Tourette syndrome (also called Tourette's syndrome, Tourette's disorder, Gilles de la Tourette syndrome, GTS or, more commonly, simply Tourette's or TS)...
Actually, it's Tourette syndrome, but Tourette's is also acceptable. ;-)
http://en.wikipedia.org/wiki/Tourette_syndrome