The person in Oliver Sacks writings who had Tourette's
(mentioned by Mark C. a'bove) was a very acomplished surgeon,
if i recall correctly, and was able to maintain control
over his symptoms of the syndrome, in order to perform
difficult surgeries. In the periods of rest between
these intense sessions, he needed to allow his body
to sit, sprawl, stretch out and in various ways
relax from the effort of keeping it all together
in between times.

http://www.oliversacks.com/

you can see references to his writings on Gilles de la Tourette Syndrome

if you look up on the Subject (alphabetical) page.

good luck, and i jsut thought it might be helpful
to see a case study about a person who did not
let their condition stop them from being successful.