Tourette syndrome (TS or simply Tourette's) is a common neuropsychiatric disorder with onset in childhood,characterized by multiple motor tics and at least one vocal (phonic) tic. These tics characteristically wax and wane, can be suppressed temporarily, and are typically preceded by an unwanted urge or sensation in the affected muscles. Some common tics are eye blinking, coughing, throat clearing, sniffing, and facial movements. Tourette's does not adversely affect intelligence or life expectancy.
there is a movie about this,Front of the Class (2008).