Adult onset tics after peripheral injury.

We describe a case with adult onset motor tics after peripheral trauma. A 43-year-old man suffered a left shoulder dislocation during a motorcycle accident 21 years ago. Within 2 weeks after the injury, he noticed the gradual onset of involuntary jerking movements of his left shoulder, which was markedly exacerbated after second left shoulder injury 2 years later. The involuntary movements are phenomenologically identical to tics typically associated with Tourette syndrome (TS), but without the involvement of any other body part and without phonic tics or the typical TS co-morbidities, such as attention deficit or obsessive-compulsive disorder.