"Signing tics"--insights into the pathophysiology of symptoms in Tourette's syndrome.

We describe the case of a young woman with Tourette's syndrome who incorporated sign language into her tic behavior. Sign language was used in complex "phonic tics" such as swearing, echoing what others said, or repeating what she said, read, or thought. We suggest the descriptive terms "coprolaliopraxia," "echolaliopraxia," and "palilaliopraxia" to denote these symptoms. The incorporation of such complex, learned movements into the repertoire of hyperkinesias further emphasizes the complicated association between purposeful and automatic execution of movements comprising tic behavior. This case also provides strong evidence against the suggestion that obscenities vocalized in Tourette's syndrome are due to a random generation of high-probability sequences of letters or phonemes.