New-onset tic disorder following circumscribed brain injury

Adult-onset tics represent either a secondary tic disorder ("tourettism") or a late presentation of childhood tics, which may have been previously unrecognised. Head trauma has been recognised as an infrequent cause of adult-onset tic disorder, which exhibits variable temporal relationship to the inciting injury and response to therapy. We present a patient who presented with late-onset tics seven years after a circumscribed brain injury, responding well to antidopaminergic treatment. A review of all the previously reported cases of post-traumatic tic disorder is provided. Our patient is unusual in that the injury presumed to be responsible for the development of tics was of a very focal nature, akin to previously described tic disorder following vascular insults. We discuss the rare occurrence of tourettism after such focal brain lesions and analyse the insights this provides into the anatomical substrates underlying tic disorders.