Mutism in a patient with Gilles de la Tourette syndrome.

A 5-year-old boy with a prior history of stuttering presented to the neuropaediatrics clinic with prominent motor and vocal tics, including intrusive syllables, was diagnosed with Gilles de la Tourette syndrome (GTS). One month later, near-complete mutism developed acutely, which improved progressively after treatment with risperidone. During the follow-up, motor and vocal tics fluctuated concurrently, but without clear-cut mutism. GTS encompasses a range of vocal tics, including vocal-blocking phenomena, which made us postulate that this case may represent an extreme expression of vocal blocking tics.