Speech-induced primary lingual dystonia: a rare focal dystonia.

Lingual dystonia, a type of focal dystonia that may be primary or secondary, is related to brain damage, neuroleptic use, neurodegenerative, metabolic, and neurodevelopmental disorders, varicella infection, and so on. However, primary lingual dystonia induced by speaking is a rare type of focal dystonia that is usually idiopathic in origin and is characterized by increased tonus of the tongue, which causes protrusion only during speaking. This report describes a 55-year-old male patient with lingual dystonia during speech. One interesting clinical feature of this case was that the speech disturbance improved while the patient vocalized a praise-like hymn in a manner that resembled singing.