Palilalia in sign language.

Sign languages, which use the hands and arms as articulators, are the natural languages of deaf people. Research indicates that sign, like speech, can break down at the level of motor control, in the context of a movement disorder such as Parkinson disease (PD).1 This article describes the first known case of a deaf sign language user with progressive supranuclear palsy (PSP). PSP affects the rostral brainstem and its projections to the basal ganglia, cerebellum, and cerebral cortex.2 Dysarthria typically emerges early in the course of the disease and disrupts several aspects of speech.3 The characteristic features of PSP dysarthria are articulatory incoordination and palilalia—the repetition of entire words at decreasing amplitudes without pause.2 This descriptive case study suggests that those same features are prominent in the sign production of a deaf man with PSP.