motor speech disorder caused by damage to the basal-ganglionic circuit, most commonly seen in Parkinson’s disease and other conditions accompanied by dopamine deficiency. It is characterized by a reduced amplitude and speed of movements, monotonous pitch and volume of the voice, a changeable tempo (often with rapid “raids” of speech) and inaccurate articulation. Additional signs may include a breathless or hoarse voice, decreased expressiveness, and a “mask-like” facial expression.