Uncontrollable repetition of a particular response, such as a word, phrase, or gesture, despite the absence or cessation of a stimulus, usually caused by brain injury or other organic disorder.

• 持续症，言语重复症：对一种特定的反应难以控制的重复，如一个词、短语或手势，尽管没有受刺激或终止刺激，通常由脑部受伤或其他器官的紊乱引起