Paroxysmal nonkinesigenic dyskinesia
（重定向自Mount Reback syndrome）
Paroxysmal Nonkinesigenic Dyskinesia (PNKD) is an episodic movement disorder first described by Mount and Reback in 1940 under the name "Familial paroxysmal choreoathetosis". It is a rare hereditary disease that affects various muscular and nervous systems in the body, passing to roughly fifty percent of the offspring.