This article includes Supplementary Video, available online at .

jws-mds.20524.vid.mpg8006K Bilateral episodic, synchronous, myoclonic twitching of both platysmal muscles, non-suppressible and not related to movement. Note the small diffuse goiter and the absence of involvement of other facial muscles, ruling out bilateral hemifacial spasm. This video presentation has been abbreviated. The full version will appear on theMovementDisorders DVD Supplement, which is issued bi-annually.

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