Synonym: miryachit. ... Origin: Kalmuk? ... (05 Mar 2000) ... 
(mir-yah´chit) [Russ.] a variety of jumping disease seen in Siberia, possibly identical to latah. Spelled also miryachit.
myriachit, miryachit A form of bizarre repetitive and widespread habit spasm affecting many members of a community, often in an imitative way. It has been described in Java, Borneo, and in parts of Russia. Etymology: Russian, from Greek myrios, 'countless'.