Percussion Myotonia

Video Author: Richard J. Barohn, MD, FAAN
Created on: 12.31.2013
Associated with: CONTINUUM: Lifelong Learning in Neurology. 19(6, Muscle Disease):1598-1614, December 2013

Video demonstrates the clinical evaluation of percussion myotonia over the extensor digitorum communis. A fast strike with the reflex hammer over the extensor digitorum communis produces the characteristic extension of the fingers and wrist, with subsequent myotonic catch and delay of muscle relaxation.

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