congenital paramyotonia

n.
  1. A nonprogressive disease characterized by myotonia induced by exposure to cold, with episodes of intermittent flaccid paralysis but no atrophy or hypertrophy of muscles.Eulenburg's disease
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.