Source : Webster's Revised Unabridged Dictionary (1913)

Thomsen's disease \Thom"sen's dis*ease"\ [From Thomsen, a
   physician of Sleswick.] (Med.)
   An affection apparently congenital, consisting in tonic
   contraction and stiffness of the voluntary muscles occurring
   after a period of muscular inaction.

Source : WordNet®

Thomsen's disease
     n : a mild, rare, congenital form of myotonia characterized by
         muscle stiffness [syn: {myotonia congenita}]