PARAMYOTONIA is a congenital and inherited muscle disorder manifested by spontaneous contraction and paresis of various muscle groups upon exposure to cold. It represents the rarest of the group of muscular diseases known as myotonias, which also includes myotonia congenita, or Thomsen s disease, and myotonia dystrophica.
HISTORY AND INCIDENCE
Thomsen in 1876 1 published his treatise on myotonia and traced the disease in his own family as far back as 1742. Erb's classic monograph appeared in 1886,2 describing the clinical picture and basic electromyographic findings in myotonia congenita. Simultaneous.y with Erb's work, Eulenberg,3 in 1886, described a family in which a form of myotonia occurred in the affected members only after exposure to cold, and he termed the condition paramyotonia. The muscle affection involved some 29 persons, traced through six generations, and by 1916 it had been traced through eight generations. The condition was manifested by tonic