outweigh the benefits. if necessary, however, symptoms of the disorder may be relieved with quinine, ranolazine, procainamide, flecainide, phenytoin, carbamazepine, mexiletine and other anticonvulsant drugs. physical therapy and other rehabilitative measures may also be used to help muscle function. genetic counseling is available. epidemiology in northern scandinavia, the prevalence of myotonia congenita has been estimated at 1:10,000. myotonia congenita is estimated to affect 1 in 100,000 people worldwide. research the name thomsen’s disease refers to the danish physician julius thomsen (1815–1896) who described the condition in himself and his family. myotonia can be achieved in preparations of intact isolated muscle by the administration of 9-anthracenecarboxylic acid, a blocker of chloride channels. it is also possible to achieve myotonia in preparations of intact isolated muscle by greatly lowering or removing the extracellular content of chloride in the bathing medium. during the 1970s several murine models of myotonia appeared. one in particular has been used widely, the adr mouse or "arrested development of righting response". this model is often used in scientific work with muscular dystrophy, and displays myotonia due to lack of functional chloride channels.