ICD-10-CM > G00-G99 > G70-G73 > G71 > G71.1 > G71.19 G71.19 Other specified myotonic disorders Billable/Specific Copy Code Copy Description Applicable To Myotonia fluctuansMyotonia permanensNeuromyotonia [Isaacs]Paramyotonia congenita (of von Eulenburg)PseudomyotoniaSymptomatic myotonia