Myotonic disorders

Definition

Group of inherited muscular disorders associated with clinical and/or electrical myotonia. Myotonia is defined clinically as the occurrence of “delayed relaxation of muscle after voluntary contraction or percussion.”

8 subordinate codes

• 8C71.0Myotonic dystrophy
• 8C71.1Chondrodystrophic myotonia
• 8C71.2Myotonia congenita
• 8C71.3Drug-induced myotonia
• 8C71.4Neuromyotonia
• 8C71.5Pseudomyotonia
• 4B4YOther specified diseases of the immune system
• 4B4ZDiseases of the immune system, unspecified

Nearby in Primary disorders of muscles

• 8C70Muscular dystrophy
• 8C72Congenital myopathies
• 8C73Mitochondrial myopathies
• 8C74Periodic paralyses or disorders of muscle membrane excitability
• 8C75Distal myopathies
• 8C76Myofibrillar myopathy
• 8C77Ocular myopathy
• 8C78Malignant hyperthermia or hyperpyrexia