Central myasthenia gravis refers to muscle ankylosis (spasticity) caused by a disease of the central nervous system. Myotonia is a group of muscle disorders that includes several types, such as ankylosing muscular dystrophy, congenital myotonia, congenital paraspinal myotonia, and symptomatic myotonia. In central nervous system diseases, the vertebral system is often damaged, often manifested as muscle ankylosis and spasticity, i.e. “central muscle ankylosis”. Symptoms can seriously affect motor function. Multiple sclerosis, amyotrophic lateral sclerosis, sequelae of surgery (spinal cord injury, brain injury), cerebellar degeneration of the spinal cord, cerebrovascular accidents, etc. can cause central muscle ankylosis.