What is infantile-onset ascending hereditary spastic paralysis?
Infantile-onset ascending hereditary spastic paralysis is a rare disorder characterized by progressive weakness and stiffness of muscles in the arms, legs, and face. This disorder damages motor neurons, which are specialized nerve cells in the brain and spinal cord that control muscle movement. Initial symptoms of infantile-onset ascending hereditary spastic paralysis usually occur within the first 2 years of life. These symptoms include weakness of the legs, leg muscles that are abnormally tight and stiff, and eventual paralysis of the legs. People with infantile-onset ascending hereditary spastic paralysis are usually wheelchair-bound by late childhood or early adolescence. Over time, muscle weakness and stiffness travels up (ascends) the body from the legs to the head. By late childhood or early adolescence, arm and hand muscles are affected. Muscles in the neck and head usually weaken during adolescence; symptoms include slow eye movements and difficulty with speech and swallowing.
