What is the term for the shrinkage of muscle following paralysis?

The term for the shrinkage of muscle following paralysis is best described as pathological atrophy. Pathological atrophy refers to muscle wasting that occurs as a result of disease or pathological conditions, such as paralysis. When a muscle is not subjected to regular use, as in the case of paralysis where nerve impulses are interrupted, it cannot maintain its size and strength, leading to shrinkage or atrophy.

In contrast, physiological atrophy generally refers to the natural reduction in size of muscles that can occur with aging or disuse, but it is not typically directly associated with a pathological condition like paralysis. Muscle degeneration usually refers to a broader category of changes that may include damage to muscle fibers beyond just atrophy, and sarcopenia specifically denotes age-related muscle loss, which differs from the context of paralysis. These distinctions clarify why "pathological atrophy" is the most accurate choice in this situation.