Insular sclerosis, also known as multiple sclerosis (MS), is a chronic and unpredictable disease that affects the central nervous system. While the term "insular sclerosis" was previously used to describe the condition, it has now been replaced by "multiple sclerosis" to better reflect its complex nature. Synonyms for insular sclerosis include disseminated sclerosis and encephalomyelitis disseminata. These synonyms highlight the disease's characteristic feature of widespread damage to the myelin sheath surrounding nerve fibers in the brain and spinal cord. Understanding these synonyms helps to convey the various ways in which this debilitating disease has been referred to over time, contributing to a comprehensive comprehension of its history and current understanding.