Isolated syndrome, often also called clinically isolated syndrome, is a first-ever, monochronic, single- or multifocal demyelinating disease of the central nervous system. Clinically isolated syndrome usually occurs when the myelin sheaths that surround neurons are attacked by the autoimmune system, resulting in symptoms associated with the failure of these myelin-associated neurons to function properly. The exact cause of this occurrence is currently unknown. Clinically isolated syndrome has the same symptoms as multiple sclerosis, usually characterized by limb weakness, sensory abnormalities, ataxia, vertigo, and fatigue. However, the number of episodes is different, as MS usually has two or more episodes, whereas clinically isolated syndrome only has a single episode. If a patient is diagnosed with isolated syndrome, it is recommended that he or she go to a hospital in a timely manner and receive standardized treatment under the guidance of a medical professional.