Which statement about multiple sclerosis is accurate?

Relapsing-remitting is indeed the most common form of multiple sclerosis (MS), accounting for approximately 85% of cases at onset. This type of MS is characterized by periods of acute exacerbation, or relapse, followed by periods of recovery or remission where symptoms improve or stabilize. During the relapsing phase, patients may experience a variety of neurological symptoms due to inflammation and demyelination of nerve fibers in the central nervous system. The fundamental nature of relapsing-remitting MS is a cyclical pattern of symptom flare-up and recovery, which contrasts sharply with other forms of the disease, such as primary progressive MS.

In contrast, other statements present inaccurate information regarding multiple sclerosis. The onset of the disease typically occurs in young adulthood, most often between the ages of 20 and 40, not 60-80. The breakdown of axons occurs later in the disease process as the condition progresses, primarily as a result of demyelination, rather than being the initial step. Finally, spinal forms of MS often contribute to bowel and bladder dysfunction as a result of neurological involvement, rather than rarely causing these issues. These aspects clarify why the characterization of relapsing-remitting as the most common form is accurate.