How does multiple sclerosis typically present and what is a key diagnostic feature?

• A. Absence of brain lesions on MRI
• B. Peripheral demyelination only in nerves
• C. Blood glucose abnormalities
• D. MRI shows periventricular white matter plaques due to demyelination

Answer: (D)

Multiple sclerosis is an autoimmune process that damages myelin in the CNS. It most often presents as episodes of neurologic symptoms that involve different areas of the CNS and recur over time—for example vision changes, weakness, numbness, or coordination problems—that occur at different times and in different locations.

A key diagnostic feature is the MRI finding: multiple demyelinating lesions in the brain, most characteristically in the periventricular white matter. These periventricular plaques reflect areas of myelin loss and are a hallmark of MS. Active inflammation can make some lesions enhance with gadolinium during a relapse.

The other options don’t fit MS: lack of brain lesions would be inconsistent with the typical MRI pattern; MS is a central nervous system disease, not peripheral demyelination; and blood glucose abnormalities are not part of its diagnostic picture.