Which option describes the formation of plaques or lesions in MS?

Which option describes the formation of plaques or lesions in MS?

• A. Lewy bodies in substantia nigra
• B. Plaques or lesions due to demyelination
• C. Neurofibrillary tangles
• D. Amyloid plaques in cortex

Answer: (B)

In multiple sclerosis, the defining changes are patches of demyelination in the CNS. These plaques form when the immune system attacks myelin, stripping it from white-matter tracts and leaving areas of slowed or blocked nerve conduction. Over time, these demyelinated patches become scarred with gliosis, reinforcing the lesion. This pattern of demyelinating plaques is what gives MS its characteristic clinical episodes and neurological deficits. Other options describe processes or plaques associated with different diseases (for example, Lewy bodies in Parkinson’s disease or amyloid plaques and neurofibrillary tangles in Alzheimer’s disease), which are not the hallmark of MS.

In multiple sclerosis, the defining changes are patches of demyelination in the CNS. These plaques form when the immune system attacks myelin, stripping it from white-matter tracts and leaving areas of slowed or blocked nerve conduction. Over time, these demyelinated patches become scarred with gliosis, reinforcing the lesion. This pattern of demyelinating plaques is what gives MS its characteristic clinical episodes and neurological deficits.

Other options describe processes or plaques associated with different diseases (for example, Lewy bodies in Parkinson’s disease or amyloid plaques and neurofibrillary tangles in Alzheimer’s disease), which are not the hallmark of MS.