Which condition involves loss of protective myelin sheath from nerve fibers in the central nervous system, leading to muscular weakness, coordination problems, and disturbances in skin sensation, speech and vision?

• A. Multiple Sclerosis
• B. Parkinson's Disease
• C. Cerebral Palsy
• D. Myalgic Encephalomyelitis (ME)

Answer: (A)

Demyelination in the central nervous system disrupts how nerve signals travel. In multiple sclerosis, the immune system attacks the protective myelin around nerve fibers in the brain and spinal cord, slowing or blocking conduction. This results in a range of neurologic symptoms depending on where the damage occurs, including muscular weakness, coordination and balance problems, sensory changes like numbness or tingling, and disturbances in speech and vision due to involvement of pathways that control these functions. The pattern and variability of symptoms reflect lesions scattered across the CNS and the body's attempts to compensate over time.

The other conditions involve different mechanisms: Parkinson's disease affects movement primarily from dopamine loss in the basal ganglia; cerebral palsy is a non-progressive motor disorder caused by early brain injury; myalgic encephalomyelitis (ME) centers on fatigue with other systemic symptoms rather than CNS demyelination.