How does the immune system affect patients with Multiple Sclerosis?

The immune system in patients with Multiple Sclerosis (MS) plays a detrimental role by attacking the myelin sheath of neurons. This myelin sheath is a protective covering that insulates nerve fibers, facilitating the rapid and efficient transmission of electrical impulses along the nerves. In MS, the body's immune response mistakenly targets and damages this sheath, leading to inflammation and the formation of lesions in the central nervous system. As a result, the communication between the brain and other parts of the body is impaired, which can lead to various neurological symptoms such as fatigue, difficulty with coordination and balance, and cognitive changes.

The other options do not accurately describe the effects of the immune system in MS. For instance, while stimulation of neural regeneration may be a goal in neuroprotection strategies, it is not an outcome of the immune response in MS. An increase in the number of neurons or neurotransmitter availability is not characteristic of the MS pathology, as the disease primarily involves demyelination and neuronal damage rather than regeneration or enhancement of neural activity. Thus, the primary mechanism involves the immune-mediated attack on myelin, which is encapsulated in the correct choice.