A 56-year-old woman is referred to the neurology clinic for evaluation of her long-term problem of a stumbling gait and a tendency to fall. Her visual acuity also seems to change periodically. Neurological findings suggest multiple sclerosis. This diagnosis is further supported by magnetic resonance imaging, which shows of areas of demyelination in the central nervous system. Other tests show the presence of oligoclonal bands in the spinal fluid. The loss of myelin from a nerve fiber has which of the following effects?

Question

Quizplus · Accepted Answer

The loss of myelin from a nerve fiber results in decreased conduction velocity of action potential or no action potential. This is because myelin serves as an insulator and allows for faster conduction of impulses along the nerve fiber. Without myelin, the impulses are slowed down or unable to propagate, leading to neurological symptoms such as those seen in multiple sclerosis.

A 56-Year-Old Woman Is Referred to the Neurology Clinic for Evaluation