A 55-year-old patient presents with progressive weakness, sensory loss, and impaired motor coordination. MRI findings demonstrate patchy areas of demyelination within the brainstem and cervical spinal cord, while nerve conduction studies also reveal delayed impulse transmission in peripheral nerves. The provider suspects a disorder affecting myelin integrity at the transition zones between the central and peripheral nervous systems. Which explanation best integrates the underlying pathophysiologic mechanism contributing to this patient's neurologic findings?