A patient with progressive paresthesias and areflexia; CSF shows protein 70 mg/dL and cell count 5/µL. What is the mechanism behind this condition?

A patient with progressive paresthesias and areflexia; CSF shows protein 70 mg/dL and cell count 5/µL. What is the mechanism behind this condition?

• A. Axonal degeneration without demyelination
• B. Central demyelination
• C. Destruction of myelin with endoneurial lymphocytic infiltrates
• D. Motor neuron loss

Answer: (C)

This pattern reflects an immune-mediated peripheral demyelination, classically Guillain-Barré syndrome. The autoimmune attack targets the myelin sheaths of peripheral nerves, leading to demyelination with slowed conduction and impaired sensation and reflexes. Inflammation focuses within the nerve’s endoneurial space, with lymphocytes present around the damaged myelin. The CSF finding of elevated protein with a near-normal cell count—albuminocytologic dissociation—fits this demyelinating process, arising from breakdown of myelin and the blood-nerve barrier rather than inflammatory cells flooding the CSF. So, the best mechanism is destruction of myelin with endoneurial lymphocytic infiltrates. This distinguishes it from axonal degeneration, central ( CNS ) demyelination, or motor neuron loss.

This pattern reflects an immune-mediated peripheral demyelination, classically Guillain-Barré syndrome. The autoimmune attack targets the myelin sheaths of peripheral nerves, leading to demyelination with slowed conduction and impaired sensation and reflexes. Inflammation focuses within the nerve’s endoneurial space, with lymphocytes present around the damaged myelin.

The CSF finding of elevated protein with a near-normal cell count—albuminocytologic dissociation—fits this demyelinating process, arising from breakdown of myelin and the blood-nerve barrier rather than inflammatory cells flooding the CSF.

So, the best mechanism is destruction of myelin with endoneurial lymphocytic infiltrates. This distinguishes it from axonal degeneration, central ( CNS ) demyelination, or motor neuron loss.