Which description best characterizes Guillain-Barré syndrome?

• A. Immune-mediated peripheral neuropathy with destruction of Schwann cells and neurons.
• B. Central nervous system demyelination with cognitive impairment.
• C. Autoimmune attack on acetylcholine receptors at the NMJ.
• D. Autoimmune attack on presynaptic calcium channels at the NMJ.

Answer: (A)

Guillain-Barré syndrome is an acute autoimmune process that mainly targets the peripheral nerves. The immune system attacks the myelin sheath produced by Schwann cells, leading to demyelination and disrupted nerve conduction. This peripheral nerve damage causes the characteristic ascending weakness and reduced or absent reflexes. Since the problem lies in the peripheral nervous system, central demyelinating diseases of the brain or spinal cord would present differently, and conditions like myasthenia gravis or Lambert-Eaton involve the neuromuscular junction, not Schwann cell–mediated peripheral demyelination. So the description best fitting Guillain-Barré is an immune-mediated peripheral neuropathy with destruction of Schwann cells and the myelin they form.