Guillain-Barré syndrome is characterized by which pattern of weakness?

• A. Descending flaccid paralysis
• B. Peripheral neuropathy with sensory loss
• C. Acute mental status changes
• D. Ascending symmetric paralysis

Answer: (D)

Guillain-Barré syndrome shows weakness that starts in the legs and moves upward in a symmetric pattern, often reaching the arms and sometimes the face. This ascending symmetric paralysis happens because the autoimmune attack targets peripheral nerves diffusely, leading to widespread weakness with reduced or absent reflexes. Sensory symptoms can occur, but the defining feature is the progressive, symmetric ascent of weakness.

This differs from conditions with descending weakness (such as botulism) and from scenarios where mental status changes are prominent. While peripheral neuropathy can involve sensory loss, the hallmark here is the orderly, ascending, symmetric paralysis that can progress to involve breathing if severe.