Which examination finding would most likely occur with Guillain-Barré syndrome?

• A. Hypertonicity in the affected muscles
• B. Clonus with rapid passive foot dorsiflexion
• C. Diminished tendon reflexes
• D. Ataxic gait pattern

Answer: (C)

Guillain-Barré syndrome is a peripheral nerve disease that disrupts the reflex arc. When the nerves supplying muscles are inflamed and their conduction slowed or blocked, the deep tendon reflexes become diminished or absent. This loss of reflexes—hyporeflexia or areflexia—is a hallmark feature of GBS as the autoimmune process affects the peripheral nerves rather than the brain or spinal cord.

In contrast, signs like hypertonicity or clonus point to upper motor neuron pathology, where the opposite problem occurs (increased tone and exaggerated reflexes). An ataxic gait can occur in various conditions, but the clear, characteristic exam finding in this syndrome is the reduced reflex responses.