A patient develops rapidly progressive, ascending, symmetric muscle weakness with loss of reflexes a few weeks after a respiratory infection. This acute inflammatory demyelinating polyneuropathy is:

Guillain-Barre syndrome is an acute autoimmune demyelinating polyneuropathy, often post-infectious, causing ascending symmetric weakness and loss of reflexes; severe cases threaten the respiratory muscles and are a medical emergency.Other options: Bell palsy is a unilateral facial-nerve palsy; trigeminal neuralgia is episodic facial pain; myasthenia gravis causes fatigable weakness (ptosis, diplopia), not ascending areflexic paralysis.Key exam takeaway: Ascending symmetric weakness with areflexia after an infection = Guillain-Barre; watch respiratory status.