After recovering from a viral respiratory tract infection, a 23-year-old female presents with weakness in her distal extremities that rapidly ascends to involve proximal muscles. Physical examination reveals absent deep tendon reflexes, and a lumbar puncture reveals the CSF protein to be increased, but very few cells are present. A biopsy of a peripheral nerve reveals inflammation and demyelination (radiculoneuropathy). What is the best diagnosis?

Inflammatory polyneuropathies may be acute or chronic. Acute inflammatory demyelinating polyradiculoneuropathy (Guillain-Barre syndrome) is a life-threatening disease of the peripheral nervous system. The disease usually follows recovery from an influenza-like upper respiratory tract infection and is characterized by a motor neuropathy that leads to an ascending paralysis that begins with weakness in the distal extremities and rapidly involves proximal muscles. Sensory changes are usually minimal. The disease is thought to result from immune-mediated segmental demyelination. In rare patients, instead of an acute course, Guillain-Barre syndrome takes a chronic course with remissions and relapses. This process is called chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Reference: Robbins & Cotran Pathologic Basis of Disease, 9edition