A 15-year-old boy presents to the ED complaining that she cannot walk. She has been in her normal state of health except for an episode of nausea, vomiting and diarrhea 15 days ago. On exam, she has decreased strength in her bilateral lower extremities with absent patellar and ankle jerk reflexes. What is the next step in management of this patient?

A. Lumbar puncture

B. MRI Spine

C. MRI Brain

D. Vital Capacity

E. Electromyography

Answer: D

-This patient has Guillain-Barre Syndrome (GBS), an immune-mediated peripheral neuropathy. It is often preceded by a viral illness like C.jejuni or vaccination.

-Clinical: ascending symmetric weakness or paralysis with decreased or absent deep tendon reflexes.

-The most serious complication is respiratory failure from diaphragmatic involvement so measure vital capacity and negative inspiratory force (NIF) is critical.

-Lumbar puncture would show albuminocytologic dissociation

-Management: airway protection guided by vital capacity and NIF + supportive measures + IVIG and/or plasmapheresis

-Disposition: ICU