Rapidly Progressive Extremity Weakness in a 3-year-old Girl

A previously healthy 3-year-old girl presents with acute onset of bilateral lower extremity weakness. The patient was doing well until this morning, when the mother found her daughter outside of her crib on the floor. It was not unusual for the patient to climb out of her crib, and the mother denies hearing a fall. Subsequently, the child was unable to stand or move her legs. She also reported no sensation in her feet after the mother attempted to prick her. Assuming the child had a fall, which caused her symptoms, the mother took her to a nearby emergency department. The mother denies any recent immunizations, fever, upper respiratory tract infections, vomiting, diarrhea, or sick contacts. No history of headaches or concerns for vision or hearing changes are reported by the mother. Her additional complaints include not having passed stool for 2 days and having intermittent abdominal pain on the...