Review Question - QID 213678

A 33-year-old man presents to the emergency department with weakness. He states that he recently returned from a hiking trip and was acutely ill afterwards with nausea, vomiting, and diarrhea. After his symptoms resolved, he then began to experience weakness in his legs that has been worsening. The patient is otherwise healthy and does not have any other medical conditions. His temperature is 98.0°F (36.7°C), blood pressure is 122/87 mmHg, pulse is 83/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam is notable for 2/5 strength of the patient’s lower extremities with absent Achilles tendon reflexes and 1+ patellar tendon reflexes. A CT scan of the head is performed and is unremarkable. A lumbar puncture is subsequently performed. Which of the following is most likely to be seen on lumbar puncture and cerebrospinal fluid (CSF) analysis?