MRCP2-2866

A 35-year-old woman presents to the Emergency department with weakness in both legs and a feeling of general malaise. She had recently returned from a four week trip to Eastern Europe. During examination, she appeared unwell and had a fever of 38.9°C. Large cervical lymph nodes were palpable on both sides of her neck, and her pharynx was inflamed with exudate on the pharyngeal wall. Neurological examination revealed global weakness in both legs and absent reflexes. What is the most likely diagnosis?