15th August 2024

You are asked to see a patient in ED who has presented with bilateral lower limb weakness and confusion

You are asked to see a patient in ED who has presented with bilateral lower limb weakness and confusion. He is a 32-year-old man who has recently returned from a prolonged trip to the United States, where he has spent the summer hiking part of the Appalachian Trail. He transited through New York on his return journey.

He is unable to give much history and is not oriented to time, person, or place. His flatmate reports that he returned the day before yesterday and had complained of mild viral symptoms and headache on arrival, followed by rapid progression of weakness in his lower limbs, accompanied by disorientation.

His observations are remarkable for a temperature of 38.1℃. On examination, his GCS is 14 (E4V4M6). You note an asymmetrical weakness in the lower limbs. There is mild photophobia but no cranial nerve signs. There is a truncal rash, which is maculopapular.

Which is the single most likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.