What Diagnostic Finding is Likely for Patient With Sensation Changes?

A 28-year-old woman presents to the emergency department with sensation changes over a few days, including progressive numbness of her hands and legs. 

Her exam is noteworthy for mild weakness of elbow extension and hip flexion, normal muscle tone, diffusely brisk reflexes, and decreased sharp sensation with a sensory level at the mid chest. She denies recent illness or injury. 

A lumbar puncture is performed based on the imaging findings above.