Occam versus Hickam.

A 23-year-old man presented with new onset horizontal diplopia 5 months after a left orbital floor fracture. Examination revealed bilateral abduction deficits and disc swelling. Urgent MRI and MRI showed no significant abnormalities in the CNS. Lumbar puncture revealed a minimally elevated opening pressure and significant leukocytosis. Additional CSF testing revealed probable Lyme meningitis. The patient responded to a course of oral doxycycline, with rapid resolution of his diplopia, abduction deficits, and disc edema.