A 55-year-old woman with no medical history was doing housework when a sudden, intense pain wrapped around her mid-back like a belt. Within four hours she could not move her legs at all.
By the time she reached the emergency department, her lower limbs were completely paralyzed while her cranial nerve function remained intact. She had lost pain and temperature sensation, the dissociated pattern that points toward the front of the spinal cord rather than the whole of it. The imaging that followed produced one of the more distinctive pictures in neuroradiology: two bright, symmetrical dots sitting side by side at the front of the cord, a pattern radiologists call the owl's eye sign.
