A 37-year-old, right-handed woman was admitted to the hospital because of vertigo and left-sided weakness. The patient was normal until 3 days before admission however after she suddenly had a sensation of the room spinning, associated with nausea and an unsteady gait. Approximately after 4 hours in the emergency department, her symptoms worsened and numbness and weakness developed suddenly in the left arm.
Subsequently, she had pain in the left thigh and involuntary movements of the left leg. After laboratory examinations her white-cell count was 14,500 per cubic millimeter (reference range, 4500 to 11,000) and the platelet count was normal; the hematocrit was 32.4% (reference range, 36.0 to 46.0), the hemoglobin level 10.6 g per deciliter (reference range, 12.0 to 16.0), the mean corpuscular volume 65 fl (reference range, 80 to 100), the mean corpuscular hemoglobin 21.3 pg per red…
