More than ten years ago my mother died as a result of a sudden, massive stroke. Although she had suffered from breast cancer, she had been doing well until she made an out-of-state visit to my family. During her visit there was no specific symptom or sign that something was wrong, but my mother simply did not look good, appearing less energetic than usual. Several days after returning home she was found unconscious on the floor, having apparently lain that way for most of the previous night. My mother spent the subsequent two weeks in the hospital. Computed tomography showed enormous bilateral cerebral infarcts with tremendous surrounding edema. No etiology could be determined to account for the extensive tissue destruction on both sides of her brain.