For six months, a 58-year-old woman in China got out of bed in the predawn hours and started doing chores. She folded blankets, walked around, and wiped down tables. On other nights she shouted, repeatedly touched her head or thrashed so hard that she often fell out of bed.
Her family could not wake her during the episodes, and she had no memory of them afterward. The behavior looked like a sleep disorder or a form of epilepsy. Doctors eventually traced it to a much less likely source: dangerously low overnight blood sugar linked to a rare, benign growth in her pancreas.
