Lord Byron's physician: John William Polidori on somnambulism.

John William Polidori (1795-1821) was the Edinburgh-trained physician hired by Lord Byron to accompany him to Switzerland, where he participated in the story-telling event proposed by Byron that led, with Polidori's help, to Mary Shelley's Frankenstein. Although those interested in English literature might also remember Polidori as the author of The Vampyre, one of the first extended works of fiction about vampires, his earlier interest in somnambulism and trance states is only beginning to be appreciated. Even more than students of Romantic literature, historians of science and medicine seem little aware of what Polidori had written about oneirodynia, a synonym for somnambulism, and how his thoughts from 1815 about such activities reflected the changing medical zeitgeist at this time. This chapter examines Polidori's medical thesis in a neuroscience context and compares what he wrote to the writings of several other physicians who were fascinated by nocturnal wanderings, their causes, their manifestations, and their possible treatments.