When sleep-related hypermotor epilepsy (SHE) met Charles Darwin and Francis Galton

Sleep-related hypermotor epilepsy (SHE) is characterized by short-lasting seizures patterned by repetitive and stereotyped motor events in the same person. In autosomal dominant SHE, genetic factors play a well-known key role. In The Expression of Emotions in Man and Animals, Charles Darwin quotes a plausible example of SHE illustrated by his cousin Sir Francis Galton: "the gentleman…lay fast asleep on his back in bed, raising his right arm slowly in front of his face, up to his forehead, and then dropping it with a jerk, so that the wrist fell heavily on the bridge of his nose. The trick did not occur every night, but occasionally, and was independent of any ascertained cause. Sometimes it was repeated incessantly for an hour or more." Similar manifestations during sleep occurred also in the patient's son and granddaughter, suggesting an autosomal inheritance without sex relationship. Differential diagnosis with REM behavior disorder and other parasomnias is discussed. To our knowledge, this could be the first description of a stereotyped SHE pattern with genetic transmission.