Via The New York Times:
The riffs are based in an offshoot blues language that descends directly from Black Sabbath. Black Sabbath recorded a song in 1972 called “St. Vitus Dance.” St. Vitus’s Dance is a neurological disorder, also known as Sydenham Chorea, associated with an uncontrollable jerking of the feet, hands and face. Saint Vitus was a fourth-century Sicilian martyr who became the patron saint of entertainers and epileptics.