Infection with the Lyme bacteria can cause this sort of internal vibration - a type of paresthesia (peripheral nerve sensation). When it's mild, you may first notice it at night when your body is quiet and still.
The supporting cast features James Caan as the young gambler, Charlene Holt, Ed Asner, Paul Fix, Arthur Hunnicutt, Michele Carey, and Christopher George. El Dorado was filmed on location in Tucson, Arizona and Kanab, Utah, and was shot in Technicolor. The paintings in the credits are by Olaf Wieghorst, who plays Swede Larsen in the film. The musical score was composed by Nelson Riddle.
El Dorado, on its original site south of the present El Dorado, was first the county seat of Hunter county and later, upon its organization, of Irving county. The county, as it were, having slipped from under it, the location of the town remaining the same At this time Butler county extended only so far south as the fifth standard parallel. Chelsea was named as the county seat of Butler county by common consent of the settlers. This was upon the organization of the county in 1859, Chelsea remaining the county seat until 1864, after the county had been changed to its present boundaries. On May 21, 1864, an election was held, and El Dorado was selected as the county seat - (this was the old town on the Clarence King farm).