ectospasm

A ghostly convulsion that is seemingly random in nature, but so intense as to make you wonder whether or not the holy spirit (or in some cases unholy spirit) has in fact come down upon you and is shaking you to your very bones. Signs of ectospasm include trembling with such ferocity that you roll out of bed and hit thine face upon the floor, sudden jerks of the steering wheel while driving that bring you into close proximity of pedestrians (although if anyone asks, you don't know where the red blotches on your car came from), and finally the unconscious performance of midair back flips over pews, or cartwheels down corridors, runways and halls.