Deep-Brain Stimulation — Entering the Era of Human Neural-Network Modulation

Scribonius Largus, the court physician for the Roman emperor Claudius, used an electrical torpedo fish in 50 A.D. to treat headaches and gout. More than 1000 years elapsed before the idea of therapeutic brain stimulation was rekindled. In 1786, Luigi Galvani demonstrated that he could conduct electricity through the nerves in a frog's leg. Later, Alessandro Volta conducted electrical current through wires and built crude but effective battery sources. Yet none of these experimenters could have predicted the usefulness of their technology in treating human disease by applying an electrical current within the human brain...

 http://www.nejm.org/doi/full/10.1056/NEJMp1408779

NEJM 2014