Scientists use small electric-shock device to activate immune system nerve

Implant found to significantly reduced symptoms of rheumatoid arthritis

Coin-sized gadget provided relief for people for whom no drug had worked

A zap of electricity to the neck could help make arthritic joints less painful.

Scientists have used a small electric-shock generating device to activate a nerve involved in controlling the immune system.

Implanted on the side of the neck, and switched on for as little as a minute a day, it significantly reduced the symptoms of rheumatoid arthritis, which develops when the immune system attacks the joints by mistake.