Scrambler therapy for chronic pain

Records from Ancient Egyptians— and later, Greek and Roman civilizations — suggest that people with persistent pain were made to stand in pools of water charged by eels. Today, a new approach to that ancient idea — without the electrical fish — is showing some promise in treating chronic pain.

Called scrambler therapy, it involves electrical signals sent along nerve pathways to the brain. It aims to retrain the brain to perceive an area of pain as not painful. The treatment was approved by the Food and Drug Administration in 2009.

Pain is caused by a harmful or aggravating stimulus from outside or inside the body. Nerve cells transmit sensations through various receptors along nerve pathways to the spinal cord. The signal then passes to the brain, which registers the painful sensation. Usually, after the initial pain, the nerves are in a state of excitement from the pain. The nerves eventually calm down, and the pain isn’t felt anymore.