Earphones and headphones have for the first time been shown to damage the coating of nerve cells, leading to temporary deafness.
Surgeons at Washington University School of Medicine in St. Louis have re-routed nerves in the upper arm to restore some hand function in a quadriplegic patient.
British and German engineers have created computer-generated implants that allow damaged nerves to regrow.
Damaging a patient's nerves during surgery can cause agony - and even paralysis. But nerves are rather hard to see.