Polyneuropathy is a disease of the peripheral nervous system in which several nerves are affected at the same time. The damage to the nerves disrupts the transmission of information between the brain, spinal cord and the rest of the body. The disease leads to dysfunction in the peripheral nerves that supply the extremities, muscles, skin and internal organs. The most common symptoms include tingling, numbness, pain, unsteady gait and muscle atrophy, particularly in the feet and hands.

There are many possible causes of polyneuropathies, including diabetes mellitus, alcohol consumption, certain medications, infections, autoimmune diseases, genetic factors and toxin exposure. Despite all diagnostic advances, the cause remains unclear in one in five cases.