Brachial neuritis is a form of peripheral neuropathy that affects the nerves going to the chest, shoulder, arm, and hand. Peripheral neuropathy is a condition that causes pain or loss of function in the nerves that carry signals to and from the brain and spinal cord (the central nervous system) to other parts of the body. Brachial neuritis is fairly rare.
It's also referred to as brachial neuropathy or a brachial plexus injury. When the condition is acute, the damage to the brachial nerves comes on suddenly. It isn't related to any other injury or health condition. This is also called Parsonage-Turner syndrome or neuralgic amyotrophy.
Brachial neuritis affects mainly the lower nerves of the brachial plexus, in the arm and hand. The brachial plexus is a bundle of nerves that travels from the spinal cord to the chest, shoulder, arms, and hands. This condition usually affects just one side of the body. But it also can involve other nerves and other parts of the body.