Klumpke paralysis is a rare type of birth injury to the nerves around a newborn’s shoulder, known as the brachial plexus. Most types of brachial plexus injuries affect the shoulder and upper arm. Klumpke paralysis affects the movement of the lower arm and hand. Signs and symptoms include weakness and loss of movement of the lower arm and hand. Some babies experience drooping of the eyelid on the opposite side of the face as well. This symptom may also be referred to as Horner syndrome.

Klumpke paralysis is caused by an injury to the nerves of the brachial plexus that which may result during birth due to a a difficult delivery. This injury can cause a stretch injury (neuropraxia), scarring, or tearing of the brachial plexus nerves. Tearing is called an "avulsion” when the tear is at the spine, and “rupture” when it is not. Diagnosis of Klumpke paralysis is made at birth by physical examination. Sometimes x-rays and other tests are done to determine the extent of the nerve damage. Most infants with Klumpke paralysis have the more mild form of injury (neuropraxia) and often recover within 6 months. Some infants will require surgery. Rarely, infants with Klumpke paralysis will have some permanent damage.

• Surgery on the nerves (e.g., nerve grafts and neuroma excision)
• Tendon transfers to help the muscles that are affected by nerve damage work better