Erb's Palsy also known as Brachial Plexus Paralysis is a condition which mainly due to birth trauma, can affect 1 or all of the 5 primary nerves that supply the movement and feeling to an arm. Each baby's injury is individual. The paralysis can be partial or complete; the damage to each nerve can range from bruising to tearing. Some babies recover on their own however some may require specialist intervention.
Early Intervention is crucial in order to ascertain the full extent of damage caused. There are tests, which can be carried out that show which nerve/s are damaged. Treatment in the first year of life can have a significant impact on recovery. However, if there is no progress or you are worried, you might want to ask your doctor or paediatrician to refer your child to a specialist within the field of Erb's Palsy.
The brachial plexus is made up from five large nerves which come out of the spinal cord between the bones in the neck (the vertebrae) and give movement and feeling to the arm These nerves are represented by the symbols C5, C6, C7, C8 and T1 Shortly after coming out of the neck, the nerves come together and then divide among the muscles and tissues of the arm. The brachial plexus runs from the neck and passes under the collarbone to become the major nerves of the arm at about the level of the armpit.
Nerves are cord like structures of tissue from a collection of nerve fibres. A single nerve may contain thousands of fibres, a bit like a telephone cable. In the arm, these fibres carry electrical messages both ways between the brain, muscles and tissues. For a muscle to work (contract) a message must travel from the brain along a nerve that goes directly to the muscle. When nerve fibres are injured, the muscles that the nerve controls may be weakened, even though the injury is not in the muscle itself.Nerves outside the spinal cord (peripheral nerves) can repair themselves. Damaged nerve fibres are able to regrow at a rate of about 1mm a day or 1 inch a month. It may take many months for regrowing fibres to reach the muscles in the lower arm. If an entire nerve has been damaged or broken, it will not grow back to the muscle.
Many factors affect how severe the injury is. The first is the number of nerves that have been affected. Of the five nerves of the brachial plexus the first two, (C5 C6) are most often involved. A classic sign of this is an elbow which does not bend and the hand being held in a 'waiters tip' (turning backwards) position.Sometimes all the nerves may be affected, if this occurs, weakness or paralysis will affect the entire arm and hand. Signs of this may also include a limp hand and there may be an associated Horners syndrome. This is when the eyelid droops and the pupil in the eye may be smaller. The baby may also have an associated Torticollis. Torticollis is where the baby faces away from their affected arm and is unable to face forward for any length of time. Your baby may also suffer from sensory loss in the arm and hand.
The second is how badly the nerve has been damaged. If the fibres have only been mildly stretched, your child should recover use of the muscle quite quickly. The more fibres that are stretched or pulled apart, the weaker the muscle will be and the longer it will take to start working properly again. A nerve that has been severely damaged but still remains connected may heal, but scar tissue may form at the site of injury. This scar tissue may stop the electrical messages so they can't work getting to the muscles. A nerve that is completely pulled apart cannot repair itself, so the muscles it controls are paralysed. Sometimes it is possible to have an operation to mend the nerve and restore some function to the muscle, if this is necessary, the child is likely to be left with some residual weakness in the arm. In rare cases the nerve may be torn away from the spinal column itself – this is called an AVULSION in these cases it is imperative to consult a specialist in Brachial Plexus Injuries as soon as possible to discuss a treatment plan.