Erb's Palsy

Also known as brachial plexus paralysis, is the paralysis of the arm caused by injury to the upper group of the arm's main nerves (specifically, spinal roots C5-C7). This almost always occurs during birth. 

The most common cause of Erb's palsy is dystocia, an abnormal or difficult childbirth or labor. For example, it can occur if the infant's head and neck are pulled toward the side at the same time as the shoulders pass through the birth canal. The condition can also be caused by excessive pulling on the shoulders during a head-first, or vertex, delivery. 

The baby’s paralysis can be partial or complete; the damage to each nerve can range from bruising to tearing. The most commonly involved root is C5 (also known as Erb’s point: the union of C5 & C6 roots) as this is mechanically, the furthest point from the force of traction, therefore, the first or most affected. 

Challenges Presented by Erb's Palsy

The most commonly involved nerves are the supra scapular nerve, the musculocutaneous nerve, and the axillary nerve. The injury often leaves babies with stunted growth in the affected arm with everything from the shoulder though to the fingertips smaller than the unaffected arm. This can also leave the baby with impaired muscular, nervous and circulatory development. The lack of muscular development leads to the arm being much weaker than the unaffected one, and less articulate, with many babies unable to lift the arm above shoulder height unaided, as well as leaving many with an elbow contracture. 

The lack of development to the circulatory system can leave the arm with almost no ability to regulate its temperature, which often proves problematic during winter months when it would need to be closely monitored to ensure that the temperature of the arm was not dropping too far below that of the rest of the body. 

The damage to the circulatory system, however, also leaves the arm with another problem: It reduces the healing ability of the skin, so that skin damage takes far longer than usual to heal, and infections in the arm can be quite common if cuts are not sterilized as soon as possible. This will often cause many problems for children since they often injure themselves in the course of their childhoods. 

The nervous damage is often the most problematic of the side effects to Erb's Palsy, but it is also the most varying. There have been cases of babies who have lost complete sensory perception within the arm after procedures whereas they had full sensory perception before. The most common area for a loss of sensory perception (except where the arm faces a total loss) is that between the shoulder and the elbow since the nerves which provide information from that area to the brain are also those first damaged in the initial causative trauma. 

Notably, if the entire arm from the shoulder down is paralyzed, then there is often an associated Horner's Syndrome. Horner’s Syndrome is caused by damage to the sympathetic nervous system. It is also known oculosympathetic palsy. It is characterized by one side of the face include drooping upper eyelid from loss of sympathetic innervation, or slight elevation of the lower lid, or constricted pupil. Another characteristic is the impression that the eye is sunk in and decreased sweating on the affected side of the face. 

In children, Horner's syndrome sometimes leads to a difference in eye color between the two eyes (heterochromia).

Additionally, demonstrable sensory loss in the arm is present and there can be an associated Torticollis. Torticollis is when the baby faces toward his good side and is unable to face forward for any length of time. 

Treatment of Erb's Palsy

Some babies recover on their own; however, some may require surgeries and nerve transplants. 

Neonatal/pediatric neurosurgery is often required for avulsion fracture repair. Lesions may heal over time and function return. Physiotherapeutic care is often required to regain muscle usage.  

Although range of motion is recovered in many children under one year in age, individuals who have not yet healed after this point will rarely gain full function in their arm and may develop arthritis. 

The three most common treatments from Erb's Palsy are: 

1.            Nerve transfers (usually from the opposite leg): 

The nerve transplants are usually performed on babies under the age of 9 months since the fast development of younger babies increases the effectiveness of the procedure. They are not usually carried out on patients older than this because, although small babies nerves can recover to an extent, when the procedure is done on older infants, more harm than good is done and can result in nerve damage in the area where the nerves were taken from. Scarring can vary from faint scars along the lines of the neck to full "T" shapes across the whole shoulder depending on the training of the surgeon and the nature of the transplant. 

2.           Sub Scapularis releases: 

Subscapularis releases, however, are not time limited. Since it is merely cutting a "Z" shape into the subscapularis muscle to provide stretch within the arm, it can be carried out at almost any age and can be carried out repeatedly on the same arm, however this will compromise the integrity on the muscle.  

3.            Latissimus Dorsi Tendon Transfers: 

The Latissimus Dorsi Tendon Transfers involve cutting the Latissimus Dorsi in half horizontally in order to 'pull' part of the muscle around and attach it to the outside of the biceps. This procedure provides external rotation to varying degrees of success. A side effect of this may be increased sensitivity on the part of the biceps where the muscle will now lie since the Latissimus Dorsi has roughly twice the amount of nerve endings per square inch than other muscles.