The brachial plexus is a group of nerve cables that connect the spinal cord in the neck to the nerves that supply the arm. The nerve roots that arise from C5 to C8 and T1 segments of the spinal cord join to form the brachial plexus that branch out to form the various nerves that supply the upper limb. Injury to this important group of nerve cables can occur during difficult delivery, when the brachial plexus is stretched or torn.

When delivery is difficult, as in a large baby, or breech presentation, or prolonged labor, the neck is stretched, and this can lead to a neuropraxia (nerve stretch) which is temporary or an axonotmesis or neurometsis (disruption or tear) which may be irreversible.

Most often, the upper part of the brachial plexus is involved (C5 and 6) and is called Erb’s palsy. Less often, the lower part of the brachial plexus is involved (C7, T1) and is called Klumpke"s paralysis. In some situations, the whole brachial plexus is involved.

It is usually quite obvious. Typically, the newborn lies with the involved arm by its side, with the elbow extended, and does not move it.

Injuries associated with brachial plexus palsy include the neck, clavicle, shoulder and arm. If clinical examination warrants it, X-rays are important to rule out any cervial spine injuries, fracture clavicle or humerus, or dislocation of the shoulder.

The incidence of obstetric brachial plexus injuries is quite low, around 1 to 2 per 1000 live-births. It is often associated with difficult labor, and though preventable, cannot be totally eliminated. In a situation where time is of the essence to prevent fetal anoxia, brachial plexus injuries will continue to occur even in the best of hands.

Your doctor will do X-rays to rule out associated injuries of the neck, clavicle or humerus.

Most brachial plexus injuries are of the Erb’s type, and usually mild. These are expected to recover over 3 to 4 months. The more severe injuries may take 18 to 24 months to recover. It is important while waiting for recovery, that the child be placed on physical therapy. Gentle range of motion exercises and electrical stimulation of muscles need to be performed regularly to keep the joints of the arm supple, and prevent atrophy.

By the age of 3 months, if there is no improvement of movement of the arm, and it remains flail, a myelogram or MRI may be ordered to evaluate the status of the brachial plexus. If the myelogram or MRI shows a tear of the brachial plexus, consideration may be given to perform a repair and nerve graft. This is recently popularized in Europe, and results appear to be promising. Some centers in the U.S are also getting encouraging results with this difficult problem.*

As mentioned before, most mild cases of brachial plexus injuries recover in 3 to 4 months. The more severe cases improve slowly over 18 to 214 months. By 2 years of age, any recovery that will occur should have occurred, and no further improvement is expected.

Surgical correction for permanent disability or deformity can be performed in the school-aged child where necessary. A common deformity is an adduction-internal rotation position of the arm, which can be corrected by a rotation osteotomy of the humerus. In cases where shoulder abduction is weak because of deltoid paralysis, a latissimus dorsi transfer can be helpful.

*for information about the Texas experience