Brachial Plexus Australia - This site aims to be a hub of information, resources and support for people in Australia with Brachial Plexus Injuries (Erb's Palsy). Contributions and requests are welcome!
Overview of Brachial Plexus Injuries
Written by Dr Richard Lawson FRACS - Hand Surgeon
What is the brachial plexus?
The brachial plexus is a group of very important nerves that runs from the neck into the shoulder and arm, controlling all the movements and sensation of the arm. The nerves are large, around 5mm in diameter, and branch and intermingle in a complex fashion. The nerves start at the spinal cord, pass out between the vertebrae in the neck, run across the space from the neck to beneath the collar bone, and then run into the arm.
As the nerve branches leave the spinal cord they form 5 major bundles, called roots. These are labelled the C5, C6, C7, C8 and T1 nerve roots; the C refers to cervical and the T to thoracic, thus the C5 nerve root is the 5th cervical nerve root.
How is the brachial plexus damaged?
The two main groups of patients with brachial plexus injuries are babies and young adults (usually males). In babies, the plexus can be torn if the baby’s head and shoulder are pulled in different directions during delivery; this typically happens in big babies and difficult deliveries.
The other major group is of young adults exposed to major trauma, such as falls from motorbikes. In these patients the head and shoulder are usually pulled in opposite directions as the helmet hits the ground. Huge forces are developed, and these can lead to extensive damage to the plexus. The force of the accident can also lead to injuries to other structures in the region, such as the neck, collar bone and shoulder.
The prognosis for recovery is best when there is less trauma; thus, the vast majority of babies with an injured brachial plexus improve, while spontaneous improvement is less likely in adults with traumatic injuries.
In the most common pattern of injury the upper nerve roots are damaged (that is the C5 and C6 nerve roots), and this kind of injury is particularly common in babies, most of whom go on to recover. Patients with this kind of injury have difficulty lifting the arm to the side, and flexing the elbow up, but tend to have excellent hand function.
The less common and more severe pattern of injury involves damage to all the branches of the brachial plexus, and in the most severe cases can lead to a flail arm which dangles by the patient’s side, with no function. This is usually seen in high speed motor cycle injuries.