What is a Brachial Plexus Injury or BPI?
Defining The Injury
A brachial plexus injury is an injury to one or more of several nerves that make up a network of nerves called the brachial plexus. The injury causes partial or total paralysis in the arm or arms. Conditions frequently associated with this injury are sometimes called Erb's Palsy or Klumpke's Palsy. The brachial plexus lies roughly in the neck and shoulder area. It is comprised of five nerve roots that exit the cervical (neck) and upper thoracic (chest) spinal column and provide control to the arm and hand. There is a brachial plexus on each side of the spinal column.
The brachial plexus nerves are named C-5, C-6, C-7, C-8, and T-1. "C" stands for cervical and "T" stands for thoracic. They are labeled in this way because of the part of the spinal column from which they exit.
Each nerve in the brachial plexus controls its own muscle or muscle groups. (See glossary for the areas that are controlled by each nerve.) For instance C-5 provides control to the deltoid muscle, while C-6 controls the biceps. This, however, is only a general idea of what they control. The brachial plexus actually has several nerves that branch from these roots and control more specific areas. There is probably some overlap of control as well.
This injury can occur from almost any sort of trauma. Police officers and soldiers periodically experience them after bullet wounds. They have also occurred from car accidents and serious falls.
However, brachial plexus injuries are commonly associated with newborn children. Among other instances, a traumatic birth experience in which the physician has to pull the baby out using more force than usual, or in which he or she has to use extraordinary maneuvers to deliver the baby, causes or contributes to the injury. Occasionally, extra force, or extraordinary maneuvers are necessary for some deliveries. As such, some BPI's may be unavoidable. There are, though, correct and incorrect ways to perform the maneuvers.
Some Risks & Precipitating Factors
Frequently, a condition called shoulder dystocia, is the precipitating factor. In a nutshell, shoulder dystocia is a difficult labor resulting from the positioning of the baby's shoulders in the birth canal. When the physician delivers the baby, one or both shoulders get an abnormal amount of stress. This puts pressure on the nerves of the brachial plexus. This pressure eventually causes an avulsion, rupture, or stretch of the nerves. Animated examples of delivery maneuvers for shoulder dystocia can be found at www.evidence.com. Another useful site is www.birthinjury.com .
There are some predisposing factors for shoulder dystocia (and consequently, BPI's). The most important one is probably shoulder dystocia in a previous birth. Previous shoulder dystocia increases the likelihood of a subsequent shoulder dystocia. Another big factor is macrosomia. This term refers to a larger than "normal" child. This does not necessarily mean an abnormal child. Most of the time it just means a big baby.
Diagnosis
Avulsions, ruptures and stretches -- the primary nerve injuries in BPI's -- are often diagnosed using electromyograms (EMG's) or Magnetic Resonance Imaging (MRI's). Though very accurate, these methods generally are not considered 100% reliable. Some experts say that exploratory surgery is the only 100% accurate method of diagnosis. However, Beth Israel Medical Center in New York <www.bethisraelny.org > claims 100% reliability in diagnosing avulsions with their MRI.
With EMG's, a needle is inserted into various areas of the arm. A small electric current is sent through the needle. A machine then reads the muscle contractions and interprets the conduction of the nerves. The procedure is a little invasive and the child probably will experience some pain or discomfort. MRI's are much less invasive. They involve placing the patient inside a long tube. A machine then produces a strong magnetic field around the patient. This magnetic field enables the machine to create very accurate pictures of the inside of the patient.
At one time a procedure called a myelogram was used as a diagnostic tool. In this procedure, an ink is injected into the spinal canal. X-rays are then taken. The ink shows up in the X-ray picture allowing the reader to see where avulsions might be. Because of false positives (and the MRI's general superiority) myelograms have been replaced largely by MRI's.
Prognosis and Treatment
In most cases brachial plexus injuries are self-resolving, often with full recovery. The medical literature generally puts spontaneous recovery at about 80% - 90% of cases. But a good bulk of medical literature tends to suggest that if significant recovery has not occurred by the age of 3 months, then radical treatments like surgery become increasingly considerable. (Return of function to the biceps muscle -- while not a sole determinant -- is often roughly used to predict spontaneous recovery.) Furthermore, surgery tends to be more effective if performed before one year of age. It is said that after one year of age, nerves do not grow as well, which diminishes the likelihood of superior outcomes.
Surgery often consists of harvesting nerves from other parts of the body and directly repairing damaged nerves, or bypassing damaged areas in the brachial plexus. In another procedure, neuroma (scar tissue) is removed from around damaged nerves in an attempt to increase their functionality. These surgeries to the nerves usually are called primary surgeries.
Secondary surgeries usually are done when primary surgeries are inadequate or fail, or when BPI victims are too old for primary surgeries to be considered meaningful. Secondary surgeries often consist of muscle and tendon transfers.
Treatment, both before and after surgery, usually consists of Range of Motion (ROM) exercises coupled with visits to a neurologist. These exercises are usually performed under the supervision of a physical or occupational therapist. Their purpose is to prevent joint contractures. Joint contractures occur when joints have not been moved for long periods of time. This lack of movement causes them to "freeze up". The "freezing up" is called a contracture. Illustrations and descriptions of ROM exercises can be found at erbspalsy.org/rom.html. This is a page in The United Brachial Plexus (UBPN) site listed in the Online Resources page of this site.
All of this is a very basic overview. It is not meant to be exhaustive. The Internet has a great deal of information on this injury. You can start by checking out the online resources page in this site. UBPN is probably your best bet for starters. It's one of the best sites I've discovered and should get you well on your way.
If you have any questions or suggestions for this site, email me at spock@gru.net .