Erb’s palsy is a type of brachial plexus injury that affects the nerves and muscles of one arm. Erb’s palsy often occurs when a baby’s neck is stretched to one side during delivery and the nerves are damaged. One to two out of every 1000 live babies born per year sustains injuries resulting in Erb’s palsy. About 92 percent of those affected by the condition make a full recovery, but treatment and therapy may be necessary. Children that do not recover from Erb’s palsy may develop contractures and deformities that impair arm and hand function and alter appearance.
What is Erb’s Palsy?
Erb’s palsy is a type of brachial plexus palsy, with “palsy” meaning weakness and “Erb” being taken from one of the doctors that first diagnosed the condition-Wilhelm Erb. The brachial plexus is a bundle of intertwined nerves that pass through the upper vertebrae, the spinal cord, the neck and the shoulders. Erb’s palsy occurs when this bundle of nerves is damaged due to trauma of some sort. The most common cause of Erb’s palsy is birth complications.
Erb’s Palsy Causes
The stretching of the nerves or trauma to the nerves of the brachial plexus that causes Erb’s palsy is often a result of shoulder dystocia or excessive force being exerted during the process of labor. Pulling on the infant’s shoulders or another part of the infant’s body to speed delivery may also cause brachial plexus nerve injuries. In rare cases the natural force exerted by the uterus may cause Erb’s palsy injuries, but physician assistance is the cause in many cases. Depending upon the circumstances, brachial plexus injuries caused by physician intervention may be considered malpractice.
Erb’s Palsy Risk Factors
Factors which may increase the risk of birth injuries that cause Erb’s palsy may include:
- High birth weight
- Maternal diabetes
- Use of vacuum extractor
- Prolonged pregnancy
- Prolonged labor
- Maternal obesity
- Small mother or birth canal
- Abnormal birth presentation
- Previous delivery of a baby with Erb’s palsy
Types of Erb’s Palsy Injuries
There are four main types of brachial plexus injuries that can cause Erb’s palsy: avulsion, rupture, neuropraxia, and neuroma. Avulsion is a severe type of brachial plexus injury which occurs when the nerves are completely torn away from the spine. Avulsion may cause breathing difficulties in addition to complications with the affected arm. Rupture occurs when nerve cells, blood cells, and connective tissue outside of the spinal cord are damaged. Neuropraxia occurs when the brachial plexus nerves are stretched so that the nerve signals are blocked but no structural damage occurs. Neuroma is caused by the healing process of injured brachial plexus nerves generating scar tissue that blocks nerve signals and interferes with arm function.
Erb’s Palsy Symptoms and Diagnosis
Erb’s palsy is commonly identified by the way that a newborn holds his or her arm. Common Erb’s palsy positions include holding the arm close to the body with the hand bent at an angle and holding the arm against the body with the elbow bent. Physicians may check reflexes and function to diagnose Erb’s palsy. Physicians may also use scan tests such as x-rays and MRIs to determine the extent and severity of injuries.
Erb’s Palsy Treatment and Prognosis
Brachial plexus injuries such as avulsion and ruptures may require surgical intervention followed by physical therapy. Less severe cases of Erb’s palsy often resolve with only daily range of motion and stretching exercises being performed. Most cases of Erb’s palsy are curable and leave no lasting long-term effects. Rare and very severe cases may require breathing assistance and may affect development and life-long arm function.
Erb’s Palsy Prevention
Most cases of Erb’s palsy that occur during childbirth are preventable. Physicians can mitigate the likelihood of Erb’s palsy by identifying risk factors and working to minimize the effect that these risk factors can have on delivery. Ordering timely cesarean sections, properly using tools such as vacuum extractors, and inducing labor before pregnancy is prolonged may help to prevent Erb’s palsy.
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