How Often Does Erb’s Palsy Occur?
Approximately 0.9 to 2.6 cases of Erb’s palsy occur for every 1,000 live births.
Erb’s palsy is the most common form of brachial plexus palsy, but there are several different types of the condition, each occurring at a different prevalence rate.
Causes of Erb’s Palsy
- Pressure on raised arms during a breech delivery: When a doctor pulls on the infant’s feet during a breech (feet-first) delivery, this puts significant pressure on the child’s raised arms. This pressure can lead to damage in the nerves or muscles associated with the shoulder, arm hands and fingers.
- Stretching of the shoulders during a head-first delivery: During a head-first delivery, some doctors will pull on the child’s shoulders to quicken the delivery process. This pressure on the shoulders can lead to damage of local nerves.
- Pulling the infant’s head and neck as the shoulders pass through the birth canal: Doctors may pull on the head and neck of an infant during the delivery process. In particular, they may pull the infant’s head and neck toward the side to ease delivery as the shoulders come through the birth canal. This can lead to injury and muscle weakness or paralysis of the shoulder.
Types of Brachial Plexus Palsy
- Erb’s Palsy: Erb’s palsy accounts for 45% to 50% of all brachial plexus palsy cases. It is associated with damage to the nerves at the C5 to C6 sections of the spine.
- Extended Erb’s Palsy: This version of brachial plexus palsy is associated with an injury at the C7 section of the spine. It accounts for about 20% of brachial plexus palsy cases.
- Total Plexus Involvement: Total plexus involvement accounts for 35% of brachial plexus palsy cases. It is the second most common form of the condition and is sometimes called total brachial plexus paralysis. All muscles in the shoulder, arm, hand and fingers are affected in infants with this condition. Total plexus involvement generally includes an injury to nerves at the C5 to T1 sections of the spine.
- Klumpke Palsy: This is the rarest form of brachial plexus palsy. It accounts for less than 1% of all cases. It involves damage to the C8 to T1 sections of the spine. Generally, only muscles in the hand and forearm are affected in these cases.
Who Is at Risk of Developing Erb’s Palsy?
There are certain demographics who have higher concentrations of Erb’s palsy cases. Additionally, there are several factors which are associated with higher Erb’s palsy risk. Learning who is at risk of developing Erb’s palsy means understanding these factors and the challenges that face these demographics.
Erb’s Palsy Risk Factors
- Forceps delivery or vacuum extraction: Children delivered using forceps or vacuum extraction have a higher risk of Erb’s palsy. The excessive force applied to the nerves in the neck can directly lead to weakness in the shoulder, arm, hand and fingers.
- Shoulder dystocia: Shoulder dystocia has been called the most common risk factor for Erb’s palsy. It occurs when the size of the infant’s body and shoulders does not match the maternal pelvic diameter.
- Above average birth weight: Children with an above average birth weight have a higher risk of developing Erb’s palsy. This may be because heavier children have a difficult time in the birthing process as additional pressure is put on nerves in the neck and shoulder.
- Gestational diabetes: Gestational diabetes can affect mothers later in their pregnancies. The spike in blood sugar can damage the nerves of the fetus and lead to Erb’s palsy.
Common Demographics in Erb’s Palsy Cases
Certain demographics have higher rates of Erb’s palsy diagnoses. Mothers from low-income communities with poor health insurance are at the highest risk.
These mothers may have limited access to prenatal care and may not be able to detect significant risk factors such as gestational diabetes. These mothers are also at higher risk of delivering in crowded hospitals with poorly trained medical staff who may injure the infant during delivery.
Erb’s Palsy Treatment Success Rates
Erb’s palsy is not considered a permanent condition. It is estimated that over 80% of children suffering from Erb’s palsy will make a full recovery.
If treatment begins within the first four weeks of birth, the rate of recovery increases to nearly 100%.
Therefore, children who receive their Erb’s palsy diagnosis shortly after birth stand the best chance of making a complete recovery.
After the injury is identified and diagnosed, medical professionals typically conduct radiographic studies of the chest, shoulder and arm along with a neurological evaluation to determine the extent of the injury. In virtually all cases, the first course of action is physiotherapy and routine evaluation. This leads to significant improvement in nearly 95% of cases.
In the 5% of cases where physiotherapy leads to no significant improvement, surgical options are assessed. Surgery may include nerve grafts, muscle or nerve transfers or neurolysis. After surgery, the child will again continue physiotherapy.
About half of the post-surgical cases will lead to a good recovery. However, the half that has no improvement likely has a permanent disability.
Importance of Prevention and Early Intervention
Erb’s palsy can be a shocking diagnosis for parents. A significant percentage of Erb’s palsy cases could have been prevented with improved prenatal care and delivery methods. Delivery methods such as vacuum extraction and forceps delivery are associated with higher risk of Erb’s palsy in children.
Prevention is important because although the majority of children diagnosed with Erb’s palsy will recover, at least 5% will not, instead suffering a permanent disability.
Children who have their Erb’s palsy diagnosed shortly after birth and begin physiotherapy soon afterward stand the best chance at making a complete recovery.