What is Erb’s Palsy?
Erb’s palsy is short for Erb-Duchenne palsy. It is caused by injury to the brachial plexus nerve which runs from the shoulder to the upper arm. It can occur as a “partial” palsy which may resolve in some cases, or a “complete” palsy which indicates the nerve will no longer function. Most cases of Erb’s palsy are a result of a birth injury known as shoulder dystocia.
Shoulder dystocia occurs when there is excessive pulling on the head or shoulders during a normal (head-first) delivery or by pressure on arms which are raised during a breech (feet-first) delivery. Though less common, birth-related Erb’s palsy can also be a result of clavicle fracture which occurs during birth. Older children or adults may also develop Erb’s palsy as a result of injury to the neck or shoulder.
How is Erb’s palsy different from Klumpke’s palsy?
Erb’s palsy and Klumpke’s palsy are similar, often caused by the same type of injury which damages the brachial plexus nerve. The main differences are the area of the brachial nerve which is damaged and the area in which symptoms occur.
Erb’s palsy affects the upper brachial nerve at the C-5 and C-6 vertebrae and causes symptoms that affect the upper arm or the entire arm. Klumpke’s palsy affects the lower brachial nerve at the C-7 and T-1 vertebrae and has symptoms which occur mainly in the forearm or hand.
What causes Erb’s palsy?
Erb’s palsy occurs in 1.6 to 2.9 of 1000 live births. It occurs when the brachial plexus is stretched, damaged or severed during birth. It can occur during a normal cephalic birth (head-first) or during a breech birth (feet-first), usually in one of the following ways:
- The head and neck are pulled to the side during a normal head-first delivery
- The shoulders are pulled inappropriately during a normal head-first delivery
- The baby is delivered in a breech position with the arms raised over the head
Larger babies are at greater risk of birth injury resulting in Erb’s palsy. Breech deliveries and those resulting in prolonged or difficult delivery may also increase the risk. In cases where it is clear that a difficult delivery will occur or when the patient is high-risk, a cesarean section can help to reduce the chance of birth injury.
Types of Erb’s palsy
Though Erb’s palsy is generally described as an injury to the brachial complex nerve, it can be categorized into four types. The four types are defined based on the type and severity of injury and methods or the possibility of treatment.
- Neurapraxia – the most common type of Erb’s palsy which occurs when nerve tissue is stretched but not torn or ruptured. In many cases, neurapraxia will heal on its own over a period of months.
- Neuroma – occurs when stretched nerve injury causes scar tissue formation. Scar tissue may prevent complete recovery and some permanent disability may remain.
- Rupture – a rupture occurs when a nerve is torn. A ruptured nerve will not generally heal without surgery and disability may be permanent.
- Avulsion – the most severe type of Erb’s palsy occurs when the brachial nerve is torn from the spinal column. In some cases, a nerve graft may help to restore function but disability will likely be permanent.
Symptoms of Erb’s palsy
Signs of Erb’s palsy begin right away and are usually obvious. Common Erb’s palsy symptoms include:
- Lack of movement in one hand
- Lack of movement in lower arm on one side
- Lack of movement in the entire arm on one side
- Limpness in one arm
- One arm held bent against the body
- No feeling in arm or hand on one side
- Weakness in one arm with a weakened grip
If symptoms of Erb’s palsy appear, the pediatrician should perform a physical exam and will likely order primary imaging (X-ray) studies. Additional tests may include electromyogram (EMG) testing to test the function of nerves and muscle fibers, along with additional imaging tests including MRI and/or CT scan to identify damage to associated nerves.
Erb’s palsy treatment
In many cases, there are no treatments for Erb’s palsy and symptoms will resolve with time. Doctors may recommend immobilization and rest of the affected arm, followed by a period of physical therapy treatments which may improve mobility, the range of motion and prevent the development of stiffness.
In cases of avulsion, where the nerve is ruptured, surgery may be performed to repair nerve tissue. Surgery may include a nerve graft where donor nerve tissue is spliced onto a damaged nerve or may involve a nerve transplant with a replacement from another area of the body.
Erb’s palsy prognosis
If treatment and recovery begin within four weeks of birth, up to 96% of Erb’s palsy may be resolved during the first year. After that time, the first-year recovery drops to 80% and the longer it takes to diagnose and begin treating Erb’s palsy, the lower the chance for recovery.
Treatment of Erb’s palsy is costly and some disability may be permanent. In some cases, the child’s arm and hand will not grow at the same rate and may be smaller than normal or stunted. Children who suffer an avoidable birth injury like Erb’s palsy may face lifelong problems.
Aside from the physical difficulties of a non or partially-functioning arm or hand, children may face emotional and social challenges such as issues with self-esteem. Children with Erb’s palsy and their parents or caretakers may benefit from supportive psychologist intervention.
When Erb’s palsy develops as a result of an avoidable birth injury, compensation for costly treatment and other expenses may be available.