What is Erb's Palsy?
Erb's Palsy is the name given to a type of brachial plexus palsy occurring at birth. To understand Erb's Palsy, it is important to understand what brachial plexus is and what is its function. Anatomically speaking, the brachial plexus is a network of nerves near the neck through which all the nerves of the arms arise meaning that the nerves arising from the brachial plexus provide sensation, and movement to the arms, shoulder, and hands. The word Palsy means weakness, meaning that brachial plexus palsy or Erb's Palsy is weakness of the brachial plexus and thus there is resultant weakness of the arms and hands and there is impairment of motion of the hands.
Erb's Palsy is found in about 2 of every 1000 children born. The main cause of this condition is the neck of the infant getting overly stretched during a complex or difficult delivery. Erb's Palsy is not a permanent condition and majority of children with this condition recover completely with time and therapy.
What are the Causes of Erb's Palsy?
As stated, above, Erb's Palsy is normally caused due to an injury to the neck resulting in an injury to the brachial plexus causing Erb's Palsy. This injury may be caused due to over stretching of the neck during a complex and difficult delivery. Another reason for Erb's Palsy may be the infant's neck, head, and shoulders are dragged to one side at the time of delivery, especially when the shoulders are coming out causing an injury to the brachial plexus. Breech presentation deliveries also put the infant at risk for having brachial plexus injury resulting in Erb's Palsy. Another risk factor for developing Erb's Palsy is children who are born larger than normal.
What are the Symptoms of Erb's Palsy?
The main symptoms of Erb's Palsy are:
- Weakness in one arm or both
- Loss of sensation in the arms
- Partial or complete paralysis of the arms.
How is Erb's Palsy Diagnosed?
A diagnosis of Erb's Palsy is normally made if a brachial plexus injury is identified and the infant exhibits symptoms of weakness and lack of movement of the arms or hands during physical examination.
An injury to the brachial plexus may be identified by radiological studies in the form of x-rays, CT scan, or MRI scan of the neck around the brachial plexus region which will clearly show an injury to the brachial plexus thus confirming the diagnosis of Erb's Palsy. The radiological studies will also confirm whether there has been any damage to the joints, bones or other structures in and around the neck and brachial plexus area.
The doctor may also do an EMG and nerve conduction studies to check whether there are any abnormalities in the nerves in the arms to confirm the diagnosis of Erb's Palsy.
How is Erb's Palsy Treated?
In majority of cases of Erb's Palsy, the infant recovers completely on their own in some weeks or months and hence observation is the first line of treatment for this condition. During this phase of treatment for Erb's Palsy, the child will be given extensive physical therapy to improve the strength and motion of the arms. The child will need to have regular followups to check on the status of the nerves as the nerves tend to heal very slowly and hence it may take up to a year or two for complete recovery from Erb's Palsy through a conservative approach. It is important to note here that the parents need to play an active role here when it comes to physical therapy. The doctor may refer the parents to a physical therapist where the child will undergo extensive exercises for range of motion and strengthening so that the arms and hands do not become permanently stiff due to Erb's Palsy.
Erb's Palsy may also be treated surgically in cases there is no change in the condition of the child even after six months of age. The surgery done to correct the nerves and improve the chances of a good outcome is:
Nerve Grafting: Depending on the nerve injury, the nerve may be repaired by taking a nerve graft from another nerve of the child.
Nerve Transfer: In this procedure, an entire nerve is taken from somewhere else in the body and is transferred to the affected nerve so as to restore function of the arm.
Postsurgery, aggressive physical therapy will be required to restore movement of the arm and strengthen the area. Since nerves recover very slowly it may take up to a year for the child to regain full function of the arm.
What is the Prognosis of Erb's Palsy?
Normally if the injury is mild and nerve damage is minimal then the child with Erb's Palsy may recover to full functioning of the arm within six to eight weeks of delivery. In case if there is a damage to the nerves then it may take several months or even up to a year despite aggressive physical therapy and other modes of treatment to regain full function of the arm as the nerve heals very slowly and takes about a year for the nerve to be completely healed following Erb's Palsy.