Diagnosing Erb’s Palsy

Erb’s palsy or Erb-Duchenne palsy, is a paralysis that affects a baby’s shoulder, arm, and neck. It is an obstetric birth injury that occurs due to a difficult labor, especially if a doctor stretches an infant’s neck too far to one side during delivery. If the child’s brachial plexus nerves in the shoulder are stretched or torn, the affected arm suffers adverse effects that range from a sensation of weakness to  complete paralysis. Most cases of Erb’s palsy can be treated effectively, provided that doctors diagnose the condition as quickly as possible.

What are the Symptoms of Erb’s Palsy?

The symptoms of Erb’s palsy can vary from mild to severe, depending on what type of nerve injury affects the baby’s brachial plexus. There are four basic types of nerve injury that can damage the brachial plexus:

• Neurapraxia, or simple stretching of the nerve
• Neuroma, in which part of the nerve develops scar tissue
• Ruptures, in which the nerve tears when it’s stretched too much
• Avulsion, in which the nerve is completely severed from the spinal cord

These nerve injuries can occur at the same time and exhibit the same symptoms of paralysis and lost sense of touch in the affected arm. The severity of nerve damage determines which treatment options are available and how well the baby recovers from the injury.

Doctors can make an accurate diagnosis based on observations of  the child’s symptoms. The main symptoms of Erb’s palsy include:

• Weakness in the affected arm
• Loss of feeling in the affected arm
• Partial or complete paralysis of the affected arm

Some infants may experience nothing more serious than a sudden onset of  weakness or tenderness in the arm that correspond to the side of the neck where the nerve injury occurred.. Other babies may show more severe symptoms. They may be unable to move the arm as a result of partial or total paralysis due to nerve ruptures or avulsions. Children over the age of two may only seem to favor one arm over the other.

Because the amount of damage determines the severity of Erb’s palsy symptoms, the level of pain your child may experience will vary accordingly. Some children may only feel quick twinges of pain called stingers if the nerve is only stretched. Others may either feel extreme pain or a long-lasting loss of sensation in the affected arm.if scar tissue forms on the nerve or if the nerve has ruptured..

When Do the Symptoms of Erb’s Palsy Arise?

The symptoms of Erb’s palsy may either be noticeable immediately or they may take some time to develop.  One early indication of Erb’s palsy is If your infant isn’t moving one arm. However, you may not be able to tell  that there is any nerve damage until your child has reached the toddler stage of development .Severe effects of Erb’s palsy may slow down or prevent an infant’s developmental milestones such as crawling. On the other hand, your child’s symptoms may be so mild that you don’t notice tenderness or mild pain in the  affected arm until he or she is old enough to talk and let you know that something is wrong.

X-Rays

To determine if an infant has Erb’s palsy or other condition caused by an injury to the brachial plexus, a doctor may order an X-ray examination. X-rays are a form of radiation used in medical imaging, primarily to detect damage to bones or internal organs. Most X-rays can’t produce images of nerve damage, but radiographs are useful to rule out fractured bones or problems with the baby’s shoulder and elbow joints.

Electromyography (EMG)

An electromyography (EMG) is a technique used to estimate and record the electrical activity created by the skeletal muscles. EMGs are useful in gauging the amount of nerve damage suffered by an injury to a baby’s brachial plexus. A pediatrician inserts a needle electrode into an infant’s arm muscles. The electrode measures electrical activity of the muscles as they contract and relax. The infant may feel a sting when the electrode is initial but overall, the rest of the EMG procedure is usually painless.

Nerve Conduction Studies (NCS)

Nerve conduction studies are part of an EMG procedure. They are used to measure how fast a nerve conducts an electrical current that passes through it. An NCS is an effective method to gauge how much nerve damage is present in cases where Erb’s palsy may have occurred.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) scanners use magnetic fields and radio waves to produced sharp, vivid images of a person’s body. MRIs are often used to detect cancers or tumors that affect various nerves, but they can also help doctors determine how much damage was caused by a brachial plexus injury. MRIs are used to see if a nerve has been torn away from an infant’s spinal cord. MRIs can also help detect damage to the affected arm’s arteries in case the limb has to be surgically repaired.

Computerized Tomography (CT) Myelography

Computerized tomography (CT) scans use a combination of computer-processed X-rays and an injection of a contrasting material to take detailed cutaway images of the bones, muscles, and nerves. In a CT myelography, doctors perform a spinal tap to inject contrast material to create an accurate image of a child’s spinal cord and nerve roots. This procedure is usually done in older children and only if an MRI doesn’t give enough information about nerve damage.