Specialties & Conditions Brachial Plexus Palsy
Pediatric Brachial Plexus Palsy
Specialty
What Is Brachial Plexus Palsy (BPP)?
The brachial plexus is a network of nerves which run from the cervical spinal cord (from cervical spine or neck) to the muscles of the upper limb or arm; these nerves transmit signals from the brain that control movement and provide sensation in the shoulder, arm, hand, and fingers.
Brachial plexus palsy refers to an injury to this network of nerves. This injury can occur early in life as seen during birth to later as seen in trauma. The injury can happen when one or more of these nerves gets pinched, stretched, or torn. This may cause the arm to not work as well as it usually does with decreased movement, decreased range of motion, and loss of feeling or sensation.
When brachial plexus palsy is related to birth, it may also be known as:
- Obstetrical brachial plexus palsy or injury
- Neonatal brachial plexus palsy or injury
- Perinatal brachial plexus palsy or injury
- Birth-related brachial plexus lesion or injury
- Congenital brachial plexus palsy or injury
The incidence of newborn brachial plexus injury is estimated to be 0.9 per 1,000 total births. In most cases, only one of the upper limbs is affected. However, in some instances the injury can affect both upper limbs.
What Factors Are Associated with Birth-Related BPP?
Injuries may affect all or only a part of the brachial plexus, so involvement of the upper limb can vary from child to child. Injuries that affect the upper brachial plexus (C5, C6, or C7) affect shoulder and elbow muscles; injuries that affect the lower brachial plexus (C8 and T1) affect forearm and hand muscles.
Some risks factors for the development of brachial plexus birth palsy include:
- Previous child with brachial plexus birth palsy
- Twin or multiple pregnancy
- Transverse lie
- Large gestational size
- Prolonged or difficult labor
- Assisted delivery (e.g., vacuum or forceps)
- Hypotonia (low muscle tone)
It is worth noting, that fifty percent of children affected have no known risk factors.
What Are the Types of BPP?
The nerves that make up the brachial plexus are the fifth, sixth, seventh, eighth cervical nerves and the first thoracic nerve. We label these C5, C6, C7, C8, and T1:
- The C5 and C6 nerve roots form the upper trunk
- The C7 nerve root forms the middle trunk
- The C8 and T1 form the lower trunk
Patterns of Injury
Erb’s Palsy
This is the most common type of injury. Erb's palsy refers to an injury to the upper portions of the brachial plexus resulting in weakness of the shoulder and elbow flexor muscles.
Pan Plexus Palsy
The second most common type of injury. Pan plexus palsy refers to injury to the entire plexus involving the upper, middle, and lower trunks
Klumpke’s Palsy
This is the least common type of injury in children. Klumpke's palsy refers to injury of lower portions of the brachial plexus, affecting muscles lower part of the arm and of the hand.
Severity of Injury
We can also classify the injury in terms of severity of injury to the nerve root.
Neuropraxia
Neuropraxia is where the nerve is stretched but remains intact. In general, all patients with neuropraxia will recover.
Type of Injury
The next form of injury is where the nerve root sheath remains intact but the nerve itself is torn.
Avulsion
Avulsion is the most severe form of injury. This is when the nerve root is pulled off the spinal cord completely. Patients with avulsion will likely not recover.
Neuroma
A neuroma forms as the body attempts to repair itself and regenerate across the injury site.
What Are Signs & Symptoms of BPP?
Some of the signs and symptoms that infants and children present with after sustaining a brachial plexus palsy are loss of feeling, loss of motor control, and limited or no active range of motion.
Children may present with:
- Weakness and decreased range of motion in the shoulder when trying to bring the arm upwards to the side of the body (abduction)
- Weakness and decreased range of motion in bending the elbow (flexion) or inability to fully straighten the elbow (extension)
- Weakness and decreased range of motion in turning the palm of the hand upward (forearm supination)
- Weakness and decreased range of motion extending the wrist and straightening the fingers
- Affected upper limb in the “waiter’s tip position” with the shoulder and upper arm tucked into the body, the elbow straight, and the wrist and fingers bent
How Is BPP Diagnosed?
Brachial plexus birth palsy is diagnosed clinically by a healthcare provider after a thorough medical history and physical examination. Other possible testing may include:
- Radiographs of the collar bone and arm bone – if a fracture is suspected
- Magnetic resonance imaging (MRI) – special imaging study which can look at the nerves as well as the shoulder joint
- EMG and nerve conduction studies – test of the muscle and nerve signals