Brachial plexus injuries affect the nerve network that provides feeling and muscle
control in the shoulder, arm, forearm, hand, and fingers.
In newborns, these injuries can happen if:
the birth is complicated by a breech (bottom-first) delivery
the mother has a very long labor
the baby's shoulders are too wide to fit through the birth canal
There are different kinds of brachial plexus (BRAY-kee-ul PLEK-sis) injuries. Depending
on where the nerve damage is, the injuries sometimes are called neonatal brachial
plexus palsy, brachial plexus birth palsy, or Erb's
What Happens in a Brachial Plexus Injury?
During childbirth, a brachial plexus injury can happen if the baby's neck is stretched
to one side.
The brachial plexus nerve network begins with nerve roots at the spinal
cord in the neck and reaches to the armpit. Nerves branch out from there and continue
down the arm to the forearm, hand, and fingers.
When a strong force increases the angle between the neck and shoulders, the brachial
plexus nerves might stretch or tear. The injury may also pull the nerve roots of the
brachial plexus from the spinal cord. Damaged nerves carry sensation poorly and make
muscle movements weak.
What Are the Signs & Symptoms of a Brachial Plexus Injury?
Signs of a brachial plexus injury usually include:
full or partial lack of movement
a weakened grip
an odd position (the arm may bend toward the body or hang limp)
How Is a Brachial Plexus Injury Diagnosed?
Neonatal brachial plexus injuries are a common type of birth injury (2 to 3 for
every 1,000 births). Yet, identifying them in newborns can be hard. Doctors will check
the affected arm for paralysis, numbness, position, and grip strength. They also will
check a baby's Moro reflex (startle response). This is when a baby throws out the
arms and legs, then curls them in when startled.
A specialist who treats infants with these injuries usually oversees the tests
and treatments. The specialist might order:
nerve conduction study (NCS) and electromyogram (EMG) to test nerve and muscle
If pain, weakness, or numbness continue, surgery often can help. Surgical treatments
Nerve grafts: A nerve from another area of the body, such as
a rib or the back of the foot, is used to patch an injured brachial nerve. A nerve
framework from an organ donor or a manufactured nerve growth guide also can encourage
Nerve transfer: A healthy nerve in the area or some of its fibers
restores injured nerve connections.
Muscle transfer: A muscle, usually taken from the child's thigh,
replaces a paralyzed muscle in the arm.
Tendon transfer: Tendons are moved from working muscles near
the shoulder to increase arm movement and control.
After surgery, it may take 8 months or longer for new nerve function to show. Improvements
in strength, range of motion, and control may continue for up to 18 months or more
It's important to diagnose and treat a brachial plexus injury as quickly as possible.
Early treatment offers the best chance for a baby's fullest recovery.