What is Erb's Palsy?
You may also hear Erbís palsy described as brachial
plexus paralysis, and though it is most common in newborns,
it can occur in adults. Paralysis or limited movement occurs
throughout either of the arms as a result of injuries to one
or more of the nerves that give us feeling and range of
motion in our arms. There are five nerves which can be
affected, resulting in minor to major reduction in sensation
or movement of an arm. All five nerves that can be damaged
and create the condition are part of the brachial plexus, a
network of nerves that are attached to the spine from the
neck to the middle part of the upper spine. If these nerves
are injured in adults, the same symptoms can emerge.
Usually Erbís palsy will result in infants because of
dystocia, difficult presentation and childbirth. A child who
is stuck in the head first position (vertex), may have
nerves damaged due to pulling on the shoulders. Breech birth
can cause the condition too, if the arms are raised above
the head and stretched. A few cases occur if the collarbone
of the newborn is broken.
What causes Erb's Palsy?
Erbís palsy is the result of a nerve injury. All the
armís nerves are connected to a group of nerves near the
neck which is called the brachial plexus. The brachial
plexus nerves are responsible for feeling and motion in the
hand, fingers, and arm.
Erbís palsy can be caused by several things which can
happen during a difficult delivery. Approximately one or two
babies per thousand births will have a brachial nerve
injury. The brachial nerves can be injured if the babyís
neck and head are drawn to the side when the shoulders exit
the birth canal. Pulling excessively on the shoulders as the
baby comes out head first can also lead to a brachial nerve
injury. During a breech birth (feet first), the arms are
usually raised and may be injured from excess pressure.
Improved delivery techniques now prevent many brachial
plexus injuries. Larger than average babies are at greater
risk for this form of injury; larger than average birth
weigh is called macrosomia and is defined as a birth weight
of 8 lb, 13 oz or more. A breech birth (the baby presenting
abnormallyófeet first) also puts the baby at greater risk of
Larger than average babies are especially at risk for a
problem during delivery called shoulder dystocia. In
shoulder dystocia, the infantís head is delivered normally,
but one shoulder becomes stuck under part of the motherís
pelvic bones. This is a difficult situation for doctors to
remedy. The motherís position will be manipulated in an
attempt to free the babyís shoulder and the doctor will also
manipulate the baby within the birth canal. If manipulation
and gentle pressure fail, surgery may be needed.
Shoulder dystocia is dangerous to both the mother and the
baby. A delivery in which shoulder dystocia occurs is most
likely to cause injury to the brachial plexus, resulting in
impaired movement of the injured arm.
Women who are short or who have had gestational diabetes
are at greater risk for the occurrence of shoulder dystocia.
So are women with pelvic abnormalities. Prolonged labor also
increases the risk.
Sometimes shoulder dystocia occurs when it anticipated
that delivery will be normal. The only thing physicians can
do help prevent injury in an unexpected situation is simply
to be always prepared for an emergency during delivery and
to have a medical team familiar with difficult deliveries on
hand during even routine deliveries. Use of forceps or a
vacuum extractor should be avoided if possible during
delivery, because use of these methods increases the risk of
shoulder dystocia. In the case of an extra large baby or a
delivery which is expected to be breech, the physician
should advice the mother and her family of possible problems
and what may be needed to safely deliver the baby.
What are the symptoms of Erb's Palsy?
- Arm paralysis
- Limp arm
- Arm motor control difficulty
- Arm sensation symptoms
- Arm numbness
How is Erb's Palsy Diagnosed?
A physical exam usually shows that the infant is not
moving the upper or lower arm or hand. The affected arm may
flop when the infant is rolled from side to side.
The Moro reflex is absent on the side with the brachial
plexus or nerve injury.
A careful examination of the clavicle or collarbone will
be done to look for a fracture. Sometimes, the infant will
need to have an x-ray of this bone.
SURGERY - Nerve Surgery Treatment
A pediatric neurosurgeon may recommend nerve surgery to
improve the arm functions for a child with Erbís Palsy.
Often this surgery is more effective when done earlier in
the childís life. Some studies have shown that it may not be
successful when done after the child is one year old.
Plastic Surgery Treatment
When nerve surgery is not a viable option, or not
successful, plastic surgery may be considered. During
plastic surgery for treatment of Erbís Palsy, certain
muscles and tendons are transferred to improve function of
the arm. Unlike nerve surgery, plastic surgery for children
with a birth injury is usually not recommended until the
child is older and the muscles are more developed.