Brachial Plexus Injury
Definition |
Causes |
Types |
Risk factors |
Related diagnoses |
Surgical management |
Treatment |
Life-long considerations |
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What is the brachial plexus?
The brachial plexus (BRAY-key-el PLEK-sis) is a network of nerves that provides movement and feeling to the shoulder, arm and hand. The nerves supporting the arm exit the spinal column high in the neck; those that support the hand and fingers exit lower in the neck.
This nerve complex is composed of four cervical nerve roots (C5-C8) and the first thoracic nerve root (T1). These roots combine to form three trunks. C5-C6 form the upper trunk, C7 continues as the middle trunk and C8-T1 form the lower trunk.
Each trunk splits into a division. Half the divisions globally supply flexor muscles (that lift and bend the arm). The others supply the extensor muscles (that straighten the arm and bring it down).
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What causes a brachial plexus injury?
The cause of a birth brachial plexus injury is usually due to a stretching injury involving the child's brachial plexus during vaginal delivery, but this is not always the case as such injuries have also been reported following Caesarean sections. This excessive stretch results in incomplete sensory and / or motor function of the injured nerve. A brachial plexus injury may occur in up to three of every 1,000 live births. Traumatic Brachial Plexus injuries may occur due to motor vehicle acidents, bike accidents, gunshot wounds, sports, etc. Nerve injuries vary in severity from a mild stretch to the nerve root tearing away from the spinal cord.
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What are the types of brachial plexus injuries?
- Avulsion
- The nerve is torn away from its attachment at the spinal cord; the most severe type. An eyelid droop suggests a very severe avulsion of the lower brachial plexus (Horner's Syndrome).
- Rupture
- The nerve is torn, but not at the spinal cord attachment.
- Neuroma
- Scar tissue has grown around the injury site, putting pressure on the injured nerve and preventing the nerve from sending signals to the muscles.
- Neurapraxia (Ner-ra-PRAK-see-ah)
- The nerve has been stretched and damaged but not torn.
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Risk factors of brachial plexus injuries
- Shoulder dystocia (the baby's shoulder being restricted on the mother's pelvis)
- Maternal diabetes
- Large gestational size
- Difficult delivery needing external assistance
- Prolonged labor
- Breech presentation at birth
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Brachial plexus injury presentation at birth
- Normal presentation 94-97%
- Breech presentation 1-2%
- Cesarean deliveries 1%
Diagnoses related to brachial plexus injuries
Erb's Palsy
- C5, C6 and sometimes C7 nerves are involved
- Often presents with arm straight and wrist fully bent (waiter's tip)
- May have good hand function but not full movement of the arm
- May have instability of the shoulder joint
- Often present with weak biceps and triceps (bend and straighten elbow)
Klumpke's Palsy
- Rare injury of the lower brachial plexus (usually following breech delivery with arm above the head)
- Nerves C8 and T1 are involved
- Hand muscles and finger flexors are paralyzed
- It is extremely rare to have a true / isolated Klumpke's Palsy. The term is sometimes loosely applied to cases of complete or global brachial plexus palsy.
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Surgical management of brachial plexus injuries
The nerves of the brachial plexus originate in the neck, in the cervical spine. The nerves re-grow from the neck down the arm. This healing will occur at a rate of 1 mm per day or 1 inch per month.
A mixed or incomplete recovery may occur if the nerves do not fully reattach at their original motor and sensory targets.
Full recovery will occur only if sensory fibers reach their sensory end targets and motor fibers reach their muscle targets.
The ability to bend the elbow (biceps function) by the third month of life is an indicator of probable recovery. In addition to bicep function, active movement of the wrist, thumb and finger extension is an even stronger indicator of excellent spontaneous improvement.
Gentle range of motion exercises performed by parents, accompanied by repeated examinations by the physician, may be all that is necessary for patients with strong indicators of recovery.
The remaining patients may have limitations related to their brachial plexus injury that are not resolving. Limitations may include incomplete range of motion with one or more movements, weak muscles, or decreased sensation (feeling) through the arm. It is for these children that the remainder of our treatment efforts are focused.
MRI and EMG testing can play an important role in determining specific information regarding the location and severity of injury.
The timeframe of surgical repair is an important factor in recovery. Within 12 months, the muscles that have not already connected to nerves may have weakened to the point where it is no longer possible.
For avulsion and rupture injuries, there is no potential for full recovery unless surgical repair is done in a timely manner. For neuroma and neurapraxia injuries, the potential for improvement varies. Most patients with neurapraxia injuries have a fair prognosis of recovering spontaneously with a 90 - 100% return of function.
If surgery is needed, microsurgical nerve repair may be undertaken as early as 3 months. Procedures include:
- Neurolysis
- Removal of the constrictive scar tissue surrounding the nerve.
Neuroma Excision - When the neuroma is large it must be removed and the nerve is then reattached either with end-to-end techniques or with nerve grafts.
- Nerve Grafting
- When the gap between the nerve ends is so large that it is not possible to have a tension-free repair using the end-to-end technique, nerve grafting is used.
Neurotization - This is used generally in those cases where there is an avulsion. Donor nerves are used for the repair. The parts of the roots still attached to the spinal cord can be used as donors for avulsed nerves.
Additional procedures are available to improve the overall function of the affected limb. Procedures include:
- Arthroscopic surgery and other minimally invasive techniques
- Shoulder reconstruction
- Muscle transfers
- Rotational osteotomies
- Tendon transfers
- Elbow reconstruction
- Botox
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Treatment
Non-surgical management is also an important part of the treatment process. Occupational and / or Physical Therapy is often recommended including but not limited to range of motion, strengthening, Neuromuscular Electrical Simulation, Kinesio Taping, joint mobilization, aquatic therapy and use of orthoses.
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Life-long considerations for brachial plexus injury patients
Because your child may not be able to move the affected arm alone, it is important for you to take an active part in keeping the joints limber.
A brachial plexus injury is a life-long condition. Management often focuses on preventing or minimizing deficits and maximizing the child's capabilities at home and in the community.
It is important to remember that your child is very adaptable. Be supportive and encouraging; focus on what your child can do. Positive reinforcement will help your child to develop a healthy sense of self-esteem and promote independence.
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Contact us
For additional information on this or any Health Topic, please call the Family Resource Center, 513-636-7606, or your pediatrician.
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Written 7/04; rev. 8/04; rev. 5/06
