The brachial plexus is a rich network of nerves that originates in the upper spinal cord and extends to the upper extremities. It transmits sensory and motor impulses to each arm, hand, and shoulder. Injury to the brachial plexus can affect sensation and movement in these areas.
This article provides an overview of brachial plexus injury (BPI), including the different types, causes, and symptoms. It also outlines the treatment options for BPI and provides tips on how to prevent BPI complications.
The brachial plexus is a network of nerves that originates in the upper spinal cord. The network extends from the neck, crosses at the upper chest, and extends to the armpit.
The brachial plexus connects five nerves from the spinal cord with nerves responsible for sensation and movement in the arm and hand. A person has a brachial plexus on each side of their body.
Injury to the brachial plexus typically occurs after forceful stretching or pulling of the arm.
According to an older
The surge in injuries may be due to increasing participation in high energy sports, as well as high survival rates from motor vehicle collisions. Indeed, the article notes that 7 in 10 cases of traumatic BPIs are from traffic accidents, with 70% of these involving motorcycles.
Additional research from 2022 indicates that neonatal BPI, also known as neonatal brachial plexus palsy, is a common type of birth injury. It can happen as a result of pressure in the womb or a difficult delivery. The authors note that the incidence in the United States has decreased significantly over the past two decades, from 1.5 to 0.9 per 1,000 live births.
Brachial plexus injuries may vary in the type of injury and the degree of blunt trauma to the nerves. Healthcare professionals have classified nerve injuries, including BPIs, into four main types:
Avulsion
Nerves of the brachial plexus originate from a nerve root. Avulsion happens when the nerve root pulls out of the spinal cord as a result of blunt trauma. Most cases are due to motor vehicle accidents.
Avulsion is the most severe type of BPI because the nerves cannot grow back in or out of the spinal cord and cannot repair themselves. Avulsions can lead to loss of sensation, weakness, and paralysis and may require surgery.
Rupture
A forceful stretch can cause the nerves of the brachial plexus to tear partially or entirely, resulting in a rupture. Ruptures can cause severe pain, loss of sensation, and weakness in the arm, hand, and shoulder.
Surgery may help repair less severe ruptures.
Neuroma
A neuroma is a growth or an area of scar tissue that develops on a damaged part of a nerve. Neuromas may interfere with typical sensation and function in the affected body part.
Early surgical intervention may help prevent additional damage and complications. During surgery, a surgeon will remove the scarred nerve tissue and cap or reattach it to another nerve to prevent another neuroma from forming.
Neurapraxia
Neurapraxia is the mildest form of BPI. It occurs when nerves have stretched to the point of bruising. One common symptom is a burning or stinging sensation, which is known as brachial plexus burners or stingers.
Since there is no damage to nerve tissue, neurapraxia can resolve on its own without surgery.
The symptoms of BPI can vary depending on the location and severity of the injury.
Minor injuries
Minor injuries can be a result of stretching and compressing the brachial plexus, as can happen during contact sports.
Symptoms that may indicate a minor BPI include:
- a tingling, burning, or electric shock sensation in the shoulder and hand
- numbness and weakness in the arm
More severe injuries
People with torn or damaged nerve roots experience more intense symptoms such as:
- weakness
- severe pain in the arm and shoulder
- loss of movement and sensation in the shoulder, arm, and hand
Possible causes of BPI include:
- Blunt trauma: Trauma is one of the most common causes of BPI. Possible causes of blunt trauma include falls, motor vehicle or motorcycle collisions, and gunshot or stab wounds.
- Contact sports: Sports that involve physical contact and a risk of collisions with other players — such as football, wrestling, and martial arts — may lead to BPI. The nerves may stretch beyond their standard limit, resulting in burners and stingers.
- Complicated delivery: Birth complications, such as prolonged labor or breech presentation, may damage the upper nerves of the brachial plexus and cause a condition called Erb’s palsy.
- Cancer: Cancer cells can invade and destroy healthy nerve tissues of the brachial plexus and surrounding areas, leading to BPI. Examples of cancers that may invade these tissues include breast cancer, lung cancer, and carcinomas of the head and neck.
- Radiation therapy: While radiation therapy can eliminate cancer cells, it can also affect healthy noncancerous cells, including nerves.
- Surgical complication: Surgery to the neck can cause damage to the brachial plexus.
A person who experiences symptoms of BPI should contact a doctor immediately for a diagnosis and appropriate treatment.
A doctor will conduct a physical examination to assess immobility and loss of sensation in the upper limbs and extremities. This can help pinpoint the location of a nerve injury, as well as the type of injury and the degree of damage.
A doctor
- X-rays: An X-ray can reveal any underlying damage to vital structures following trauma.
- CT or MRI scans: These imaging techniques can reveal injury to the brachial plexus.
- Electromyography: This technique measures nerve activity in the muscles in response to electrical stimulation.
Without treatment, BPIs may lead to further complications, such as:
- Pain: Most people with BPIs experience severe pain due to nerve damage.
- Joint stiffness: Lack of shoulder, arm, and hand mobility may eventually lead to stiff joints.
- Muscle atrophy: Loss of physical activity can cause muscle loss or wasting in the upper extremities.
- Loss of sensation: People with little or no sensation in the shoulder, arm, and hand risk hurting or harming themselves without knowing.
- Permanent disability: While some BPIs are mild and resolve with time, more severe injuries can cause permanent weakness and paralysis that may not respond to surgical intervention.
Brachial plexus injury can occur alongside other conditions. Some related conditions include:
- Horner’s syndrome: This is the
medical term for a group of symptoms that occur as a result of nerve root avulsion of the brachial plexus. Symptoms include:- a small or constricted pupil
- drooping of the upper eyelid
- reduced facial sweating on one side of the face
- Erb’s palsy, or “brachial plexus birth palsy”: This condition results from damage to the upper nerves of the brachial plexus. Although it is the
most common neurological injury in newborns, adults can also develop it. Most infants recover independently, whereas adults may need surgery or rehabilitative therapy to regain nerve function. - Global palsy: This is the most severe BPI in newborns, affecting both the upper and lower brachial plexus nerves. This type involves damage to all five nerves of the brachial plexus, resulting in total paralysis of the affected arm, hand, and shoulder.
A doctor will assess the cause and severity of damage to the brachial plexus to determine the best treatment plan.
Healthcare professionals recommend two main treatment options for BPIs. These are outlined below.
Nonsurgical treatment
Most minor BPIs heal on their own. A doctor will assess a person’s symptoms and medical imaging results to determine whether the injury is likely to heal without surgery.
If a person is a good candidate for nonsurgical treatment, the doctor may recommend medications and physical therapy sessions to improve healing, reduce symptoms, and increase range of movement.
Surgical treatment
Severe BPIs cannot heal without surgical intervention. Depending on the type and extent of the injury, a neurosurgeon may perform one of the following procedures:
- Neurolysis: This procedure involves removing scar tissue from an injured nerve to improve nerve function.
- Nerve repair: This procedure involves reconnecting the torn edges of a severed nerve to repair the nerve.
- Nerve graft: A surgeon will perform a nerve graft when the space between two nerve endings is significant. The procedure involves taking a healthy nerve from another area of the body and using it to connect the two ends of the severed nerve. This procedure can help guide nerve growth, restore nerve signals, and facilitate healing.
- Nerve transfer, or “Oberlin transfer”: This involves taking a healthy donor nerve from a muscle and reattaching it to an injured nerve to restore signals to a paralyzed muscle.
- Tendon and muscle transfer: This procedure may be effective for people with a severe BPI or a complicated injury as a result of delayed treatment. it involves transferring a tendon or muscle from one part of the body to another to restore motor functions in that area.
According to a 2018 review, for the best surgical outcome, a person should undergo treatment within 3–6 months of the injury.
It is not always possible to prevent BPIs. However, a person who sustains such an injury can take steps to reduce their risk of complications. These include:
- practicing recommended physical therapy exercises
- avoiding cuts and burns
- contacting a doctor if they experience worsening symptoms
The brachial plexus is a network of nerves that originates in the neck, or cervical, region of the spinal cord and extends through the shoulders, arms, and hands. It is responsible for sensations and movement in these areas of the body.
BPI can cause weakness, numbness, or paralysis of the upper limbs or extremities, depending on the location and extent of the injury.
A person who experiences symptoms of BPI should see a doctor for a diagnosis and appropriate treatment. In less severe cases, doctors may recommend medications and physical therapy to improve healing and reduce symptoms while the nerves heal. In other cases, they may recommend surgical treatment to directly repair the affected nerves.
A person who experiences a BPI should take steps to reduce their risk of complications. These include practicing recommended physical therapy exercises, avoiding additional injuries, and contacting a doctor if they experience worsening symptoms.