Many serious athletes or people who do repetitive work can experience injuries to the nerves in the hands and arms that could end their careers. Trauma to the neck, arm or shoulder can also affect nerves and take them months to recover. A brachial plexus injury may lead to severe nerve damage.
What is Brachial Plexus?
The brachial plexus definition is a “network of nerve fibers that run from the spine, passing through the cervico-axillary canal to reach the axilla. It is formed by the ventral rami of the lower four cervical and first thoracic nerve roots (C5-C8, T1).”
In laymen’s terms, it is a group of nerves that exit the spine within the neck and run across the shoulder, into the armpit and then down the arm. They pass between the pectoralis minor and the subscapularis muscles. These muscles are attached to the ribs, the shoulder, and to the upper arm.
This group of nerves controls the movement of the muscles in the shoulder, wrist, elbow, and hand. If these nerves sustain minor damage, then the patient will usually recover in a few weeks. However, if the damage is severe, then there could be some disability of the arm.
Causes of Injuries
Damage to the nerves can be the result of them being forcibly stretched, pressure against them, or being cut, such as during surgery. If the neck and head are pushed away from the shoulder, then the nerves can become stretched.
It can also occur if the arm is forced above the head during activity. There are several injuries that can damage this group of nerves.
Whiplash from an auto accident can cause these nerves to sustain damage. A study was done with patients who sustained an injury to the nerves due to whiplash. The damage to study participants was established by:
- Continual radiating pain of the upper arm, which got worse when lifting, carrying, extending an arm(s) overhead, or by repetitive use of it.
- A positive result when a Tinel test was conducted on the nerves, which often resulted in tingling or a pins and needles sensation in scalene muscles, which connect the ribs to the spine in the neck, or the supraclavicular fossa, which is the indentation above the clavicle.
- Pain or tingling sensations could be reproduced by stressing the nerves at the shoulder, usually by having participants move their arms away from the body at a 90-degree angle or by someone holding an arm and pressing against the other shoulder, which is called a traction maneuver.
Those in the study who experienced the injury due to whiplash, of which there were significantly more women than men, reported symptoms like:
- Neck pain
- Not feeling well.
- Discomfort of the eyes.
- Tinnitus, which is ringing or buzzing in the ears.
The nerves in the shoulder can also sustain injuries by participating in sports. When a football player is hit, and his head and neck are forced back from the shoulder, an injury similar to whiplash can occur.
When heavy weights are lifted above the shoulders, such as in deadlifts, then the nerves can also sustain damage. Due to the movement of the arm and shoulder, baseball pitchers can also sustain a brachial plexus injury.
In some people, nerve damage may not be the result of an injury, but due to inflammation. The inflammation can be the result of a condition called Parsonage-Turner syndrome. It is also known as acute brachial neuritis or acute brachial neuritis syndrome.
The symptoms of this condition are a sudden pain in the shoulder and upper arm and weakness or atrophy of the muscles in the area, which gets worse over time. While the cause of this syndrome is unknown, it can be genetic and clear up on its own.
However, many doctors suspect it’s an autoimmune response and can be triggered by exposure to illnesses like viral or bacterial infections and other medical conditions. It may also be caused by vaccinations or medical procedures like surgery.
Some babies may sustain injuries during their birth if the labor occurs over a prolonged time or they get trapped in the birth canal. If the shoulders get trapped or if the neck is stretched during birth, then the injuries increase the chances of brachial plexus palsy or Erb’s palsy.
This condition happens in only one to two births out of every thousand. The arm of a baby with Erb’s palsy is rotated toward the body, and he or she has difficulty with moving their arm.
Fortunately, improvements in the arm can be made by exercising it every day. However, some babies may not be able to move their arm at all, or they may experience paralysis of the arm.
Tumors or Radiation Therapy
Pressure from benign or malignant tumors growing in the shoulder or upper arm can damage the nerves, as can receiving radiation to shrink tumors. Nerve damage can also occur from radiation treatments of the upper chest or neck.
This nerve damage is called brachial plexus neuropathy. However, there are other causes for it, including:
- Birth defects
- Exposure to toxins.
- Autoimmune responses.
- Conditions that cause inflammation.
Along with the usual symptoms some people with this neuropathy can experience a rare condition called Horner syndrome. It is the result of nerve damage interrupting the signals controlling the muscles of the face. Symptoms may include:
- Very small pupils.
- Drooping of an eyelid.
- Not being able to sweat in the affected area.
Radiation treatments can also cause brachial nerve lesions. A lesion can appear as an ulceration, wound, or abscess of the nerves.
Nerve Damage Symptoms
The symptoms that are associated with damage to this plexus are:
- A shocking or burning sensation that moves down the arm, known as burners or stingers.
- Numbness or weakness in the arm.
- Being unable to move certain muscles in the shoulder, arm, hand, or fingers.
- Severe pain.
- Neck pain.
These symptoms can occur in one or both arms. If you have them, especially after a trauma like an auto accident, a fall, or due to contact sports, you need to see a doctor.
While it is best to see a doctor as soon as possible, especially with more severe symptoms, you should make an appointment within six to seven months of their onset.
Diagnosing Nerve Damage
The treatment for this type of nerve damage will depend on the type of injury and the location. If you have symptoms of damage to the nerves, a doctor will conduct tests to accurately diagnose it.
A doctor will conduct a physical examination to test for an injury to the nerves. The tests are done to locate the injury and judge its severity. The Tinel sign test is performed by tapping areas where the nerves are located.
If the test causes shooting pain in the nerve areas, then the injury may be located farther from the spinal cord. After receiving treatment, the doctor may perform the test again to find out if the pain sensation is shooting down the arm into the hand. If so, then it indicates the injury is healing.
The doctor will also examine the arm(s) and shoulder(s) to check stability and their range of motion. Then, they may order further tests depending on their findings.
X-rays may be ordered to rule out fractures in the ribs, neck, chest, shoulder, and arm that could damage nerves. They may also have the patient breathe deeply, then take an x-ray to rule out damage to the lungs or nerves that control breathing. X-rays can also identify a structural misalignment of the cervical vertebrae that may be irritating the nerve roots.
A CT scan or brachial plexus MRI may be conducted to ascertain the extent of the damage to the nerves. The MRI may be done in addition to the CT scan to get a better look at the nerves and surrounding area. These tests are usually about three to four weeks after an injury to allow potential blood clots to dissipate.
Nerve conduction studies and muscle signal tests are done to confirm the diagnosis and locate the area of injury. They also help find out the severity of the damage and assess recovery. They are usually done about three to four weeks after the injury to allow for nerve regeneration.
If the injury is minor, then the symptoms will be treated according to their cause. Treatments may include pain relievers or anti-inflammatory drugs to allow the nerves to heal on their own. When they do, their function is usually better than with most available treatments.
If the brachial plexus injury is severe, and the nerves are not regenerating, they were cut, or if a tumor is pressed against them, then surgery may be necessary to help the nerves recover. However, sometimes surgery may not be enough to completely restore function to an arm(s) or hand(s).
If surgery is performed for other reasons in the upper extremities, then a brachial plexus block is often done to prevent an injury to the nerves.
Moderate injury to the nerves will not require surgery, but will also not recover with simple pain relieving and anti-inflammatory medication. Chiropractic or physical therapy is usually necessary to correct problems in the neck to remove the cause of the damage to the brachial plexus.
If you have any nerve damage symptoms after an accident or other trauma, see a doctor as soon as possible. Getting the injury diagnosed and treated quickly can help it recover and restore function faster.