Brachial Plexus Injury - Causes, Symptoms And Treatment

Introduction

Many nerves carry signals from the spinal cord to the shoulders, arms, and hands. This bunch of nerves is called the brachial plexus as a whole. This bunch of nerves runs across the shoulders, arms, and forearms. They are responsible for transmitting sensory and motor signals from the spinal cord. They are accountable for making movements such as typing, lifting an object, eating, etc. In simple words, all actions you perform with your hands are due to the activity of the brachial plexus. Also, perceiving temperatures can be due to these nerves. Any minor or major injury to these nerves is called a brachial plexus injury. This read covers essential information about the brachial plexus and its injuries.

What Is the Anatomy of the Brachial Plexus?

The primary function of all the nerves in the bunch, the brachial plexus, is almost similar. They let you make movements with your hands and shoulders, and they are responsible for allowing you to perceive any temperature. The brachial plexus nerves help you find if the pan you hold is hot or cold.

However, the nerves are sectioned into the following five different branches to help with an easy understanding of the complex anatomy of the brachial plexus.

• Musculocutaneous Nerve: This nerve is responsible for flexing upper arm muscles (in the elbow region and shoulders on both sides).

• Axillary Nerve: This nerve on both sides of the body is responsible for the shoulders' rotation and helps lift the arm away from the body.

• Median Nerve: Median nerve is responsible for specific movements of the hands, especially the movements of the forearms.

• Radial Nerve: This nerve is responsible for controlling the movements of various muscles of the shoulders, elbows, forearms, and other parts of the hands.

• Ulnar Nerve: This nerve helps in moving the fingers.

What Could Be a Brachial Plexus Injury?

Any injury to any nerve that belongs to the bunch of nerves, brachial plexus, is called brachial plexus injury. It can be caused due to any abnormal stretching, compressing, or in worst cases, the nerve that belongs to the brachial plexus could be torn or ripped apart. Brachial plexus injury can happen if trauma occurs to the shoulder or hands region. They can be mild, moderate, or severe. In most mild injuries, the brachial plexus usually heals without surgical intervention. However, some severe injuries can lead to paralysis of the arms, which could be treated surgically. Sometimes, a baby can experience brachial plexus injury during birth. Brachial plexus injury usually cuts off or interrupts the regular communication between the spinal cord and the arms or shoulders depending upon the injured nerve, which leads to motor difficulties (difficulties in moving hands or arms) or loss of sensation of the hands (will not be able to feel anything like touch or different temperatures).

What Are the Different Causes of Brachial Plexus Injuries?

The brachial plexus injury can be caused due to abnormal compression, stretching, or tearing of the nerves.

Following are the common brachial plexus injury causes,

• Obstetric Brachial Plexus Injury (Brachial Plexus Injury at Birth): About one to two babies in every 1000 babies experience brachial plexus injury during vaginal birth (normal delivery). This is very common if the mother has diabetes or if the baby is more prominent in size. Also, if the baby's bottom comes out first during birth (breech position), the baby is at a higher risk of having brachial plexus injury. Brachial plexus injury during birth can present as either of the following palsies, namely,

• Erb's Palsy: This occurs due to the damage to the upper brachial plexus nerve. This leads to loss of sensation and the inability to lift the arms or flex the elbows.

• Kulmpke's Palsy: This type of palsy occurs when the lower brachial plexus nerves are injured. This injury is relatively uncommon, and if injury occurs to the lower brachial plexus, the baby will have a loss of sensation in the wrist and fingers and an inability to move the fingers or rotate the wrists.

Usually, brachial plexus injuries that occur during birth resolve independently without any treatment or surgery. However, some severe injuries during birth do require surgical intervention.

• Blunt Trauma: Trauma to the shoulders or hands might occur during road traffic accidents or falls.

• Sports Injuries: Sports injuries can also lead to brachial plexus injuries. Brachial plexus injuries are prevalent during contact sports like football.

• Gunshot Injuries: Gunshot injuries in the shoulders region may lead to brachial plexus injuries.

• Surgical Complications: Some surgeries done to the shoulder region might have complications where sharp surgical instruments might cause trauma to the brachial plexus nerves.

• Cancers: Cancers in the neck and shoulder regions might affect the brachial plexus nerves.

• Radiation Therapy: In cases of cancers that occur in the neck or shoulders, radiation therapy is done to prevent the tumor's recurrence or kill cancer cells. These high doses of ionizing radiation might sometimes cause brachial plexus injury.

What Are the Symptoms Associated With Brachial Plexus Injury?

The symptoms of brachial plexus injury depend upon the length of the brachial plexus site injured and the severity of the damage. The shoulders are affected if the upper brachial plexus nerves are injured. The forearm, wrist, and fingers are affected if the lower brachial plexus region is involved in the injury.

Some of the common symptoms associated with brachial plexus injury are discussed below,

• Burning, stinging, or severe pain in the shoulder or arm region can occur.

• Hanging arms with no feeling or control (paralysis of a hand).

• Depending on the brachial plexus length, numbness in the shoulder, arms, wrist, or fingers occurs.

How Does a Physician Diagnose Brachial Plexus Injury?

After listening to the symptoms and after looking for signs, your doctor might ask for the following tests, namely,

• X-ray to diagnose any fracture that damages the brachial plexus.

• CT (computed tomography) scan with contrast can help diagnose any trauma to the brachial plexus.

• MRI (magnetic resonance imaging) can also be done.

• Specific tests use needle electrodes to learn nerve function and electrical activity. Such tests are nerve conduction study and electromyogram.

How to Treat Brachial Plexus Injury?

Not all brachial plexus injuries require surgery as a treatment. Some mild to moderate brachial plexus injuries in babies or adults can heal themselves when supported with exercise and some medications. However, in rare instances, severe injuries to the brachial plexus might require surgical treatment to restore the nerves' normal function.

Following are some of the nonsurgical management measures followed in cases of brachial plexus injuries,

• Exercises: Certain physical exercises usually taught by a physiotherapist can help loosen the stiff joints and muscles of the shoulders and hands and thus can help with the betterment of the injury. The person affected is asked to perform everyday actions like cooking, cleaning, or daily chores to help heal.

• Corticosteroid: Ointments and injections containing corticosteroids can help a person relieve the pain associated with brachial plexus injury.

• Devices: Certain special assistive devices like compression sleeves, splints, and braces can be used to help in the healing of the brachial plexus.

Conclusion:

Brachial plexus injuries are not so uncommon. Therefore, if any of you encounter any trauma to the hand or shoulder region that is followed by numbness of parts of the hands or shoulders, make sure to meet a doctor to start the necessary diagnosis and treatment. Though brachial plexus injuries are not often life-threatening, they can cause severe damage to the quality of life. Therefore, driving and playing safely with proper precautions is essential to avoid such injuries. Because, of course, prevention is always and will always be better than cure.