Brachial Plexus Injury: Types, Causes, Diagnosis, Treatment And Complications

What Is Brachial Plexsus?

The nerve network known as the brachial plexus gives the shoulder, arm, and hand movement and sensation. The nerves that support the arm leave the spinal column high in the neck, while those that support the hand and fingers leave the spinal column lower in the neck.

This nerve complex is made up of the first thoracic nerve root (T1) and four cervical nerve roots (C5–C8). Three trunks are created by the union of these roots. The upper trunk is made up of C5 and C6, the middle trunk is made up of C7, and the lower trunk is made up of C8 and T1.

Each trunk separates into a division. Flexor muscles, which lift and bend the arm, is supplies by most of the divisions of brachial plexus whereas the Extensor muscles, which straighten and lower the arm, are supplied by the rest if the divisions.

Types Of Brachial Injury

• Neuropraxia- Stretch of the Brachial Plexus occurs when the nerves are stretched to the point of damage. Compression and traction are the two basic mechanisms through which this injury happens. 
  • The brachial plexus nerve root is squeezed in a compression injury, most often as a result of head rotation. The most prevalent type is compression neuropraxia which  typically affects older persons.
• Traction neuropraxia- It is brought on by the nerve being dragged, usually downward. Compression neuropraxia is more common, despite the fact that teenagers and young adults are more prone to this injury.
• These injuries are typically referred to as "burners" or "stingers" in the brachial plexus depending on whether the major symptom is a burning or stinging sensation. An electric shock could also be experienced.
• Brachial Plexus Abrasion- When the brachial plexus ruptures, the nerve is violently stretched and either completely or partially tears. The harm is more severe than neuropraxia. After fractures, the shoulder, arm, or hand may become weakened, and some muscles may even lose their usefulness. These injuries might result in significant discomfort in addition to modest pain.
• Neuroma of the Brachial Plexus- Scar tissue may occasionally occur when nerve tissue is damaged, such as after a cut during surgery, as the nerve works to heal itself. This type of painful knot on a brachial plexus nerve is referred to as a neuroma, which is a type of scar tissue.
  • Surgery is used to remove the damaged nerve tissue from brachial plexus neuromas. For the purpose of preventing the development of another neuroma, the surgeon then either caps the nerve or connects it to another nerve.
• Neuropathy in the Arms- Sudden, acute pain in the shoulder and upper arm is a symptom of this illness, which also causes muscle weakness, atrophy, and possibly loss of sensation.
• Brachial Neuritis- Brachial neuritis, also known as Parsonage-Turner syndrome, is a rare, progressive condition that affects the brachial plexus nerves. This syndrome starts with sudden, intense shoulder and upper arm pain and develops to weakening muscle atrophy and even loss of feeling. 
  • This syndrome typically impacts the shoulder and arm, although it can also impact the legs and diaphragm. Although the exact etiology of brachial neuritis is unknown, it may be linked to an immunological reaction brought on by infections, trauma, childbirth, or other circumstances.
• Avulsions are more painful than ruptures and are more serious. Avulsions can result in persistent weakness, paralysis, and numbness since it is challenging and frequently impossible to reattach the root to the spinal cord.

Causes Of Brachial Plexus Injury During Birth

• Erb's Palsy- It presents as a  common lesion to the upper brachial plexus which results in numbness, loss of motion, and also the inability to elevate an arm, flex the elbow, or bring things closer to the mouth.
• Klumpkes Palsy- A less frequent injury affecting the lower brachial plexus, Klumpke's palsy causes loss of sensation and/or motion in the wrist and hand, including the inability to move the fingers.

Causes Of Brachial Plexus Injury In Adults

• Blunt trauma- incidents like slips and falls or car crashes.
• Sports- related injuries are common, especially in contact sports like football.
• As a result of a gunshot, the nerves are torn through or very near.
• Medical trauma-  the cutting of a nerve during surgery, the injury caused by an injection or the positioning of the body during surgery.
• Cancer- The brachial plexus is invaded by a tumor.
• Radiation therapy- The nerves are damaged as a result of radiation treatment.

Diagnosis Of Brachial Plexus Injury

• An X-ray of the neck - It helps to diagnose any fractures or any  other injuries to the bone or the tissues that surround the brachial plexus nerves.
• A brachial plexus injury may be visible through imaging tests like an MRI or CT scan, during which contrast dye may be administered.
• The nerve conduction study and the electromyogram are two tests that use needle electrodes to measure electrical activity and nerve function.
• For the purpose of allowing your doctor to track your development, these tests could be repeated every few weeks or months.

Treatment Of Brachial Plexus Injury.

• Neurolysis. The goal of this technique is to release the nerve from scar tissue.
• Nerve Grafting. The injured brachial plexus portion is removed during this treatment, and pieces of nerves from other regions of the body are used to replace it. Over time, new nerves can sprout on this bridge.
• Transfer of Nerves. When a nerve root has been severed from the spinal cord, surgeons frequently join a less significant nerve that is still functioning with a more significant nerve that is no longer functioning. For the growth of new nerves, this acts as a bypass.
• Transfer of Muscle. During a muscle transfer, your surgeon will cut a less significant muscle or tendon from another area of the body, generally the thigh, transport it to the arm, and then reattach the nerves and blood arteries that nourish the muscle.
• Reducing pain The most severe brachial plexus injuries can cause pain that is incapacitating, extremely crushing, or persistently burning. For the majority of people, this pain disappears after three years. If painkillers are unable to relieve it, your doctor may advise surgery to cut off the pain signals coming from the injured area of the spinal cord.