Brachial Plexus (erbs palsy)
Brachial Plexus Anatomy
From the roots, the brachial plexus nerves branch and fuse through the shoulder and down the arm, classified into a few different sections: trunks, divisions, cords and branches. These sections are not functionally different, but help explain the complex anatomy of brachial plexus.
The brachial plexus ends in five major nerve branches that extend down the arm:
- Musculocutaneous nerve: Originates from nerve roots C5-C7 and flexes muscles in the upper arm, at both the shoulder and elbow.
- Axillary nerve: Stems from nerve roots C5 and C6; it helps the shoulder rotate and enables the arm to lift away from the body.
- Median nerve: Starts in nerve roots C6-T1 and enables movement in the forearm and parts of the hand.
- Radial nerve: Begins in nerve roots C5-T1 and controls various muscles in the upper arm, elbow, forearm and hand.
- Ulnar nerve: Rooted in C8-T1, it allows for fine motor control of the fingers.
Types of Brachial Plexus Injuries
Brachial plexus injuries are categorized according to how the nerves are damaged and the severity of the injury.
Brachial Plexus Neuropraxia (Stretch)
When the nerves are stretched to the point of injury, it is referred to as neuropraxia. There are two main ways this injury occurs: compression and traction. In a compression injury, the brachial plexus nerve root is compressed, usually by the rotation of the head. Compression neuropraxia is the most common form and generally occurs in older people.
Traction neuropraxia occurs when the nerve is pulled, usually downward. This injury is less common than compression neuropraxia, but is more common among adolescents and young adults.
These types of injuries are often referred to as brachial plexus “burners” or “stingers,” depending on whether the main symptom is a burning or stinging sensation. They can also feel like an electric shock.
Brachial Plexus Rupture
In a brachial plexus rupture, a forceful stretch causes the nerve to tear, either partially or completely. This is a more serious injury than neuropraxia. Ruptures can cause weakness in the shoulder, arm or hand and can even make certain muscles unusable. These injuries can also be associated with severe pain.
Depending on the severity and location of the rupture, these injuries can often be repaired with surgery.
Brachial Plexus Neuroma
Sometimes when nerve tissue is injured, such as from a cut during surgery, scar tissue can form as the nerve attempts to repair itself. This scar tissue is called a neuroma, and it may result in a painful knot on one of the brachial plexus nerves.
Treatment for brachial plexus neuromas includes surgical removal of the scarred nerve tissue. The surgeon then either caps the nerve or attaches it to another nerve to prevent another neuroma from forming.
Brachial Neuritis
Also called Parsonage Turner syndrome, brachial neuritis is a rare, progressive disorder of the nerves of the brachial plexus. This syndrome causes sudden, severe shoulder and upper arm pain and progresses from pain to weakness, muscle loss and even loss of sensation. This syndrome usually affects the shoulder and arm, but it can also affect the legs and diaphragm. The cause of brachial neuritis is unknown, but could be related to an autoimmune response triggered by infections, injury, childbirth or other factors.
Brachial Plexus Avulsion
A brachial plexus avulsion occurs when the root of the nerve is completely separated from the spinal cord. This injury is usually caused by trauma, such as a car or motorcycle accident. More severe than ruptures, avulsions often cause severe pain. Because it is difficult and usually impossible to reattach the root to the spinal cord, avulsions can lead to permanent weakness, paralysis and loss of feeling.
Doctor Details:-
Dr.P.S Bhandari
Brijlal Hospital,
Haldwani