What is the brachial plexus and what is its function?
The brachial plexus is a plexus of nerves of the peripheral nervous system formed from the anterior branches of the spinal nerves.
The brachial plexus is so important and disorders so fatal because numerous nerves lead from it to the arms, shoulder, and chest. Nerves for the arm, shoulder, and chest originate from it.
The brachial plexus provides motor supply to tissues and organs with nerves to the shoulder and chest muscles, but at the same time it also provides that sensitive supply to the arm and hand.
Outline and Topographical Division
The brachial plexus is structurally divided into three sections: the trunci (trunks), the fasciculi (bundles), and the nerves (nerves) originating and arising from them.
Topographically, on the other hand, it is divided into two sections:
The pars supraclaviculari, located above the clavicle, and the pars infraclavicularis, located below the clavicle.
In the pars supraclaviculari there are 3 trunci, superior, medius and inferior and the following nerves: dorsal scapular nerve (C4, C5), subclavian nerve (C5, C6), thoracic long nerve (C5-C7) and suprascapular nerve (C4-C6).
Three fasciculi (lateralis, medialis, and posterior) of the brachial plexus are located in the pars infraclavicularis. The fasciculi and their branches in detail:
Fasciculus lateralis contains the musculocutaneous nerve and median nerve (radix lateralis). Fasciculus medialis, on the other hand, encloses ulnar nerve, cutaneus brachii medialis nerve, cutaneus antebrachii medialis nerve, and median nerve (radix medialis) branches. Fasciculus posterior includes radial nerve and axillary nerve.
Diseases and Disorders
Due to the nature of the brachial plexus, the question of which parts of the body are affected by disorders and diseases is answered by which plexus is damaged.
If it is the rostral brachial plexus, the shoulders are affected and impaired.
If it is the caudal brachial plexus, the hands are conductive, while disorders of the lumbosacral plexus affect the legs.
Disorders of the plexus usually result from compression or trauma. In newborns, for example, this means excessive or apruptive pulling on the arm, which is not yet strong enough or secured.
In adults, on the other hand, it usually requires trauma, such as a fall that overextends the neck against the shoulder or invasion by a metastatic tumor. Also, in patients receiving anticoagulants, for example, a hematoma may compress the plexus.
There are a host of other causes that can lead to disease in various parts of the brachial plexus. Those other causes include, but are not reduced to, radiation-induced fibrosis and diabetes.
Acute brachial plexus neuritis or neuralgic shoulder amyotrophies occur primarily in men and young adults.
Causes are largely unknown, but viral and immunological-inflammatory processes are suspected. Injuries to the brachial plexus (brachial plexus) are usually caused by major external forces. At the same time, a distinction is made here between open or closed injuries.
Open injuries are usually inspected immediately at the time of wound care, thus initiating or planning treatment and recovery of the injured nerves.
In the case of closed injuries, the spontaneous course and recovery of the affected or injured nerves are initially observed and documented for three months. If regeneration has not occurred during this time, surgical procedures are enlisted to initiate reconstruction of the nerve plexuses.
Typical symptoms and complaints of disorders and diseases of the brachial plexus
Typical symptoms include extremity pain and motor or sensory defects and dysfunction. Those symptoms are complicated and difficult to attribute because they cannot be traced to a single nerve root.
Muscles most commonly affected include the serratus anterior muscle, which has the function of pulling the scapula ventrally and facilitating shoulder rotation.
Diagnosis of Brachial Plexus Disorders
There are several diagnostic options for determining disease or disorders of the brachial plexus.
Examination of the brachial plexus is made possible indirectly by neurologic functional testing or directly by neurophysiologic diagnosis as well as neuroradiologic imaging.
Commonly used diagnostic tools include performing an MRI or CT of the appropriate plexus, as well as electromyographies and nerve conduction studies.
Electromyographies are performed to clarify the anatomic distribution of the injury or disorder. MRI and CT, on the other hand, to detect abnormalities such as tumors and hematomas and to counteract them accordingly in treatment.
The diagnosis of plexus disease is ultimately made based on clinical findings.
Treatment Options for the Brachial Plexus
There is no general solution for diseases or disorders of the brachial plexus; treatment is causally oriented.
The commonly prescribed corticosteroids have no proven benefit for brachial plexus disorders.
Surgical intervention may be indicated when injury, hematoma, and benign or metastatic tumors are found in the patient.
In the case of metastases, radiation and chemotherapy are also part of the treatment.
During surgical procedures on the arm, the brachial plexus is often turned off. This form of anesthesia is also called plexus blockade.
In reconstruction, a distinction is made between decompression and freeing the nerve from scar tissue and nerve interposition.
Here, a donor nerve from the lower leg, which is responsible for sensation in the lateral sole of the foot, is used to bridge an irreversibly damaged nerve on the brachial plexus.
Secondary functional surgery can also be used later to partially restore unrecovered functions after individual consultation.
Brachial plexus treatment in Vienna at Wiener Privatklinik
If you are suffering from a disease or disorder of the brachial plexus, contact us today or visit the Millesi Center for peripheral nerve surgery, brachial plexus surgery, reconstructive surgery and hand surgery directly.