The plexuses - networks of interwoven nerve fibers of the spinal nerves - can be damaged by injuries, tumors, hematomas or autoimmune reactions. This can lead to pain, weakness or loss of sensation, either affecting the entire arm or leg or limited to certain areas.
The brachial plexus comprises all the nerves responsible for the function of the shoulder, arm and hand. The roots of the nerves of the upper extremity originate from the spinal cord at the level of the cervical spine and form a complex plexus in the neck area and behind the collarbone, which is known as the brachial plexus. After entering the armpit, the plexus separates into individual nerves that are responsible for the innervation of the muscles and skin.
Injuries to the brachial plexus mainly occur in high-impact trauma such as motorcycle accidents or ski falls and are often associated with other serious injuries. Less frequently, plexus injuries also occur as so-called monotrauma or single injuries, for example in the case of clumsy falls on the bent arm. A common feature of traumatic plexus injuries is that the nerve plexus is overstretched or torn off, resulting in severe damage or complete loss of arm nerve function. In our latitudes, plexus lesions rarely occur in open traumas such as gunshot wounds or impalement injuries.
The question of whether a nerve has been torn out of the spinal cord (so-called avulsion) or whether the injury is more peripheral is very important for the prognosis and understanding of the injury. Torn nerve roots cannot be reconstructed with today’s surgery and lead to permanent loss of nerve function. Torn nerves in the periphery, on the other hand, can be reconstructed using nerve grafts, which can restore a certain degree of function.
The diagnosis of a plexus injury is made on the basis of a clinical examination and a neurological assessment. Based on these findings, the pattern and severity of the injury can often be determined quite accurately. In order to obtain more information about the condition of the nerve roots, magnetic resonance imaging (MRI) is also always carried out. Today, this examination can reliably objectify the presence of a nerve avulsion from the spinal cord, which is essential for planning the reconstruction. State-of-the-art MRI examinations focused on nerves can also provide valuable additional information on the continuity of the peripheral nerves.
If there is a high degree of suspicion or a definite diagnosis of a plexus injury, surgical exploration and nerve reconstruction should be performed as soon as possible.