What is a Brachial Plexus Injury?
The term Brachial Plexus Injury (BPI) refers to an injury to the complex set of nerves that control the muscles of the fingers, hand, arm, and shoulder. The nerves originate at the spinal cord and are formed in 3 trunks located in the upper shoulder: the upper trunk from spinal cord segments C5 and C6, the middle trunk from segment C7, and the lower trunk from segments C8 and T1.
Other Terms for BPI
Terms used to describe a BPI include Erb's Palsy (an upper trunk injury), Klumpke's Palsy (a lower trunk injury), Brachial Plexus Palsy, Erb-Duchenne Palsy, Horner's Syndrome (when facial nerves are also affected), and "Burners" or "Stingers" (usually associated with sports-related brachial plexus injuries). Torticollis is another term sometimes used in conjunction with brachial plexus injuries.
How Injuries Occur
The Brachial Plexus can be damaged in a number of different ways including accidents involving high impact conditions (automobiles, motorcycles, snowmobiles, sports) but most brachial plexus injuries occur during birth with a condition called Shoulder Dystocia (SD). The baby’s shoulder becomes “stuck” against its mother’s pubic bone changing the otherwise normal delivery into an emergency situation. Various SD maneuvers may be used to complete the delivery; but, in the process, excessive force can be applied to the baby’s neck and head resulting in stretching and/or tearing of the Brachial Plexus nerves.
More than one Brachial Plexus trunk can be injured in any of the above conditions, resulting in unique set of nerve injuries for each individual. Thus, diagnosis of the injury requires a careful neurological examination by a brachial plexus specialist to determine which nerves have been affected and the severity of the injury. Such diagnosis should be completed as soon as possible.
Types of Injuries
Injuries to the Brachial Plexus can involve:
- tearing the nerve from the spinal cord (an avulsion)
- tearing the nerve but not at the spinal cord ( a rupture)
- scar tissue where an injured nerve has tried to heal putting pressure on the nerve and disrupting signals to the muscles ( a neuroma)
- stretching but not tearing of the nerve where the nerve is able to heal itself (a praxis). This a temporary condition where the muscle regains complete function.
Denervated muscle can cause imbalances resulting in muscular and skeletal deformities in the elbow and shoulder. Also, the development of the affected arm can be compromised resulting in a shorter limb.
Injuries to the Brachial Plexus can result in full to partial paralysis of one or both arms with a temporary or, when the nerve cannot completely heal, a life time injury. While compromising muscle function and the ability to grasp, extend, and reach with the affected limb, the injury can also affect physical appearance.
Source: United Brachial Plexus Network