Brachial Plexus Injuries

Brachial Plexus – Damage to Network of Nerves

Brachial plexus is a network of nerves which come from the spinal cord in the neck and travel down the arm. These nerves tend to control the muscles of the shoulder, elbow, wrist and the hand. The nerves supporting the arm exit at the spinal column high in the neck and those supporting the hand and fingers exit lower in the neck. The nerve complex comprises of four cervical nerve roots – C5-C8 and the first thoracic nerve root – T1.

These roots join together to form three trucks, C5-C6 form the upper truck, while C7 continues as the middle trunk and C8-T1 form the lower trunk. Individual trunk splits into a division and half the division altogether supply flexor muscles, which can lift and bend the arm while the others supply the extensor muscles which straighten the arm and helps to bring it down. Brachial plexus injuries are caused by damage to these nerves some of which could be minor and recover completely in some weeks. Other injuries could be severe causing permanent disability in the arm. Brachial plexus injuries could take place due to shoulder trauma, inflammation or tumours. At times it could occur during childbirth when the infant’s shoulder tends to get stuck during delivery and the nerves could stretch or tear.

Causes – Stretching/Pressure/Cutting

Some cases of these injuries may heal without much treatment. Several kids who tend to get injured during birth improve within a period of 3 to 4 months of age and treatment comprises of physical therapy and in some instances with surgery.

The nerves could get damaged from stretching, pressure or cutting wherein stretching could take place when the head and neck are forced backward or away from the shoulder which could take place during a motorcycle fall or a car accident. If it gets severe, the nerves could tear out of the spinal cord in the neck. Pressure, takes place during crushing of the brachial plexus between the collarbone and the first rib which could take place during a fracture of dislocation and swelling due to excessive bleeding or injured soft tissues could also lead to an injury.

Tests/Treatment

These nerve injuries could block signals to and from the brain, thus preventing the muscles of the arm and the hand from proper function, causing loss of feeling in those areas. Some injuries will not recover on their own and an early examination by the physicians is essential while other injuries could recover with time and therapy. Whenever an injury does not tend to improve, other surgical technique could be utilised for improvement.To identify the injuries a series of test need to be conducted of the arm and hand to check the strength of muscles and presence of feeling in the various areas. Additional tests like an MRI scan or CT scan myelography could also be used.

A Nerve Condition Study/Electromyogram – NCS/EMG, a test which measures the electrical activity transmitted by nerves and muscles could also be done. When nerve recovery does not happen in some cases, a tendon transfer surgery could be done. Whenever a sensory nerve is injured, the person should be cautious not to burn or cut the finger since there is no sensation in the affected area and the brain does not interpret the new nerve signal. A procedure called sensory re-education is needed to improve muscle control and feeling in the hand or fingers. The physician could recommend proper therapy depending on the nature of the injury.