CONDITIONS TREATED

The brachial plexus is formed by five spinal nerves from C5 to C8 and one thoracic T1, which exit from the spinal cord and emerge in the posterior triangle of the neck where they constitute the upper (C5-C6), middle (C7) and lower trunk (C8-T1).

The brachial plexus connects the brain and the spinal cord to all the structures in the upper limb, providing control of movement and perception of varied sensations. All the trunks divide just above the clavicle level. The suprascapular and axillary nerves, formed mainly by the 5th cervical nerve, supply the muscles of the shoulder. The musculocutaneous nerve, which is mainly formed by the 5th and the 6th cervical nerves, innervates the muscles for elbow flexion. The radial nerve, which is formed by 6th, 7th and 8th cervical nerves, passes to the posterior aspect of the limb and gives branches to muscles responsible for elbow, wrist and fingers extension. The median and ulnar nerves pass down to the anterior aspect of the limb and they are responsible for innervation of the muscles of flexion of wrist and fingers and all the small muscles of the hand. These two major nerves bring sensory impulses from the hand to the cerebral cortex.

Injury in adults usually results from motorcycle or car accidents or sports trauma. These injuries may involve each individual root:

• Avulsion – the root is torn from the spinal cord.
• Rupture - a tear is located at the root level.
• Lesion in continuity – the nerve is ruptured inside but still in continuity outside.

Symptoms of brachial plexus injury can include loss of sensation or partial or complete paralysis in the limb. When pain with neuropathic characteristics is present from the beginning the most likely diagnosis is of avulsion. If there is a Tinel’s sign (an electric sensation shooting down the arm) when tapping in the posterior triangle of the neck the most likely diagnosis is rupture. An urgent clinical assessment is always required and an urgent operation performed if indicated. The outcome of nerve repairs is significantly better if carried out within hours/days from the injury.

Secondary surgery at a later stage, even after many years by means of muscular transfers can improve limb function. Physiotherapy and occupational therapy are essential in the rehabilitation process and must be started as soon as the clinical picture allows it and must be supervised by the treating surgeon.